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Bibliography on: Symbiosis

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ESP: PubMed Auto Bibliography 10 Dec 2018 at 01:34 Created: 


Symbiosis refers to an interaction between two or more different organisms living in close physical association, typically to the advantage of both. Symbiotic relationships were once thought to be exceptional situations. Recent studies, however, have shown that every multicellular eukaryote exists in a tight symbiotic relationship with billions of microbes. The associated microbial ecosystems are referred to as microbiome and the combination of a multicellular organism and its microbiota has been described as a holobiont. It seems "we are all lichens now."

Created with PubMed® Query: symbiosis NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

RevDate: 2018-12-06

Vernocchi P, Del Chierico F, Russo A, et al (2018)

Gut microbiota signatures in cystic fibrosis: Loss of host CFTR function drives the microbiota enterophenotype.

PloS one, 13(12):e0208171 pii:PONE-D-17-43072.

BACKGROUND: Cystic fibrosis (CF) is a disorder affecting the respiratory, digestive, reproductive systems and sweat glands. This lethal hereditary disease has known or suspected links to the dysbiosis gut microbiota. High-throughput meta-omics-based approaches may assist in unveiling this complex network of symbiosis modifications.

OBJECTIVES: The aim of this study was to provide a predictive and functional model of the gut microbiota enterophenotype of pediatric patients affected by CF under clinical stability.

METHODS: Thirty-one fecal samples were collected from CF patients and healthy children (HC) (age range, 1-6 years) and analysed using targeted-metagenomics and metabolomics to characterize the ecology and metabolism of CF-linked gut microbiota. The multidimensional data were low fused and processed by chemometric classification analysis.

RESULTS: The fused metagenomics and metabolomics based gut microbiota profile was characterized by a high abundance of Propionibacterium, Staphylococcus and Clostridiaceae, including Clostridium difficile, and a low abundance of Eggerthella, Eubacterium, Ruminococcus, Dorea, Faecalibacterium prausnitzii, and Lachnospiraceae, associated with overexpression of 4-aminobutyrate (GABA), choline, ethanol, propylbutyrate, and pyridine and low levels of sarcosine, 4-methylphenol, uracil, glucose, acetate, phenol, benzaldehyde, and methylacetate. The CF gut microbiota pattern revealed an enterophenotype intrinsically linked to disease, regardless of age, and with dysbiosis uninduced by reduced pancreatic function and only partially related to oral antibiotic administration or lung colonization/infection.

CONCLUSIONS: All together, the results obtained suggest that the gut microbiota enterophenotypes of CF, together with endogenous and bacterial CF biomarkers, are direct expression of functional alterations at the intestinal level. Hence, it's possible to infer that CFTR impairment causes the gut ecosystem imbalance.This new understanding of CF host-gut microbiota interactions may be helpful to rationalize novel clinical interventions to improve the affected children's nutritional status and intestinal function.

RevDate: 2018-12-06

Yoshikawa A, Goto R, A Asakura (2018)

Morphology and Habitats of the Hermit-Crab-Associated Calyptraeid Gastropod Ergaea walshi.

Zoological science, 35(6):494-504.

Ergaea walshi, a gastropod with a markedly flat shell, often lives inside empty snail shells occupied by hermit crabs. We investigated its lifestyle, shell growth pattern, and habitat preference for host hermit crabs and host snail shells. Four hundred sixteen snail shells, including 363 shells with hermit crabs and 53 empty shells, were collected from intertidal zones of sandy and muddy flats around Kii Peninsula, Japan. The specimens comprised seven hermit crab species occupying 24 shell species; E. walshi was harbored in 13.2% of snail shells with hermit crabs and 17.0% of those without hermit crabs. Although no preference was detected for particular species of hermit crab or snail shell, E. walshi preferred to live inside of snail shells with wider apertures used by comparatively bigger hermit crabs. This suggests that the occurrence of E. walshi was influenced by host size rather than host species. When looking at growth patterns, we found that the attached shell portion of E. walshi continued to be enlarged horizontally, while growth in shell height slowed at approximately 5.0 mm. The conspicuously flattened shell of E. walshi is considered as a growth pattern for adapting to the narrow space within the snail shell occupied by hermit crabs. Consistent with this idea, our comparison of shell growth patterns in 23 calyptraeid species showed that shell of E. walshi is the flattest in this family.

RevDate: 2018-12-06

Kountche BA, Novero M, Jamil M, et al (2018)

Effect of the strigolactone analogs methyl phenlactonoates on spore germination and root colonization of arbuscular mycorrhizal fungi.

Heliyon, 4(11):e00936 pii:e00936.

Strigolactones (SLs), a novel class of plant hormones, are key regulator of plant architecture and mediator of biotic interactions in the rhizosphere. Root-released SLs initiate the establishment of arbuscular mycorrhizal (AM) symbiosis by inducing spore germination and hyphal branching in AM fungi (AMF). However, these compounds also trigger the germination of root parasitic weeds, paving the way for deleterious infestation. Availability of SLs is required for investigating of their functions and also for application in agriculture. However, natural SLs are difficult to synthesize due to their complex structure and cannot be isolated at large scale, as they are released at very low concentrations. Therefore, there is a need for synthetic SL analogs. Recently, we reported on the development of simple SL analogs, methyl phenlactonoates (MPs), which show high SL activity in plants. Here, we investigate the effect of MP1, MP3 and the widely used SL-analog GR24 on AMF spore germination and host root colonization. Our results show that MP1 and MP3 inhibit AMF spore germination, but promote the intra-radical root colonization, both more efficiently than GR24. These results indicate that field application of MP1 and MP3 does not have negative impact on mycorrhizal fungi. In conclusion, our data together with the previously reported simple synthesis, high activity in regulating plant architecture and inducing Striga seed germination, demonstrate the utility of MP1 and MP3 as for field application in combating root parasitic weeds by inducing germination in host's absence.

RevDate: 2018-12-06

Bertoloni Meli S, F Bashey (2018)

Trade-off between reproductive and anti-competitor abilities in an insect-parasitic nematode-bacteria symbiosis.

Ecology and evolution, 8(22):10847-10856 pii:ECE34538.

Mutualistic symbionts can provide diverse benefits to their hosts and often supply key trait variation for host adaptation. The bacterial symbionts of entomopathogenic nematodes play a crucial role in successful colonization of and reproduction in the insect host. Additionally, these symbionts can produce a diverse array of antimicrobial compounds to deter within-host competitors. Natural isolates of the symbiont, Xenorhabdus bovienii, show considerable variation in their ability to target sympatric competitors via bacteriocins, which can inhibit the growth of sensitive Xenorhabdus strains. Both the bacteria and its nematode partner have been shown to benefit from bacteriocin production when within-host competition with a sensitive competitor occurs. Despite this benefit, several isolates of Xenorhabdus do not inhibit sympatric strains. To understand how this variation in allelopathy could be maintained, we tested the hypothesis that inhibiting isolates face a reproductive cost in the absence of competition. We tested this hypothesis by examining the reproductive success of inhibiting and non-inhibiting isolates coupled with their natural nematode host in a non-competitive context. We found that nematodes carrying non-inhibitors killed the insect host more rapidly and were more likely to successfully reproduce than nematodes carrying inhibitors. Lower reproductive success of inhibiting isolates was repeatable across nematode generations and across insect host species. However, no difference in insect mortality was observed between inhibiting and non-inhibiting isolates when bacteria were injected into insects without their nematode partners. Our results indicate a trade-off between the competitive and reproductive roles of symbionts, such that inhibiting isolates, which are better in the face of within-host competition, pay a reproductive cost in the absence of competition. Furthermore, our results support the hypothesis that symbiont variation within populations can be maintained through context-dependent fitness benefits conferred to their hosts. As such, our study offers novel insights into the selective forces maintaining variation within a single host-symbiont population and highlights the role of competition in mutualism evolution.

RevDate: 2018-12-06

Burmester EM, Breef-Pilz A, Lawrence NF, et al (2018)

The impact of autotrophic versus heterotrophic nutritional pathways on colony health and wound recovery in corals.

Ecology and evolution, 8(22):10805-10816 pii:ECE34531.

For animals that harbor photosynthetic symbionts within their tissues, such as corals, the different relative contributions of autotrophy versus heterotrophy to organismal energetic requirements have direct impacts on fitness. This is especially true for facultatively symbiotic corals, where the balance between host-caught and symbiont-produced energy can be altered substantially to meet the variable demands of a shifting environment. In this study, we utilized a temperate coral-algal system (the northern star coral, Astrangia poculata, and its photosynthetic endosymbiont, Symbiodinium psygmophilum) to explore the impacts of nutritional sourcing on the host's health and ability to regenerate experimentally excised polyps. For fed and starved colonies, wound healing and total colony tissue cover were differentially impacted by heterotrophy versus autotrophy. There was an additive impact of positive nutritional and symbiotic states on a coral's ability to initiate healing, but a greater influence of symbiont state on the recovery of lost tissue at the lesion site and complete polyp regeneration. On the other hand, regardless of symbiont state, fed corals maintained a higher overall colony tissue cover, which also enabled more active host behavior (polyp extension) and endosymbiont behavior (photosynthetic ability of Symbiondinium). Overall, we determined that the impact of nutritional state and symbiotic state varied between biological functions, suggesting a diversity in energetic sourcing for each of these processes.

RevDate: 2018-12-06

Bolin LG, Benning JW, DA Moeller (2018)

Mycorrhizal interactions do not influence plant-herbivore interactions in populations of Clarkia xantiana ssp. xantiana spanning from center to margin of the geographic range.

Ecology and evolution, 8(22):10743-10753 pii:ECE34523.

Multispecies interactions can be important to the expression of phenotypes and in determining patterns of individual fitness in nature. Many plants engage in symbiosis with arbuscular mycorrhizal fungi (AMF), but the extent to which AMF modulate other species interactions remains poorly understood. We examined multispecies interactions among plants, AMF, and insect herbivores under drought stress using a greenhouse experiment and herbivore choice assays. The experiment included six populations of Clarkia xantiana (Onagraceae), which span a complex environmental gradient in the Southern Sierra Nevada of California. Clarkia xantiana's developing fruits are commonly attacked by grasshoppers at the end of the growing season, and the frequency of attack is more common in populations from the range center than range margin. We found that AMF negatively influenced all metrics of plant growth and reproduction across all populations, presumably because plants supplied carbon to AMF but did not benefit substantially from resources potentially supplied by the AMF. The fruits of plants infected with AMF did not differ from those without AMF in their resistance to grasshoppers. There was significant variation among populations in damage from herbivores but did not reflect the center-to-margin pattern of herbivory observed in the field. In sum, our results do not support the view that AMF interactions modulate plant-herbivore interactions in this system.

RevDate: 2018-12-06

Temprano-Vera F, Rodríguez-Navarro DN, Acosta-Jurado S, et al (2018)

Sinorhizobium fredii Strains HH103 and NGR234 Form Nitrogen Fixing Nodules With Diverse Wild Soybeans (Glycine soja) From Central China but Are Ineffective on Northern China Accessions.

Frontiers in microbiology, 9:2843.

Sinorhizobium fredii indigenous populations are prevalent in provinces of Central China whereas Bradyrhizobium species (Bradyrhizobium japonicum, B. diazoefficiens, B. elkanii, and others) are more abundant in northern and southern provinces. The symbiotic properties of different soybean rhizobia have been investigated with 40 different wild soybean (Glycine soja) accessions from China, Japan, Russia, and South Korea. Bradyrhizobial strains nodulated all the wild soybeans tested, albeit efficiency of nitrogen fixation varied considerably among accessions. The symbiotic capacity of S. fredii HH103 with wild soybeans from Central China was clearly better than with the accessions found elsewhere. S. fredii NGR234, the rhizobial strain showing the broadest host range ever described, also formed nitrogen-fixing nodules with different G. soja accessions from Central China. To our knowledge, this is the first report describing an effective symbiosis between S. fredii NGR234 and G. soja. Mobilization of the S. fredii HH103 symbiotic plasmid to a NGR234 pSym-cured derivative (strain NGR234C) yielded transconjugants that formed ineffective nodules with G. max cv. Williams 82 and G. soja accession CH4. By contrast, transfer of the symbiotic plasmid pNGR234a to a pSym-cured derivative of S. fredii USDA193 generated transconjugants that effectively nodulated G. soja accession CH4 but failed to nodulate with G. max cv. Williams 82. These results indicate that intra-specific transference of the S. fredii symbiotic plasmids generates new strains with unpredictable symbiotic properties, probably due to the occurrence of new combinations of symbiotic signals.

RevDate: 2018-12-06

Tena G (2018)

Symbiosis gatekeeper.

Nature plants, 4(12):982.

RevDate: 2018-12-06

Brottier L, Chaintreuil C, Simion P, et al (2018)

A phylogenetic framework of the legume genus Aeschynomene for comparative genetic analysis of the Nod-dependent and Nod-independent symbioses.

BMC plant biology, 18(1):333 pii:10.1186/s12870-018-1567-z.

BACKGROUND: Among semi-aquatic species of the legume genus Aeschynomene, some have the property of being nodulated by photosynthetic Bradyrhizobium lacking the nodABC genes necessary for the synthesis of Nod factors. Knowledge of the specificities underlying this Nod-independent symbiosis has been gained from the model legume Aeschynomene evenia but our understanding remains limited due to the lack of comparative genetics with related taxa using a Nod factor-dependent process. To fill this gap, we combined different approaches to perform a thorough comparative analysis in the genus Aeschynomene.

RESULTS: This study significantly broadened previous taxon sampling, including in allied genera, in order to construct a comprehensive phylogeny. In the phylogenetic tree, five main lineages were delineated, including a novel lineage, the Nod-independent clade and another one containing a polytomy that comprised several Aeschynomene groups and all the allied genera. This phylogeny was matched with data on chromosome number, genome size and low-copy nuclear gene sequences to reveal the diploid species and a polytomy containing mostly polyploid taxa. For these taxa, a single allopolyploid origin was inferred and the putative parental lineages were identified. Finally, nodulation tests with different Bradyrhizobium strains revealed new nodulation behaviours and the diploid species outside of the Nod-independent clade were compared for their experimental tractability and genetic diversity.

CONCLUSIONS: The extended knowledge of the genetics and biology of the different lineages sheds new light of the evolutionary history of the genus Aeschynomene and they provide a solid framework to exploit efficiently the diversity encountered in Aeschynomene legumes. Notably, our backbone tree contains all the species that are diploid and it clarifies the genetic relationships between the Nod-independent clade and the Nod-dependent lineages. This study enabled the identification of A. americana and A. patula as the most suitable species to undertake a comparative genetic study of the Nod-independent and Nod-dependent symbioses.

RevDate: 2018-12-03

Hsiao CC, Sieber S, Georgiou A, et al (2018)

Synthesis and Biological Evaluation of the Novel Growth Inhibitor Streptol Glucoside, Isolated from an Obligate Plant Symbiont.

Chemistry (Weinheim an der Bergstrasse, Germany) [Epub ahead of print].

The plant Psychotria kirkii hosts an obligatory bacterial symbiont, Candidatus Burkholderia kirkii, in nodules on their leaves. Recently, a glucosylated derivative of (+)-streptol, (+)-streptol glucoside, was isolated from the nodulated leaves and was found to possess a plant growth inhibitory activity. To establish a structure activity relationship study, a convergent strategy was developed to obtain several pseudosugars from a single synthetic precursor. Furthermore, the glucosylation of streptol was investigated in detail and conditions affording specifically the alpha or beta glucosidic anomer were identified. Although (+)-streptol was the most active compound, its concentration in P. kirkii plant leaves extract was approximately 10 fold lower than that of (+)-streptol glucoside. These results provide compelling evidence that the glucosylation of (+)-streptol protects the plant host against the growth inhibitory effect of the compound, which might constitute a molecular cornerstone for this successful plant-bacteria symbiosis.

RevDate: 2018-12-03

Wasilko NP, Larios-Valencia J, Steingard CH, et al (2018)

Sulfur availability for Vibrio fischeri growth during symbiosis establishment depends on biogeography within the squid light organ.

Molecular microbiology [Epub ahead of print].

The fitness of host-associated microbes depends on their ability to access nutrients in vivo. Identifying these mechanisms is significant for understanding how microbes have evolved to fill specific ecological niches within a host. Vibrio fischeri is a bioluminescent bacterium that colonizes and proliferates within the light organ of the Hawaiian bobtail squid, which provides an opportunity to study how bacteria grow in vivo. Here, the transcription factor CysB is shown to be necessary for V. fischeri both to grow on several sulfur sources in vitro and to establish symbiosis with juvenile squid. CysB is also found to regulate several genes involved in sulfate assimilation and to contribute to the growth of V. fischeri on cystine, which is the oxidized form of cysteine. A mutant that grows on cystine but not sulfate could establish symbiosis, suggesting that V. fischeri acquires nutrients related to this compound within the host. Finally, CysB-regulated genes are shown to be differentially expressed among the V. fischeri populations occupying the various colonization sites found within the light organ. Together, these results suggest the biogeography of V. fischeri populations within the squid light organ impacts the physiology of this symbiotic bacterium in vivo through CysB-dependent gene regulation. This article is protected by copyright. All rights reserved.

RevDate: 2018-12-03

Pardo-De la Hoz CJ, Magain N, Lutzoni F, et al (2018)

Contrasting Symbiotic Patterns in Two Closely Related Lineages of Trimembered Lichens of the Genus Peltigera.

Frontiers in microbiology, 9:2770.

Species circumscription is key to the characterization of patterns of specificity in symbiotic systems at a macroevolutionary scale. Here, a worldwide phylogenetic framework was used to assess the biodiversity and symbiotic patterns of association among partners in trimembered lichens from the genus Peltigera, section Chloropeltigera. We sequenced six loci of the main fungal partner and performed species discovery and validation analyses to establish putative species boundaries. Single locus phylogenies were used to establish the identity of both photobionts, Nostoc (cyanobacterium) and Coccomyxa (green alga). Distribution and specificity patterns were compared to the closely related clade, section Peltidea, which includes mainly Peltigera species with trimembered thalli. For section Chloropeltigera, eight fungal species (including five newly delimited putative species) were found in association with nine Nostoc phylogroups and two Coccomyxa species. In contrast, eight fungal species (including three newly delimited putative species) in section Peltidea were found in association with only four Nostoc phylogroups and the same two Coccomyxa species as for section Chloropeltigera. This difference in cyanobiont biodiversity between these two sections can potentially be explained by a significantly higher frequency of sexual reproductive structures in species from section Chloropeltigera compared to section Peltidea. Therefore, horizontal transmission of the cyanobiont might be more prevalent in Chloropeltigera species, while vertical transmission might be more common in Peltidea species. All Peltigera species in section Chloropeltigera are generalists in their association with Nostoc compared to more specialized Peltigera species in section Peltidea. Constrained distributions of Peltigera species that associate strictly with one species of green algae (Coccomyxa subellipsoidea) indicate that the availability of the green alga and the specificity of the interaction might be important factors limiting geographic ranges of trimembered Peltigera, in addition to constraints imposed by their interaction with Nostoc partners and by climatic factors.

RevDate: 2018-12-03

Nazha A (2018)

The MDS genomics-prognosis symbiosis.

Hematology. American Society of Hematology. Education Program, 2018(1):270-276.

Myelodysplastic syndromes (MDS) are clonal disorders characterized by the accumulation of complex genomic abnormalities that define disease phenotype, prognosis, and the risk of transformation to acute myeloid leukemia. The clinical manifestations and overall outcomes of MDS are very heterogeneous with an overall survival that can be measured in years for some patients to a few months for others. Prognostic scoring systems are important staging tools that aid physicians in their treatment recommendations and decision-making and can help patients understand their disease trajectory and expectations. Several scoring systems have been developed in MDS with the International Prognostic Scoring System and its revised version, the most widely used systems in clinical practice and trial eligibility. These models and others use mainly clinical variables that are obtained from bone marrow biopsy and peripheral blood measurements. Adding molecular data to current models may improve its predictive power but the ultimate method to incorporate this information remains a work in progress. Novel methods to develop a personalized prediction model that provides outcomes that are specific for a patient are currently under way and may change how we think about risk stratification in MDS patients in the future.

RevDate: 2018-12-03

Tokuda G, Mikaelyan A, Fukui C, et al (2018)

Fiber-associated spirochetes are major agents of hemicellulose degradation in the hindgut of wood-feeding higher termites.

Proceedings of the National Academy of Sciences of the United States of America pii:1810550115 [Epub ahead of print].

Symbiotic digestion of lignocellulose in wood-feeding higher termites (family Termitidae) is a two-step process that involves endogenous host cellulases secreted in the midgut and a dense bacterial community in the hindgut compartment. The genomes of the bacterial gut microbiota encode diverse cellulolytic and hemicellulolytic enzymes, but the contributions of host and bacterial symbionts to lignocellulose degradation remain ambiguous. Our previous studies of Nasutitermes spp. documented that the wood fibers in the hindgut paunch are consistently colonized not only by uncultured members of Fibrobacteres, which have been implicated in cellulose degradation, but also by unique lineages of Spirochaetes. Here, we demonstrate that the degradation of xylan, the major component of hemicellulose, is restricted to the hindgut compartment, where it is preferentially hydrolyzed over cellulose. Metatranscriptomic analysis documented that the majority of glycoside hydrolase (GH) transcripts expressed by the fiber-associated bacterial community belong to family GH11, which consists exclusively of xylanases. The substrate specificity was further confirmed by heterologous expression of the gene encoding the predominant homolog. Although the most abundant transcripts of GH11 in Nasutitermes takasagoensis were phylogenetically placed among their homologs of Firmicutes, immunofluorescence microscopy, compositional binning of metagenomics contigs, and the genomic context of the homologs indicated that they are encoded by Spirochaetes and were most likely obtained by horizontal gene transfer among the intestinal microbiota. The major role of spirochetes in xylan degradation is unprecedented and assigns the fiber-associated Treponema clades in the hindgut of wood-feeding higher termites a prominent part in the breakdown of hemicelluloses.

RevDate: 2018-12-03

Shaaban M, Elgaml A, EE Habib (2018)

Biotechnological applications of quorum sensing inhibition as novel therapeutic strategies for multidrug resistant pathogens.

Microbial pathogenesis pii:S0882-4010(18)30585-0 [Epub ahead of print].

High incidence of antibiotic resistance among bacterial clinical isolates necessitates the discovery of new targets for inhibition of microbial pathogenicity without stimulation of microbial resistance. This could be achieved by targeting virulence determinants which cause host damage and disease. Many pathogenic bacteria elaborate signaling molecules for cellular communication. This signaling system is named quorum sensing system (QS), and it is contingent on the bacterial population density and mediated by signal molecules called pheromones or autoinducers (AIs). Bacteria utilize QS to regulate activities and behaviors including competence, conjugation, symbiosis, virulence, motility, sporulation, antibiotic production, and biofilm formation. Hence, targeting bacterial communicating signals and suppression of QS exhibit a fundamental approach for competing microbial communication. In this review, we illustrate the common up to date approaches to utilize QS circuits in pathogenic bacteria, including Vibrio fischeri, Pseudomonas aeruginosa, Escherichia coli and Acinetobacter baumannii, as novel therapeutic targets.

RevDate: 2018-12-03

Dargahi N, Johnson J, Donkor O, et al (2019)

Immunomodulatory effects of probiotics: Can they be used to treat allergies and autoimmune diseases?.

Maturitas, 119:25-38.

As a person ages, physiological, immunological and gut microbiome changes collectively result in an array of chronic conditions. According to the 'hygiene hypothesis' the increasing prevalence of immune-mediated disorders may be related to intestinal dysbiosis, leading to immune dysfunction and associated conditions such as eczema, asthma, allergies and autoimmune diseases. Beneficial probiotic bacteria can be utilized by increasing their abundance within the gastrointestinal lumen, which in turn will modulate immune cells, such as, T helper (Th)-1, Th2, Th17, regulatory T (Treg) cells and B cells, which have direct relevance to human health and the pathogenesis of immune disorders. Here, we describe the cross-talk between probiotics and the gastrointestinal immune system, and their effects in relation to inflammatory bowel disease, multiple sclerosis, allergies and atopic dermatitis.

RevDate: 2018-12-03

Wang H, Tang W, Zhang R, et al (2018)

Analysis of enzyme activity, antibacterial activity, antiparasitic activity and physico-chemical stability of skin mucus derived from Amphiprion clarkii.

Fish & shellfish immunology pii:S1050-4648(18)30785-X [Epub ahead of print].

Recently, mucosal surfaces, especially fish skin and its secreted mucus, have attracted significant interest from immunologists. Amphiprion clarkii, a member of the family Pomacentridae, lives symbiosis with sea anemones and has a good resistance to common seawater bacterial diseases and parasites owing to the protection from its abundant skin mucus. In the present work, the activity of immune-related enzymes (lysozyme, protease, antiprotease, cathepsin B, alkaline phosphatase and peroxidase), the antibacterial activity against two Gram-positive bacteria and five Gram-negative bacteria, the antiparasitic activity against the pathogen of marine white spot disease (Cryptocaryon irritans theronts) and the physico-chemical stability (to pH and heat) of the skin mucus of A. clarkii were analysed. The results showed that the levels of lysozyme and peroxidase were very similar (from 2 to 4 U mg-1 protein). However, cathepsin B was detected of 63.32 U mg-1 protein and alkaline phosphatase was only 0.12 U mg-1 protein. Moreover, protease showed a higher percentage of activity than antiprotease. A. clarkii skin mucus showed a strong antibacterial activity against Gram-negative bacteria, particularly against Aeromonas hydrophila and Vibrio parahaemolyticus but showed no effect on Gram-positive bacteria at the tested concentrations. The bactericidal activity functioned within a short time in a distinct time- and dose-dependent manner. SEM showed that after treated with A. clarkii skin mucus, the V. parahaemolyticus cells distorted and piled together, and the filaments appeared and became into cotton-shaped or quasi-honeycomb texture to adhere cells. Meanwhile, A. clarkii skin mucus showed an apparent antiparasitic activity against C. irritans theronts with a distinct dose- and time-dependent relationship. LM and SEM observation showed that after treated with skin mucus, the theronts quickly stopped their swimming and cilia movement, cells beacme rounded, cilia shed, small bubbles formed on the surface, cell nucleolus enlarged, cytoskeleton deformed, cell membranes ruptured and cell content leaked out. Antibacterial activity was not affected by 30-90 °C heat treatment but was slightly suppressed by 100 °C. In the pH treatment groups, antibacterial activity was not affected by the moderate pH treatment of 5.0-8.0, and slightly suppressed by weak acid and weak base. Therefore, we speculated that the skin mucus of A. clarkii might be a potential source of novel antibacterial and antiparasitic components for fish or human health-related applications. This study broadened our understanding of the role of skin mucus in the innate immune system and provided a basis for the further isolation and purification of active substances.

RevDate: 2018-12-05

Fuente AL, Urcuyo RJ, GH Vega (2018)

Protists and other organisms on a minute snail periostracum.

Brazilian journal of biology = Revista brasleira de biologia pii:S1519-69842018005033101 [Epub ahead of print].

Since the foundation of the Malacological Center in 1980, Universidad Centro Americana (UCA), Managua-Nicaragua, has been monitoring and collecting the marine, terrestrial, fluvial and lake mollusk population of the country. Many specimens have been photographed by Scanning Electronic Microscope (SEM), and in one of these, observation of the hairy periostracum reveals a seemingly thriving population of minute protists in possible symbiosis with their host. Adequate magnification and comparison with previous studies allowed the determination of these hosts as diatoms, testaceous amoebae, yeast, phacus, spores and other undetermined organisms which occur in tropical forests on rocks, trees and leaves. Here illustrated are diatoms and other organisms detected for the first time on the periostracum of a tropical rainforest mollusk.

RevDate: 2018-12-05

Gil-Martínez M, López-García Á, Domínguez MT, et al (2018)

Ectomycorrhizal Fungal Communities and Their Functional Traits Mediate Plant-Soil Interactions in Trace Element Contaminated Soils.

Frontiers in plant science, 9:1682.

There is an increasing consensus that microbial communities have an important role in mediating ecosystem processes. Trait-based ecology predicts that the impact of the microbial communities on ecosystem functions will be mediated by the expression of their traits at community level. The link between the response of microbial community traits to environmental conditions and its effect on plant functioning is a gap in most current microbial ecology studies. In this study, we analyzed functional traits of ectomycorrhizal fungal species in order to understand the importance of their community assembly for the soil-plant relationships in holm oak trees (Quercus ilex subsp. ballota) growing in a gradient of exposure to anthropogenic trace element (TE) contamination after a metalliferous tailings spill. Particularly, we addressed how the ectomycorrhizal composition and morphological traits at community level mediate plant response to TE contamination and its capacity for phytoremediation. Ectomycorrhizal fungal taxonomy and functional diversity explained a high proportion of variance of tree functional traits, both in roots and leaves. Trees where ectomycorrhizal fungal communities were dominated by the abundant taxa Hebeloma cavipes and Thelephora terrestris showed a conservative root economics spectrum, while trees colonized by rare taxa presented a resource acquisition strategy. Conservative roots presented ectomycorrhizal functional traits characterized by high rhizomorphs formation and low melanization which may be driven by resource limitation. Soil-to-root transfer of TEs was explained substantially by the ectomycorrhizal fungal species composition, with the highest transfer found in trees whose roots were colonized by Hebeloma cavipes. Leaf phosphorus was related to ectomycorrhizal species composition, specifically higher leaf phosphorus was related to the root colonization by Thelephora terrestris. These findings support that ectomycorrhizal fungal community composition and their functional traits mediate plant performance in metal-contaminated soils, and have a high influence on plant capacity for phytoremediation of contaminants. The study also corroborates the overall effects of ectomycorrhizal fungi on ecosystem functioning through their mediation over the plant economics spectrum.

RevDate: 2018-12-05

Nath A, Molnár MA, Csighy A, et al (2018)

Biological Activities of Lactose-Based Prebiotics and Symbiosis with Probiotics on Controlling Osteoporosis, Blood-Lipid and Glucose Levels.

Medicina (Kaunas, Lithuania), 54(6): pii:medicina54060098.

Lactose-based prebiotics are synthesized by enzymatic- or microbial- biotransformation of lactose and have unique functional values. In this comprehensive review article, the biochemical mechanisms of controlling osteoporosis, blood-lipid, and glucose levels by lactose-based prebiotics and symbiosis with probiotics are reported along with the results of clinical investigations. Interaction between lactose-based prebiotics and probiotics reduces osteoporosis by (a) transforming insoluble inorganic salts to soluble and increasing their absorption to gut wall; (b) maintaining and protecting mineral absorption surface in the intestine; (c) increasing the expression of calcium-binding proteins in the gut wall; (d) remodeling osteoclasts and osteoblasts formation; (e) releasing bone modulating factors; and (f) degrading mineral complexing phytic acid. Lactose-based prebiotics with probiotics control lipid level in the bloodstream and tissue by (a) suppressing the expressions of lipogenic- genes and enzymes; (b) oxidizing fatty acids in muscle, liver, and adipose tissue; (c) binding cholesterol with cell membrane of probiotics and subsequent assimilation by probiotics; (d) enzymatic-transformations of bile acids; and (e) converting cholesterol to coprostanol and its defecation. Symbiosis of lactose-based prebiotics with probiotics affect plasma glucose level by (a) increasing the synthesis of gut hormones plasma peptide-YY, glucagon-like peptide-1 and glucagon-like peptide-2 from entero-endocrine L-cells; (b) altering glucose assimilation and metabolism; (c) suppressing systematic inflammation; (d) reducing oxidative stress; and (e) producing amino acids. Clinical investigations show that lactose-based prebiotic galacto-oligosaccharide improves mineral absorption and reduces hyperlipidemia. Another lactose-based prebiotic, lactulose, improves mineral absorption, and reduces hyperlipidemia and hyperglycemia. It is expected that this review article will be of benefit to food technologists and medical practitioners.

RevDate: 2018-12-04

Chen S, Shao G, Shao F, et al (2018)

[Diffusion-weighted imaging texture features in differentiation of malignant from benign nonpalpable breast lesions for patients with microcalcifications-only in mammography].

Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences, 47(4):400-404.

OBJECTIVE: To evaluate the application of MR diffusion-weighted imaging(DWI) texture features in differentiation of malignant from benign nonpalpable breast lesion for patients with microcalcifications-only in mammography.

METHODS: The clinical and MR-DWI data of 61 patients with microcalcifications, who underwent three-dimensional positioning of breast X-ray wire from October 2012 to December 2015 in Zhejiang Cancer Hospital, were retrospectively analyzed, including 38 patients with malignant lesions and 23 patients with benign lesions. Two radiologists independently drew the regions of interest (ROI) on DWI for image segmentation, and 6 histogram features and 16 grayscale symbiosis matrix (GLCM) texture features were extracted on each ROI. The random forest algorithm was applied to select the features and built the classification model. The leave-one-out cross-validation (LOOCV) was used to validate the classifier, and the performance of the classifier was evaluated by ROC curve.

RESULTS: Six features were selected, including histogram features of mean, variance, skewness, entropy, as well as contrast (0°) and correlation (45°) in GLCM. The histogram features of mean, variance, skewness and entropy were significantly different between the benign and malignant breast lesions (all P<0.05). The AUC of the model was 0.76, and the diagnostic accuracy, sensitivity and specificity were 77.05%, 84.21% and 65.21%, respectively.

CONCLUSIONS: The texture feature analysis of DWI can improve the diagnostic accuracy of differentiating benign and malignant breast nonpalpable lesions with microcalcifications-only in mammography. Histogram features of mean, variance, skewness, entropy of DWI may be used as important imaging markers.

RevDate: 2018-12-04

Hernandez AE, Claussenius-Kalman HL, Ronderos J, et al (2018)

Symbiosis, Parasitism and Bilingual Cognitive Control: A Neuroemergentist Perspective.

Frontiers in psychology, 9:2171.

Interest in the intersection between bilingualism and cognitive control and accessibility to neuroimaging methods has resulted in numerous studies with a variety of interpretations of the bilingual cognitive advantage. Neurocomputational Emergentism (or Neuroemergentism for short) is a new framework for understanding this relationship between bilingualism and cognitive control. This framework considers Emergence, in which two small elements are recombined in an interactive manner, yielding a non-linear effect. Added to this is the notion that Emergence can be captured in neural systems using computationally inspired models. This review poses that bilingualism and cognitive control, as examined through the Neuroemergentist framework, are interwoven through development and involve the non-linear growth of cognitive processing encompassing brain areas that combine and recombine, in symbiotic and parasitic ways, in order to handle more complex types of processing. The models that have sought to explain the neural substrates of bilingual cognitive differences will be discussed with a reinterpretation of the entire bilingual cognitive advantage within a Neuroemergentist framework incorporating its neural bases. It will conclude by discussing how this new Neuroemergentist approach alters our view of the effects of language experience on cognitive control. Avenues to move beyond the simple notion of a bilingual advantage or lack thereof will be proposed.

RevDate: 2018-11-30

Lopes LE, Waldis SJ, Terrell SM, et al (2018)

Vibrant symbiosis: Achieving reciprocal science outreach through biological art.

PLoS biology, 16(11):e3000061 pii:PBIOLOGY-D-18-00411 [Epub ahead of print].

Scientific outreach efforts traditionally involve formally trained scientists teaching the general public about the methods, significance, and excitement of science. We recently experimented with an alternative "symbiotic outreach" model that prioritizes building a reciprocal relationship between formally trained and "outsider" scientists to facilitate active two-way communication. Herein, we present the results of our outreach effort involving college students and adults with intellectual and developmental disabilities working together to make biological and multimedia art. By discussing the steps others can take to cultivate reciprocal outreach within their local communities, we hope to lower the barrier for widespread adoption of similar approaches and ultimately to decrease the gap between formally trained scientists and the general public.

RevDate: 2018-11-30

Tsaftaris SA, H Scharr (2018)

Sharing the Right Data Right: A Symbiosis with Machine Learning.

Trends in plant science pii:S1360-1385(18)30249-8 [Epub ahead of print].

In 2014 plant phenotyping research was not benefiting from the machine learning (ML) revolution because appropriate data were lacking. We report the success of the first open-access dataset suitable for ML in image-based plant phenotyping suitable for machine learning, fuelling a true interdisciplinary symbiosis, increased awareness, and steep performance improvements on key phenotyping tasks.

RevDate: 2018-11-29

Khasa R, Vaidya A, Vrati S, et al (2018)

Membrane trafficking RNA interference screen identifies a crucial role of the clathrin endocytic pathway and ARP2/3 complex for Japanese encephalitis virus infection in HeLa cells.

The Journal of general virology [Epub ahead of print].

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is one of the leading global causes of virus-induced encephalitis. The infectious life-cycle of viruses is heavily dependent on the host membrane trafficking network. Here, we have performed a RNA-interference-based screen using a siRNA panel targeting 136 membrane trafficking proteins to identify the key regulators of JEV infection in HeLa cells. We identified 35 proteins whose siRNA depletion restricts JEV replication by over twofold. We observe that JEV infection in HeLa cells is largely dependent on components of the clathrin-mediated endocytic (CME) pathway. Proteins involved in actin-filament-based processes, specifically CDC42 and members of the ARP2/3 complex are crucial for establishment of infection. Pharmacological pertubations of actin polymerization, a small molecule inhibitor of actin nucleation by the ARP2/3 complex - CK-548 - and the inhibitor of neural Wiskott-Aldrich syndrome proteins- Wiskostatin- inhibited JEV replication, highlighting the important role of the dynamic actin network. Other proteins involved in cargo-recognition for CME and endomembrane system organization were also validated as essential host factors for virus replication.

RevDate: 2018-11-29

Paulitsch F, Klepa MS, da Silva AR, et al (2018)

Phylogenetic diversity of rhizobia nodulating native Mimosa gymnas grown in a South Brazilian ecotone.

Molecular biology reports pii:10.1007/s11033-018-4506-z [Epub ahead of print].

Floristic surveys performed in "Campos Gerais" (Paraná, Brazil), an ecotone of Mata Atlântica and Cerrado biomes, highlights the richness and relative abundance of the family Fabaceae and point out the diversity and endemism of Mimosa spp. Our study reports the genetic diversity of rhizobia isolated from root nodules of native/endemic Mimosa gymnas Barneby in three areas of Guartelá State Park, an important conservation unit of "Campos Gerais". Soils of the sample areas were characterized as sandy, acid, poor in nutrients and organic matter. The genetic variability among the isolates was revealed by BOX-PCR genomic fingerprinting. Phylogeny based on 16S rRNA gene grouped the strains in a large cluster including Paraburkholderia nodosa and P. bannensis, while recA-gyrB phylogeny separated the strains in two groups: one including P. nodosa and the other without any described Paraburkholderia species. MLSA confirmed the separate position of this second group of strains within the genus Paraburkholderia and the nucleotide identity of the five concatened housekeeping genes was 95.9% in relation to P. nodosa BR 3437T. Phylogram based on symbiosis-essential nodC gene was in agreement with 16S rRNA analysis. Our molecular phylogenetic analysis support that Paraburkholderia are the main symbionts of native Mimosa in specific edaphic conditions found in South America and reveal the importance of endemic/native leguminous plants as reservoirs of novel rhizobial species.

RevDate: 2018-11-29

Matthews JL, Oakley CA, Lutz A, et al (2018)

Partner switching and metabolic flux in a model cnidarian-dinoflagellate symbiosis.

Proceedings. Biological sciences, 285(1892): pii:rspb.2018.2336.

Metabolite exchange is fundamental to the viability of the cnidarian-Symbiodiniaceae symbiosis and survival of coral reefs. Coral holobiont tolerance to environmental change might be achieved through changes in Symbiodiniaceae species composition, but differences in the metabolites supplied by different Symbiodiniaceae species could influence holobiont fitness. Using 13C stable-isotope labelling coupled to gas chromatography-mass spectrometry, we characterized newly fixed carbon fate in the model cnidarian Exaiptasia pallida (Aiptasia) when experimentally colonized with either native Breviolum minutum or non-native Durusdinium trenchii Relative to anemones containing B. minutum, D. trenchii-colonized hosts exhibited a 4.5-fold reduction in 13C-labelled glucose and reduced abundance and diversity of 13C-labelled carbohydrates and lipogenesis precursors, indicating symbiont species-specific modifications to carbohydrate availability and lipid storage. Mapping carbon fate also revealed significant alterations to host molecular signalling pathways. In particular, D. trenchii-colonized hosts exhibited a 40-fold reduction in 13C-labelled scyllo-inositol, a potential interpartner signalling molecule in symbiosis specificity. 13C-labelling also highlighted differential antioxidant- and ammonium-producing pathway activities, suggesting physiological responses to different symbiont species. Such differences in symbiont metabolite contribution and host utilization may limit the proliferation of stress-driven symbioses; this contributes valuable information towards future scenarios that select in favour of less-competent symbionts in response to environmental change.

RevDate: 2018-11-28

Chan CK, Rosic N, Lorenc MT, et al (2018)

A differential k-mer analysis pipeline for comparing RNA-Seq transcriptome and meta-transcriptome datasets without a reference.

Functional & integrative genomics pii:10.1007/s10142-018-0647-3 [Epub ahead of print].

Next-generation DNA sequencing technologies, such as RNA-Seq, currently dominate genome-wide gene expression studies. A standard approach to analyse this data requires mapping sequence reads to a reference and counting the number of reads which map to each gene. However, for many transcriptome studies, a suitable reference genome is unavailable, especially for meta-transcriptome studies which assay gene expression from mixed populations of organisms. Where a reference is unavailable, it is possible to generate a reference by the de novo assembly of the sequence reads. However, the high cost of generating high-coverage data for de novo assembly hinders this approach and more importantly the accurate assembly of such data is challenging, especially for meta-transcriptome data, and resulting assemblies frequently suffer from collapsed regions or chimeric sequences. As an alternative to the standard reference mapping approach, we have developed a k-mer-based analysis pipeline (DiffKAP) to identify differentially expressed reads between RNA-Seq datasets without the requirement for a reference. We compared the DiffKAP approach with the traditional Tophat/Cuffdiff method using RNA-Seq data from soybean, which has a suitable reference genome. We subsequently examined differential gene expression for a coral meta-transcriptome where no reference is available, and validated the results using qRT-PCR. We conclude that DiffKAP is an accurate method to study differential gene expression in complex meta-transcriptomes without the requirement of a reference genome.

RevDate: 2018-11-28

Gagic M, Faville MJ, Zhang W, et al (2018)

Seed Transmission of Epichloë Endophytes in Lolium perenne Is Heavily Influenced by Host Genetics.

Frontiers in plant science, 9:1580.

Vertical transmission of symbiotic Epichloë endophytes from host grasses into progeny seed is the primary mechanism by which the next generation of plants is colonized. This process is often imperfect, resulting in endophyte-free seedlings which may have poor ecological fitness if the endophyte confers protective benefits to its host. In this study, we investigated the influence of host genetics and environment on the vertical transmission of Epichloë festucae var. lolii strain AR37 in the temperate forage grass Lolium perenne. The efficiency of AR37 transmission into the seed of over 500 plant genotypes from five genetically diverse breeding populations was determined. In Populations I-III, which had undergone previous selection for high seed infection by AR37, mean transmission was 88, 93, and 92%, respectively. However, in Populations IV and V, which had not undergone previous selection, mean transmission was 69 and 70%, respectively. The transmission values, together with single-nucleotide polymorphism data obtained using genotyping-by-sequencing for each host, was used to develop a genomic prediction model for AR37 seed transmission. The predictive ability of the model was estimated at r = 0.54. While host genotype contributed greatly to differences in AR37 seed transmission, undefined environmental variables also contributed significantly to seed transmission across different years and geographic locations. There was evidence for a small host genotype-by-environment effect; however this was less pronounced than genotype or environment alone. Analysis of endophyte infection levels in parent plants within Populations I and IV revealed a loss of endophyte infection over time in Population IV only. This population also had lower average tiller infection frequencies than Population I, suggesting that AR37 failed to colonize all the daughter tillers and therefore seeds. However, we also observed that infection of seed by AR37 may fail during or after initiation of floral development from plants where all tillers remained endophyte-infected over time. While the effects of environment and host genotype on fungal endophyte transmission have been evaluated previously, this is the first study that quantifies the relative impacts of host genetics and environment on endophyte vertical transmission.

RevDate: 2018-11-28

Mohammadi-Dehcheshmeh M, Niazi A, Ebrahimi M, et al (2018)

Unified Transcriptomic Signature of Arbuscular Mycorrhiza Colonization in Roots of Medicago truncatula by Integration of Machine Learning, Promoter Analysis, and Direct Merging Meta-Analysis.

Frontiers in plant science, 9:1550.

Plant root symbiosis with Arbuscular mycorrhizal (AM) fungi improves uptake of water and mineral nutrients, improving plant development under stressful conditions. Unraveling the unified transcriptomic signature of a successful colonization provides a better understanding of symbiosis. We developed a framework for finding the transcriptomic signature of Arbuscular mycorrhiza colonization and its regulating transcription factors in roots of Medicago truncatula. Expression profiles of roots in response to AM species were collected from four separate studies and were combined by direct merging meta-analysis. Batch effect, the major concern in expression meta-analysis, was reduced by three normalization steps: Robust Multi-array Average algorithm, Z-standardization, and quartiling normalization. Then, expression profile of 33685 genes in 18 root samples of Medicago as numerical features, as well as study ID and Arbuscular mycorrhiza type as categorical features, were mined by seven models: RELIEF, UNCERTAINTY, GINI INDEX, Chi Squared, RULE, INFO GAIN, and INFO GAIN RATIO. In total, 73 genes selected by machine learning models were up-regulated in response to AM (Z-value difference > 0.5). Feature weighting models also documented that this signature is independent from study (batch) effect. The AM inoculation signature obtained was able to differentiate efficiently between AM inoculated and non-inoculated samples. The AP2 domain class transcription factor, GRAS family transcription factors, and cyclin-dependent kinase were among the highly expressed meta-genes identified in the signature. We found high correspondence between the AM colonization signature obtained in this study and independent RNA-seq experiments on AM colonization, validating the repeatability of the colonization signature. Promoter analysis of upregulated genes in the transcriptomic signature led to the key regulators of AM colonization, including the essential transcription factors for endosymbiosis establishment and development such as NF-YA factors. The approach developed in this study offers three distinct novel features: (I) it improves direct merging meta-analysis by integrating supervised machine learning models and normalization steps to reduce study-specific batch effects; (II) seven attribute weighting models assessed the suitability of each gene for the transcriptomic signature which contributes to robustness of the signature (III) the approach is justifiable, easy to apply, and useful in practice. Our integrative framework of meta-analysis, promoter analysis, and machine learning provides a foundation to reveal the transcriptomic signature and regulatory circuits governing Arbuscular mycorrhizal symbiosis and is transferable to the other biological settings.

RevDate: 2018-11-29

Bauça JM (2018)

Reflections on the Mentor-Mentee Relationship: A Symbiosis.

EJIFCC, 29(3):230-233.

RevDate: 2018-11-27

Seró R, Núñez N, Núñez O, et al (2018)

Modified distribution in the polyphenolic profile of rosemary leaves induced by plant inoculation with an arbuscular mycorrhizal fungus.

Journal of the science of food and agriculture [Epub ahead of print].

BACKGROUND: Rosemary forms an arbuscular mycorrhizal (AM) symbiosis with a group of soilborne fungi belonging to the phylum Glomeromycota, which can modify the plant metabolome responsible for the antioxidant capacity and other health beneficial properties of Rosemary.

RESULTS: The effect of inoculating rosemary plants with an AM fungus on their growth via their polyphenolic fingerprinting was evaluated after analyzing leaf extracts from non-inoculated and inoculated rosemary plants by ultra-high performance liquid chromatography-high resolution mass spectrometry. . Plant growth parameters indicated that mycorrhizal inoculation significantly increased plant height and biomass. Chemical modifications in the plant polyphenolic profile distribution were found after a principal components analysis (PCA) loading plots study. Four compounds hosting strong antioxidant properties: ferulic acid, asiatic acid, carnosol, and vanillin were related to mycorrhizal rosemary plants while caffeic and chlorogenic acids had a higher influence in non-mycorrhizal plants.

CONCLUSION: Mycorrhization was found to stimulate growth in order to obtain a higher biomass of plant leaves in short time and avoiding chemical fertilization, while analytical results demonstrate that there is an alteration in the distribution of polyphenols in plants colonized by the symbiotic fungus, which can be related to an improvement in nutritional properties with future industrial significance. This article is protected by copyright. All rights reserved.

RevDate: 2018-11-27

Anheyer D, Kern C, Dobos G, et al (2018)

"I think you can achieve quite a lot if all of the staff stands behind it"-A qualitative study about the experience, knowledge and application of complementary therapies and integrative medicine in pediatrics.

Complementary therapies in medicine, 41:186-191.

BACKGROUND: In the United States there is an increasing use of complementary and alternative medicine (CAM) as well as integrative medicine (IM) in pediatrics. This study investigates the extent of knowledge and practical application of and attitudes towards the use and integration of CAM/IM therapies in two German pediatric clinics.

METHODS: A semi-standardized qualitative interview study was conducted in a rural children's hospital in Bavaria and in a children's clinic in the metropolitan area of Ruhr. Sixteen employees (7 nurses, 9 medical doctors, 68.8% female), who had volunteered through a local contact, were questioned during their shift on CAM/IM therapies. The data collected were analyzed with MAXQDA 12 using a qualitative technique for content analysis (by Mayring).

RESULTS: On average all respondents had little to superficial knowledge about the possibilities or evidence base of the therapies concerned, but did believe that CAM/IM could be an enhancement. In addition, many took interest in learning more about CAM/IM medical options. Nurses desired more practical and theoretical knowledge; while medical doctors focused on standardization and evidence base. All of them agreed that self-care strategies could enhance parental independence when treating symptoms of minor illnesses. They further agreed, that a symbiosis of conventional medicine and CAM/IM has great potential for patients and employees. It was stated that training of staff would be indispensable in order to implement standardized procedures.

CONCLUSIONS: There is great potential and interest in CAM/IM among pediatric care employees. Regardless of the challenges, this investigation did find that implementing CAM/IM might be a promising extension to the daily care routine.

RevDate: 2018-11-27

Almendras K, García J, Carú M, et al (2018)

Nitrogen-Fixing Bacteria Associated with Peltigera Cyanolichens and Cladonia Chlorolichens.

Molecules (Basel, Switzerland), 23(12): pii:molecules23123077.

Lichens have been extensively studied and described; however, recent evidence suggests that members of the bacterial community associated with them could contribute new functions to the symbiotic interaction. In this work, we compare the nitrogen-fixing guild associated with bipartite terricolous lichens with different types of photobiont: Peltigera cyanolichens and Cladonia chlorolichens. Since cyanobacteria contribute nitrogen to the symbiosis, we propose that chlorolichens have more diverse bacteria with the ability to fix nitrogen compared to cyanolichens. In addition, since part of these bacteria could be recruited from the substrate where lichens grow, we propose that thalli and substrates share some bacteria in common. The structure of the nitrogen-fixing guild in the lichen and substrate bacterial communities of both lichens was determined by terminal restriction fragment length polymorphism (TRFLP) of the nifH gene. Multivariate analyses showed that the nitrogen-fixing bacteria associated with both types of lichen were distinguishable from those present in their substrates. Likewise, the structure of the nitrogen-fixing bacteria present in the cyanolichens was different from that of chlorolichens. Finally, the diversity of this bacterial guild calculated using the Shannon index confirms the hypothesis that chlorolichens have a higher diversity of nitrogen-fixing bacteria than cyanolichens.

RevDate: 2018-11-26

Valdés-López O, Jayaraman D, Maeda J, et al (2018)

A Novel Positive Regulator of the Early Stages of the Root Nodule Symbiosis Identified by Phosphoproteomics.

Plant & cell physiology pii:5201344 [Epub ahead of print].

Signals and signaling pathways underlying the symbiosis between legumes and rhizobia have been studied extensively over the past decades. In a previous phosphoproteomic study on the Medicago truncatula - Sinorhizobium meliloti symbiosis, we identified plant proteins that are differentially phosphorylated upon the perception of rhizobial signals, called Nod factors. In this study, we provide experimental evidence that one of these proteins, Early Phosphorylated Protein 1 (EPP1), is required for the initiation of this symbiosis. Upon inoculation with rhizobia, MtEPP1 expression was induced in curled root hairs. Down-regulation of MtEPP1 in M. truncatula roots almost abolished calcium spiking, reduced the expression of essential symbiosis-related genes (MtNIN, MtNF-YB1, MtERN1, and MtENOD40), and strongly decreased nodule development. Phylogenetic analyses revealed that orthologs of MtEPP1 are present in legumes and specifically in plant species able to host arbuscular mycorrhizal fungi, suggesting a possible role in this association too. Short chitin oligomers induced the phosphorylation of MtEPP1 like Nod factors. However, the down-regulation of MtEPP1 affected the colonization of M. truncatula roots by arbuscular mycorrhizal fungi only moderately. Altogether, these findings indicate that MtEPP1 is essential for the establishment of the legume-rhizobia symbiosis but might plays a limited role in the arbuscular mycorrhizal symbiosis.

RevDate: 2018-11-26

Alonso D, Mancini MV, Damiani C, et al (2018)

Genome reduction in the mosquito symbiont Asaia.

Genome biology and evolution pii:5201038 [Epub ahead of print].

Symbiosis is now recognized as a driving force in evolution, a role that finds its ultimate expression in the variety of associations bonding insects with microbial symbionts. These associations have contributed to the evolutionary success of insects, with the hosts acquiring the capacity to exploit novel ecological niches, and the symbionts passing from facultative associations to obligate, mutualistic symbioses. In bacterial symbiont of insects, the transition from the free-living life style to mutualistic symbiosis often resulted in a reduction in the genome size, with the generation of the smallest bacterial genomes thus far described. Here we show that the process of genome reduction is still occurring in Asaia, a group of bacterial symbionts associated with a variety of insects. Indeed, comparative genomics of Asaia isolated from different mosquito species revealed a substantial genome size and gene content reduction in Asaia from Anopheles darlingi, a South-American malaria vector. We thus propose Asaia as a novel model to study genome reduction dynamics, within a single bacterial taxon, evolving in a common biological niche.

RevDate: 2018-11-30

Yang T, Cheng H, Wang H, et al (2018)

Comparative study of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in corals, surrounding sediments and surface water at the Dazhou Island, China.

Chemosphere, 218:157-168 pii:S0045-6535(18)32170-2 [Epub ahead of print].

This study investigated polycyclic aromatic hydrocarbons (PAHs) content in corals (Acropora sp.), surficial sediments, and surface seawater, and heavy metals (HMs) contents in corals and sediments from Dazhou Island, Hainan, China. Concentrations of PAHs in seawater and sediment seasonally ranged from 191.5 ng L-1 to 587.7 ng L-1, and from 37.9 ng g-1 to 233 ng g-1, while levels in corals were higher (185.2-545.0 ng g-1) compared to those found in sediments, demonstrating bioaccumulation of PAHs by corals. A similar seasonally variation of PAHs was observed in water/sediments and corals, and the proportions of low molecular weight PAHs (LPAHs) in seawater and corals were higher. Pyrolytic and petrogenic contaminations were identified to be the main sources of PAHs. Lower HMs concentrations were detected in corals (9.8-39.4 μg g-1) than in sediments (65.0-83.3 μg g-1), but HMs bioaccumulation still occurs in corals. Higher concentrations of HMs in sediment and corals were detected in March and December, especially Mn and Zn. Application of an enrichment factor showed that Cu in corals was delivered from non-crustal materials, and anthropogenic inputs were possibly the main sources. According to Biota Sediment Accumulation Factor, corals could strongly bioaccumulate LPAHs and Cd, and PAHs at a higher (p < 0.05) rate than HMs. There was a lack of correlation between the accumulation of PAHs and HMs in corals based on the cluster analysis. Dual hierarchical clustering analysis result revealed that feeding, instead of symbiosis, might be the main process responsible for the bioaccumulation of PAHs and HMs.

RevDate: 2018-11-27

Doudoumis V, Augustinos A, Saridaki A, et al (2018)

Different laboratory populations similar bacterial profile? The case of Glossina palpalis gambiensis.

BMC microbiology, 18(Suppl 1):148 pii:10.1186/s12866-018-1290-9.

BACKGROUND: Microbiota plays an important role in the biology, ecology and evolution of insects including tsetse flies. The bacterial profile of 3 Glossina palpalis gambiensis laboratory colonies was examined using 16S rRNA gene amplicon sequencing to evaluate the dynamics of the bacterial diversity within and between each G. p. gambiensis colony.

RESULTS: The three G. p. gambiensis laboratory colonies displayed similar bacterial diversity indices and OTU distribution. Larval guts displayed a higher diversity when compared with the gastrointestinal tract of adults while no statistically significant differences were observed between testes and ovaries. Wigglesworthia and Sodalis were the most dominant taxa. In more detail, the gastrointestinal tract of adults was more enriched by Wigglesworthia while Sodalis were prominent in gonads. Interestingly, in larval guts a balanced co-existence between Wigglesworthia and Sodalis was observed. Sequences assigned to Wolbachia, Propionibacterium, and Providencia were also detected but to a much lesser degree. Clustering analysis indicated that the bacterial profile in G. p. gambiensis exhibits tissue tropism, hence distinguishing the gut bacterial profile from that present in reproductive organs.

CONCLUSIONS: Our results indicated that age, gender and the origin of the laboratory colonies did not significantly influence the formation of the bacterial profile, once these populations were kept under the same rearing conditions. Within the laboratory populations a tissue tropism was observed between the gut and gonadal bacterial profile.

RevDate: 2018-11-27

Augustinos AA, Meki IK, Demirbas-Uzel G, et al (2018)

Nuclear and Wolbachia-based multimarker approach for the rapid and accurate identification of tsetse species.

BMC microbiology, 18(Suppl 1):147 pii:10.1186/s12866-018-1295-4.

BACKGROUND: Tsetse flies (Diptera: Glossinidae) are solely responsible for the transmission of African trypanosomes, causative agents of sleeping sickness in humans and nagana in livestock. Due to the lack of efficient vaccines and the emergence of drug resistance, vector control approaches such as the sterile insect technique (SIT), remain the most effective way to control disease. SIT is a species-specific approach and therefore requires accurate identification of natural pest populations at the species level. However, the presence of morphologically similar species (species complexes and sub-species) in tsetse flies challenges the successful implementation of SIT-based population control.

RESULTS: In this study, we evaluate different molecular tools that can be applied for the delimitation of different Glossina species using tsetse samples derived from laboratory colonies, natural populations and museum specimens. The use of mitochondrial markers, nuclear markers (including internal transcribed spacer 1 (ITS1) and different microsatellites), and bacterial symbiotic markers (Wolbachia infection status) in combination with relatively inexpensive techniques such as PCR, agarose gel electrophoresis, and to some extent sequencing provided a rapid, cost effective, and accurate identification of several tsetse species.

CONCLUSIONS: The effectiveness of SIT benefits from the fine resolution of species limits in nature. The present study supports the quick identification of large samples using simple and cost effective universalized protocols, which can be easily applied by countries/laboratories with limited resources and expertise.

RevDate: 2018-11-27

Engl T, Michalkova V, Weiss BL, et al (2018)

Effect of antibiotic treatment and gamma-irradiation on cuticular hydrocarbon profiles and mate choice in tsetse flies (Glossina m. morsitans).

BMC microbiology, 18(Suppl 1):145 pii:10.1186/s12866-018-1292-7.

BACKGROUND: Symbiotic microbes represent a driving force of evolutionary innovation by conferring novel ecological traits to their hosts. Many insects are associated with microbial symbionts that contribute to their host's nutrition, digestion, detoxification, reproduction, immune homeostasis, and defense. In addition, recent studies suggest a microbial involvement in chemical communication and mating behavior, which can ultimately impact reproductive isolation and, hence, speciation. Here we investigated whether a disruption of the microbiota through antibiotic treatment or irradiation affects cuticular hydrocarbon profiles, and possibly mate choice behavior in the tsetse fly, Glossina morsitans morsitans. Four independent experiments that differentially knock down the multiple bacterial symbionts of tsetse flies were conducted by subjecting tsetse flies to ampicillin, tetracycline, or gamma-irradiation and analyzing their cuticular hydrocarbon profiles in comparison to untreated controls by gas chromatography - mass spectrometry. In two of the antibiotic experiments, flies were mass-reared, while individual rearing was done for the third experiment to avoid possible chemical cross-contamination between individual flies.

RESULTS: All three antibiotic experiments yielded significant effects of antibiotic treatment (particularly tetracycline) on cuticular hydrocarbon profiles in both female and male G. m. morsitans, while irradiation itself had no effect on the CHC profiles. Importantly, tetracycline treatment reduced relative amounts of 15,19,23-trimethyl-heptatriacontane, a known compound of the female contact sex pheromone, in two of the three experiments, suggesting a possible implication of microbiota disturbance on mate choice decisions. Concordantly, both female and male flies preferred non-treated over tetracycline-treated flies in direct choice assays.

CONCLUSIONS: While we cannot exclude the possibility that antibiotic treatment had a directly detrimental effect on fly vigor as we are unable to recolonize antibiotic treated flies with individual symbiont taxa, our results are consistent with an effect of the microbiota, particularly the obligate nutritional endosymbiont Wigglesworthia, on CHC profiles and mate choice behavior. These findings highlight the importance of considering host-microbiota interactions when studying chemical communication and mate choice in insects.

RevDate: 2018-11-28

Zaidman-Rémy A, Vigneron A, Weiss BL, et al (2018)

What can a weevil teach a fly, and reciprocally? Interaction of host immune systems with endosymbionts in Glossina and Sitophilus.

BMC microbiology, 18(Suppl 1):150 pii:10.1186/s12866-018-1278-5.

The tsetse fly (Glossina genus) is the main vector of African trypanosomes, which are protozoan parasites that cause human and animal African trypanosomiases in Sub-Saharan Africa. In the frame of the IAEA/FAO program 'Enhancing Vector Refractoriness to Trypanosome Infection', in addition to the tsetse, the cereal weevil Sitophilus has been introduced as a comparative system with regards to immune interactions with endosymbionts. The cereal weevil is an agricultural pest that destroys a significant proportion of cereal stocks worldwide. Tsetse flies are associated with three symbiotic bacteria, the multifunctional obligate Wigglesworthia glossinidia, the facultative commensal Sodalis glossinidius and the parasitic Wolbachia. Cereal weevils house an obligatory nutritional symbiosis with the bacterium Sodalis pierantonius, and occasionally Wolbachia. Studying insect host-symbiont interactions is highly relevant both for understanding the evolution of symbiosis and for envisioning novel pest control strategies. In both insects, the long co-evolution between host and endosymbiont has led to a stringent integration of the host-bacteria partnership. These associations were facilitated by the development of specialized host traits, including symbiont-housing cells called bacteriocytes and specific immune features that enable both tolerance and control of the bacteria. In this review, we compare the tsetse and weevil model systems and compile the latest research findings regarding their biological and ecological similarities, how the immune system controls endosymbiont load and location, and how host-symbiont interactions impact developmental features including cuticle synthesis and immune system maturation. We focus mainly on the interactions between the obligate symbionts and their host's immune systems, a central theme in both model systems. Finally, we highlight how parallel studies on cereal weevils and tsetse flies led to mutual discoveries and stimulated research on each model, creating a pivotal example of scientific improvement through comparison between relatively distant models.

RevDate: 2018-11-25

Libault M (2018)

Transcriptional Reprogramming of Legume Genomes: Perspective and Challenges Associated With Single-Cell and Single Cell-Type Approaches During Nodule Development.

Frontiers in plant science, 9:1600.

Transcriptomic approaches revealed thousands of genes differentially or specifically expressed during nodulation, a biological process resulting from the symbiosis between leguminous plant roots and rhizobia, atmospheric nitrogen-fixing symbiotic bacteria. Ultimately, nodulation will lead to the development of a new root organ, the nodule. Through functional genomic studies, plant transcriptomes have been used by scientists to reveal plant genes potentially controlling nodulation. However, it is important to acknowledge that the physiology, transcriptomic programs, and biochemical properties of the plant cells involved in nodulation are continuously regulated. They also differ between the different cell-types composing the nodules. To generate a more accurate picture of the transcriptome, epigenome, proteome, and metabolome of the cells infected by rhizobia and cells composing the nodule, there is a need to implement plant single-cell and single cell-types strategies and methods. Accessing such information would allow a better understanding of the infection of plant cells by rhizobia and will help understanding the complex interactions existing between rhizobia and the plant cells. In this mini-review, we are reporting the current knowledge on legume nodulation gained by plant scientists at the level of single cell-types, and provide perspectives on single cell/single cell-type approaches when applied to legume nodulation.

RevDate: 2018-11-27

Pollock FJ, McMinds R, Smith S, et al (2018)

Coral-associated bacteria demonstrate phylosymbiosis and cophylogeny.

Nature communications, 9(1):4921 pii:10.1038/s41467-018-07275-x.

Scleractinian corals' microbial symbionts influence host health, yet how coral microbiomes assembled over evolution is not well understood. We survey bacterial and archaeal communities in phylogenetically diverse Australian corals representing more than 425 million years of diversification. We show that coral microbiomes are anatomically compartmentalized in both modern microbial ecology and evolutionary assembly. Coral mucus, tissue, and skeleton microbiomes differ in microbial community composition, richness, and response to host vs. environmental drivers. We also find evidence of coral-microbe phylosymbiosis, in which coral microbiome composition and richness reflect coral phylogeny. Surprisingly, the coral skeleton represents the most biodiverse coral microbiome, and also shows the strongest evidence of phylosymbiosis. Interactions between bacterial and coral phylogeny significantly influence the abundance of four groups of bacteria-including Endozoicomonas-like bacteria, which divide into host-generalist and host-specific subclades. Together these results trace microbial symbiosis across anatomy during the evolution of a basal animal lineage.

RevDate: 2018-11-22

Antonopoulos CN, CD Liapis (2018)

Aneurysms and Diabetes Mellitus: A Strange Symbiosis?.

Cardiology, 141(2):123-124 pii:000490925 [Epub ahead of print].

RevDate: 2018-11-22

Hubert J, Nesvorna M, Kopecky J, et al (2018)

Population and Culture Age Influence the Microbiome Profiles of House Dust Mites.

Microbial ecology pii:10.1007/s00248-018-1294-x [Epub ahead of print].

Interactions with microorganisms might enable house dust mites (HDMs) to derive nutrients from difficult-to-digest structural proteins and to flourish in human houses. We tested this hypothesis by investigating the effects of changes in the mite culture growth and population of two HDM species on HDM microbiome composition and fitness. Growing cultures of laboratory and industrial allergen-producing populations of Dermatophagoides farinae (DFL and DFT, respectively) and Dermatophagoides pteronyssinus (DPL and DPT, respectively) were sampled at four time points. The symbiotic microorganisms of the mites were characterized by DNA barcode sequencing and quantified by qPCR using universal/specific primers. The population growth of mites and nutrient contents of mite bodies were measured and correlated with the changes in bacteria in the HDM microbiome. The results showed that both the population and culture age significantly influenced the microbiome profiles. Cardinium formed 93% and 32% of the total sequences of the DFL and DFT bacterial microbiomes, respectively, but this bacterial species was less abundant in the DPL and DPT microbiomes. Staphylococcus abundance was positively correlated with increased glycogen contents in the bodies of mites, and increased abundances of Aspergillus, Candida, and Kocuria were correlated with increased lipid contents in the bodies of mites. The xerophilic fungus Wallemia accounted for 39% of the fungal sequences in the DPL microbiome, but its abundance was low in the DPT, DFL, and DFT microbiomes. With respect to the mite culture age, we made three important observations: the mite population growth from young cultures was 5-8-fold higher than that from old cultures; specimens from old cultures had greater abundances of fungi and bacteria in their bodies; and yeasts predominated in the gut contents of specimens from young cultures, whereas filamentous mycelium prevailed in specimens from old cultures. Our results are consistent with the hypothesis that mites derive nutrients through associations with microorganisms.

RevDate: 2018-11-22

Mao M, Yang X, GM Bennett (2018)

Evolution of host support for two ancient bacterial symbionts with differentially degraded genomes in a leafhopper host.

Proceedings of the National Academy of Sciences of the United States of America pii:1811932115 [Epub ahead of print].

Plant sap-feeding insects (Hemiptera) rely on bacterial symbionts for nutrition absent in their diets. These bacteria experience extreme genome reduction and require genetic resources from their hosts, particularly for basic cellular processes other than nutrition synthesis. The host-derived mechanisms that complete these processes have remained poorly understood. It is also unclear how hosts meet the distinct needs of multiple bacterial partners with differentially degraded genomes. To address these questions, we investigated the cell-specific gene-expression patterns in the symbiotic organs of the aster leafhopper (ALF), Macrosteles quadrilineatus (Cicadellidae). ALF harbors two intracellular symbionts that have two of the smallest known bacterial genomes: Nasuia (112 kb) and Sulcia (190 kb). Symbionts are segregated into distinct host cell types (bacteriocytes) and vary widely in their basic cellular capabilities. ALF differentially expresses thousands of genes between the bacteriocyte types to meet the functional needs of each symbiont, including the provisioning of metabolites and support of cellular processes. For example, the host highly expresses genes in the bacteriocytes that likely complement gene losses in nucleic acid synthesis, DNA repair mechanisms, transcription, and translation. Such genes are required to function in the bacterial cytosol. Many host genes comprising these support mechanisms are derived from the evolution of novel functional traits via horizontally transferred genes, reassigned mitochondrial support genes, and gene duplications with bacteriocyte-specific expression. Comparison across other hemipteran lineages reveals that hosts generally support the incomplete symbiont cellular processes, but the origins of these support mechanisms are generally specific to the host-symbiont system.

RevDate: 2018-11-27

Toju H, Sato H, Yamamoto S, et al (2018)

Structural diversity across arbuscular mycorrhizal, ectomycorrhizal, and endophytic plant-fungus networks.

BMC plant biology, 18(1):292 pii:10.1186/s12870-018-1500-5.

BACKGROUND: Below-ground linkage between plant and fungal communities is one of the major drivers of terrestrial ecosystem dynamics. However, we still have limited knowledge of how such plant-fungus associations vary in their community-scale properties depending on fungal functional groups and geographic locations.

METHODS: By compiling a high-throughput sequencing dataset of root-associated fungi in eight forests along the Japanese Archipelago, we performed a comparative analysis of arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic associations across a latitudinal gradient from cool-temperate to subtropical regions.

RESULTS: In most of the plant-fungus networks analyzed, host-symbiont associations were significantly specialized but lacked "nested" architecture, which has been commonly reported in plant-pollinator and plant-seed disperser networks. In particular, the entire networks involving all functional groups of plants and fungi and partial networks consisting of ectomycorrhizal plant and fungal species/taxa displayed "anti-nested" architecture (i.e., negative nestedness scores) in many of the forests examined. Our data also suggested that geographic factors affected the organization of plant-fungus network structure. For example, the southernmost subtropical site analyzed in this study displayed lower network-level specificity of host-symbiont associations and higher (but still low) nestedness than northern localities.

CONCLUSIONS: Our comparative analyses suggest that arbuscular mycorrhizal, ectomycorrhizal, and saprotrophic/endophytic plant-fungus associations often lack nested network architecture, while those associations can vary, to some extent, in their community-scale properties along a latitudinal gradient. Overall, this study provides a basis for future studies that will examine how different types of plant-fungus associations collectively structure terrestrial ecosystems.

RevDate: 2018-11-21

Hernández-López A, Díaz M, Rodríguez-López J, et al (2018)

The overexpression of Bax inhibitor-1 in common bean roots highlights its dual role in the legume-rhizobia symbiosis.

Journal of experimental botany pii:5194635 [Epub ahead of print].

Bax-inhibitor 1 (BI-1) is a cell death suppressor conserved in all eukaryotes that modulates cell death in response to abiotic stress and pathogen attack in plants. Thus far nothing is known about its role in the establishment of symbiotic interactions. Here, we demonstrate the functional relevance of an Arabidopsisthaliana BI-1 homolog (PvBI-1a) to symbiosis between the common bean (Phaseolus vulgaris) and Rhizobium tropici. We show that the PvBI-1a expression changes observed during early symbiosis resemble those of some defence-response related proteins. By using gain- and loss-of-function approaches, we demonstrate that the overexpression of PvBI-1a in the roots of common bean increases the number of rhizobial infection events (and therefore the final number of nodules per root), but induces the premature death of nodule cells, thus affecting their nitrogen fixation efficiency. Nodule morphological alterations are known to be associated with changes in the expression of genes tied to defence, autophagy, and vesicular trafficking. Results obtained in the present work suggest that BI-1 has a dual role in the regulation of programmed cell death during symbiosis, thus extending our understanding about its critical function in the modulation of host immunity while responding to by beneficial microbes.

RevDate: 2018-11-21

Song YY, Xia M, Lin YB, et al (2018)

[Colonization with arbuscular mycorrhizal fungus Funneliformis mosseae enhanced the responses of tomato plants to mechanical wounding].

Ying yong sheng tai xue bao = The journal of applied ecology, 29(11):3811-3818.

Insect herbivore feeding causes mechanical damage to plants, which can activate plant defense responses. Whether symbiosis with beneficial microorganisms can enhance the responses of plants to mechanical damage is of importance for plant anti-herbivore resistance. In this study, defense responses of tomato (Lycopersicon esculentum) plants to mechanical wounding was investigated after the tomato roots being infected by arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae. The results showed that in response to leaf mechanical wounding, the activities of phenylalanine ammonia-lyase (PAL), superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO) and catalase (CAT) in the leaves of tomato pre-inoculated with AMF (FD), as well as transcript levels of genes encoding phenylalanine ammonia lyase (PAL) and β-1,3-glucanase (PR2) in the leaves and roots were significantly higher in relative to sole mechanical wounding (D), sole mycorrhizal inoculation (F), and control without mechanical wounding and mycorrhizal inoculation (CK). Although the activities of protective enzyme and transcript levels of the two defense-related genes were induced in the plants of sole mechanical wounding (D) and sole mycorrhizal inoculation (F), the induction was faster and stronger in the plants with leaf mechanical wounding and mycorrhizal pre-inoculation (FD). Our findings indicated that arbuscular mycorrhizal colonization could prime quicker and stronger defense responses of tomato plants to mechanical damage.

RevDate: 2018-11-23

Arora G, Chaudhary D, Kidwai S, et al (2018)

CitE Enzymes Are Essential for Mycobacterium tuberculosis to Establish Infection in Macrophages and Guinea Pigs.

Frontiers in cellular and infection microbiology, 8:385.

Bacterial citrate lyase activity has been demonstrated in various eukaryotes, bacteria and archaea, underscoring their importance in energy metabolism of the cell. While the bacterial citrate lyase comprises of three different subunits, M. tuberculosis genome lacks CitD and CitF subunits of citrate lyase complex but encodes for 2 homologs of CitE subunits, Rv2498c and Rv3075c. Using temperature sensitive mycobacteriophages, we were able to generate both single and double citE mutant strains of M. tuberculosis. The survival experiments revealed increased susceptibility of the double mutant strain to oxidative stress in comparison to the parental strain. Also, simultaneous deletion of both citE1 and citE2 in M. tuberculosis genome resulted in impairment of intracellular replication in macrophages. The double mutant strain displayed reduced growth in lungs and spleens of guinea pigs. This is the first study demonstrating that M. tuberculosis critically requires CitE subunits of citrate lyase for pathogenesis. Taken together, these findings position these enzymes as potential targets for development of anti-tubercular small molecules.

RevDate: 2018-11-23

Grosche C, Genau AC, SA Rensing (2018)

Evolution of the Symbiosis-Specific GRAS Regulatory Network in Bryophytes.

Frontiers in plant science, 9:1621.

Arbuscular mycorrhiza is one of the most common plant symbiotic interactions observed today. Due to their nearly ubiquitous occurrence and their beneficial impact on both partners it was suggested that this mutualistic interaction was crucial for plants to colonize the terrestrial habitat approximately 500 Ma ago. On the plant side the association is established via the common symbiotic pathway (CSP). This pathway allows the recognition of the fungal symbiotic partner, subsequent signaling to the nucleus, and initiation of the symbiotic program with respect to specific gene expression and cellular re-organization. The downstream part of the CSP is a regulatory network that coordinates the transcription of genes necessary to establish the symbiosis, comprising multiple GRAS transcription factors (TFs). These regulate their own expression as an intricate transcriptional network. Deduced from non-host genome data the loss of genes encoding CSP components coincides with the loss of the interaction itself. Here, we analyzed bryophyte species with special emphasis on the moss Physcomitrella patens, supposed to be a non-host, for the composition of the GRAS regulatory network components. We show lineage specific losses and expansions of several of these factors in bryophytes, potentially coinciding with the proposed host/non-host status of the lineages. We evaluate losses and expansions and infer clade-specific evolution of GRAS TFs.

RevDate: 2018-11-23

Chun SC, Paramasivan M, M Chandrasekaran (2018)

Proline Accumulation Influenced by Osmotic Stress in Arbuscular Mycorrhizal Symbiotic Plants.

Frontiers in microbiology, 9:2525.

Salinity and drought are the major osmotic stress limitations that affect plant growth and crop yield in agriculture worldwide. The alternative response mediated by plants in response to salinity and drought are principally proline accumulation which regulates stress combat strategies owing to sustainable production in the realm of agricultural production even under severe stress. Symbiotic and soil associated arbuscular mycorrhizal fungi (AMF) are regarded as efficient biofertilizers in several crops under these stresses. Summarily AMF is renowned for effective scavengers of free radicals in soil thereby increasing soil parameters optimal for plant growth. AMF contribute to augment host plant tolerance to stress specifically salinity and drought. Mycorrhizal colonization positively regulates root uptake of available nutrients and enhance growth even when bestowed by water constraints which has contributory roles due to proline accumulation providing several intriguing researches on AMF symbiosis pertaining to plant productivity and yield. Mycorrhizal plants and their non-mycorrhizal counterparts show varied expression pattern regarding proline amass. Hence, the precise role of proline with respect to stress tolerance and equivocal mechanisms involved in evasion of osmotic stress has not been extensively reviewed earlier. Further molecular forecasting in this arena is still an underexploited research field. This review comprehensively addresses the observable facts pertaining to proline accumulation upon AMF association and adherence relevant to stress tolerance and host plant efficiency and efficacy.

RevDate: 2018-11-23

Brown AMV, Wasala SK, Howe DK, et al (2018)

Comparative Genomics of Wolbachia-Cardinium Dual Endosymbiosis in a Plant-Parasitic Nematode.

Frontiers in microbiology, 9:2482.

Wolbachia and Cardinium are among the most important and widespread of all endosymbionts, occurring in nematodes and more than half of insect and arachnid species, sometimes as coinfections. These symbionts are of significant interest as potential biocontrol agents due to their abilities to cause major effects on host biology and reproduction through cytoplasmic incompatibility, sex ratio distortion, or obligate mutualism. The ecological and metabolic effects of coinfections are not well understood. This study examined a Wolbachia-Cardinium coinfection in the plant-parasitic nematode (PPN), Pratylenchus penetrans, producing the first detailed study of such a coinfection using fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and comparative genomic analysis. Results from FISH and single-nematode PCR showed 123/127 individuals in a focal population carried Cardinium (denoted strain cPpe), and 48% were coinfected with Wolbachia strain wPpe. Both endosymbionts showed dispersed tissue distribution with highest densities in the anterior intestinal walls and gonads. Phylogenomic analyses confirmed an early place of cPpe and long distance from a sister strain in another PPN, Heterodera glycines, supporting a long history of both Cardinium and Wolbachia in PPNs. The genome of cPpe was 1.36 Mbp with 35.8% GC content, 1,131 predicted genes, 41% having no known function, and missing biotin and lipoate synthetic capacity and a plasmid present in other strains, despite having a slightly larger genome compared to other sequenced Cardinium. The larger genome revealed expansions of gene families likely involved in host-cellular interactions. More than 2% of the genes of cPpe and wPpe were identified as candidate horizontally transferred genes, with some of these from eukaryotes, including nematodes. A model of the possible Wolbachia-Cardinium interaction is proposed with possible complementation in function for pathways such as methionine and fatty acid biosynthesis and biotin transport.

RevDate: 2018-11-21

Rubio AO, Kupferberg SJ, Vargas García V, et al (2018)

Widespread occurrence of the antifungal cutaneous bacterium Janthinobacterium lividum on Andean water frogs threatened by fungal disease.

Diseases of aquatic organisms, 131(3):233-238.

Amphibian diversity has declined due to the infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). Coexistence between amphibian hosts and this pathogen in some locations is attributed to the presence of the cutaneous bacterium Janthinobacterium lividum (Jliv). This microbe inhibits the growth of Bd on the host, reduces morbidity, and improves survival. Andean water frogs in the genus Telmatobius seem to be particularly vulnerable to the disease yet populations of T. intermedius and T. marmoratus persist in southern and central Peru. We investigated the presence of Jliv on these 2 frog species and assessed the relationship of Jliv presence with prevalence and intensity of Bd infection. By sampling 125 frogs from 7 streams (3323-3950 m a.s.l.) and 27 from a city market, we found spatial variation in the mutualism among populations (range 0-40% proportion of Jliv-positives). Overall, 57% of frogs were infected with Bd, 12.5% of frogs hosted both Jliv and Bd, while 7.2% hosted just Jliv. We found that the probability of an individual being infected with Bd was independent of the presence of Jliv; however, we did detect a protective effect of Jliv with respect to intensity of infection. The extent of Jliv distribution in the high Andes stands in stark contrast to the rarity of Jliv on frogs in lower elevation cloud forest biomes.

RevDate: 2018-11-27

Salducci MD, Folzer H, Issartel J, et al (2018)

How can a rare protected plant cope with the metal and metalloid soil pollution resulting from past industrial activities? Phytometabolites, antioxidant activities and root symbiosis involved in the metal tolerance of Astragalus tragacantha.

Chemosphere, 217:887-896 pii:S0045-6535(18)32185-4 [Epub ahead of print].

Astragalus tragacantha is a protected plant species in France that grows even in the trace metal and metalloid (TMM) polluted soils of the Calanques National Park (PNCal). Soils are mainly contaminated by lead, copper, zinc and arsenic. An ex situ experiment was conducted, firstly to determine the molecular responses and root traits involved in the TMM tolerance of this plant species by growing individuals in a soil from the surroundings of one of the brownfields of the PNCal, known as l'Escalette, where this plant species grows spontaneously. Secondly, in order to determine the plasticity of these responses, seeds were collected from three different populations, 1 at l'Escalette (polluted site), one from the Frioul archipelago (non-polluted, insular site) and one from La Seyne (non-polluted, littoral site). The results of this study confirmed the capacity of A. tragacantha to germinate and grow in TMM contaminated soils. Only moderate significant variations in chlorophyll and flavonol indices, proline content and antioxidant activities were detected between polluted and control soil conditions for all populations. The main driver for A. tragacantha TMM tolerance seemed to be its ability to be associated with root symbionts i.e. arbuscular mycorrhizal fungi and dark septate endophytes, corresponding to a nutrient-uptake strategy trait. This work provides support for the challenge of A. tragacantha conservation along the littoral of the PNCal, because increasing the number of A. tragacantha individuals would both increase vegetation cover of the polluted soils to reduce the pollution transfer and reinforce the populations of this species.

RevDate: 2018-11-30

Tinkov AA, Ajsuvakova OP, Skalnaya MG, et al (2018)

Organotins in obesity and associated metabolic disturbances.

Journal of inorganic biochemistry, 191:49-59 pii:S0162-0134(18)30466-5 [Epub ahead of print].

The objective of the present study was to review the mechanisms of organotin-induced adipogenesis, obesity, and associated metabolic disturbances. Peroxisome proliferator-activated receptor γ (PPARγ) and retinoid X receptor α (RXRα) activation is considered as the key mechanism of organotin-induced adipogenesis. Particularly, organotin exposure results in increased adipogenesis both in cell and animal models. Moreover, transgenerational inheritance of organotin-induced obese phenotype was demonstrated in vivo. At the same time, the existing data demonstrate that organotin compounds (OTCs) induces aberrant expression of PPARγ-targeted genes, resulting in altered of adipokine, glucose transporter, proinflammatory cytokines levels, and lipid and carbohydrate metabolism. The latter is generally characterized by hyperglycemia and insulin resistance. Other mechanisms involved in organotin-induced obesity may include estrogen receptor and corticosteroid signaling, altered DNA methylation, and gut dysfunction. In addition to cellular effects, organotin exposure may also affect neural circuits of appetite regulation, being characterized by neuropeptide Y (NPY) up-regulation in parallel with of pro-opiomelanocortin (POMC), Agouti-related protein (AgRP), and cocaine and amphetamine regulated transcript (CART) down-regulation in the arcuate nucleus. These changes result in increased orexigenic and reduced anorexigenic signaling, leading to increased food intake. The existing data demonstrate that organotins are potent adipogenic agents, however, no epidemiologic studies have been performed to reveal the association between organotin exposure and obesity and the existing indirect human data are contradictory.

RevDate: 2018-12-03

Yu J, Wang M, Liu B, et al (2018)

Gill symbionts of the cold-seep mussel Bathymodiolus platifrons: Composition, environmental dependency and immune control.

Fish & shellfish immunology, 86:246-252 pii:S1050-4648(18)30760-5 [Epub ahead of print].

Deep-sea Bathymodiolus mussels depend on the organic carbon supplied by symbionts inside their gills. In this study, optimized methods of quantitative real-time PCR and fluorescence in situ hybridization targeted to both mRNA and 16S rRNA were used to investigate the gill symbionts of the cold-seep mussel Bathymodiolus platifrons, including species composition, environmental dependency and immune control by the host. Our results showed that methanotrophs were the major symbiotic bacteria in the gills of B. platifrons, while thiotrophs were scarce. In the mussels freshly collected from the deep sea, methanotrophs were housed in bacteriocytes in a unique circular pattern, and a lysosome-related gene (VAMP) encoding a vesicle-associated membrane protein was expressed at a high level and presented exactly where the methanotrophs occurred. After the mussels were reared for three months in aquaria without methane supply, the abundance of methanotrophs decreased significantly and their circle-shaped distribution pattern disappeared; in addition, the expression of VAMP decreased significantly. These results suggest that the symbiosis between B. platifrons and methanotrophs is influenced by the environment and that the lysosomal system plays an important immune role in controlling the abundance of endosymbionts in host. This study provides a reliable method for investigating symbionts in deep-sea mussels and enriches the knowledge about symbionts in B. platifrons.

RevDate: 2018-11-19

Prazeres M, W Renema (2018)

Evolutionary significance of the microbial assemblages of large benthic Foraminifera.

Biological reviews of the Cambridge Philosophical Society [Epub ahead of print].

Large benthic Foraminifera (LBF) are major carbonate producers on coral reefs, and are hosts to a diverse symbiotic microbial community. During warm episodes in the geological past, these reef-building organisms expanded their geographical ranges as subtropical and tropical belts moved into higher latitudes. During these range-expansion periods, LBF were the most prolific carbonate producers on reefs, dominating shallow carbonate platforms over reef-building corals. Even though the fossil and modern distributions of groups of species that harbour different types of symbionts are known, the nature, mechanisms, and factors that influence their occurrence remain elusive. Furthermore, the presence of a diverse and persistent bacterial community has only recently gained attention. We examined recent advances in molecular identification of prokaryotic (i.e. bacteria) and eukaryotic (i.e. microalgae) associates, and palaeoecology, and place the partnership with bacteria and algae in the context of climate change. In critically reviewing the available fossil and modern data on symbiosis, we reveal a crucial role of microalgae in the response of LBF to ocean warming, and their capacity to colonise a variety of habitats, across both latitudes and broad depth ranges. Symbiont identity is a key factor enabling LBF to expand their geographic ranges when the sea-surface temperature increases. Our analyses showed that over the past 66 million years (My), diatom-bearing species were dominant in reef environments. The modern record shows that these species display a stable, persistent eukaryotic assemblage across their geographic distribution range, and are less dependent on symbiotic photosynthesis for survival. By contrast, dinoflagellate and chlorophytic species, which show a provincial distribution, tend to have a more flexible eukaryotic community throughout their range. This group is more dependent on their symbionts, and flexibility in their symbiosis is likely to be the driving force behind their evolutionary history, as they form a monophyletic group originating from a rhodophyte-bearing ancestor. The study of bacterial assemblages, while still in its infancy, is a promising field of study. Bacterial communities are likely to be shaped by the local environment, although a core bacterial microbiome is found in species with global distributions. Cryptic speciation is also an important factor that must be taken into consideration. As global warming intensifies, genetic divergence in hosts in addition to the range of flexibility/specificity within host-symbiont associations will be important elements in the continued evolutionary success of LBF species in a wide range of environments. Based on fossil and modern data, we conclude that the microbiome, which includes both algal and bacterial partners, is a key factor influencing the evolution of LBF. As a result, the microbiome assists LBF in colonising a wide range of habitats, and allowed them to become the most important calcifiers on shallow platforms worldwide during periods of ocean warming in the geologic past. Since LBF are crucial ecosystem engineers and prolific carbonate producers, the microbiome is a critical component that will play a central role in the responses of LBF to a changing ocean, and ultimately in shaping the future of coral reefs.

RevDate: 2018-11-21

Najafi A, Moradinasab M, Seyedabadi M, et al (2018)

First Molecular Identification of Symbiotic Archaea in a Sponge Collected from the Persian Gulf, Iran.

The open microbiology journal, 12:323-332 pii:TOMICROJ-12-323.

Background: Marine sponges are associated with numerically vast and phylogenetically diverse microbial communities at different geographical locations. However, little is known about the archaeal diversity of sponges in the Persian Gulf. The present study was aimed to identify the symbiotic archaea with a sponge species gathered from the Persian Gulf, Iran.

Methods: Sponge sample was collected from a depth of 3 m offshore Bushehr, Persian Gulf, Iran. Metagenomic DNA was extracted using a hexadecyl trimethyl ammonium bromide (CTAB) method. The COI mtDNA marker was used for molecular taxonomy identification of sponge sample. Also, symbiotic archaea were identified using the culture-independent analysis of the 16S rRNA gene and PCR- cloning.

Results: In this study, analysis of multilocus DNA marker and morphological characteristics revealed that the sponge species belonged to Chondrilla australiensis isolate PG_BU4. PCR cloning and sequencing showed that all of the sequences of archaeal 16S rRNA gene libraries clustered into the uncultured archaeal group.

Conclusion: The present study is the first report of the presence of the genus of Chondrilla in the Persian Gulf. Traditional taxonomy methods, when used along with molecular techniques, could play a significant role in the accurate taxonomy of sponges. Also, the uncultured archaea may promise a potential source for bioactive compounds. Further functional studies are needed to explore the role of the sponge-associated uncultured archaea as a part of the marine symbiosis.

RevDate: 2018-11-21

Gong S, Chai G, Xiao Y, et al (2018)

Flexible Symbiotic Associations of Symbiodinium With Five Typical Coral Species in Tropical and Subtropical Reef Regions of the Northern South China Sea.

Frontiers in microbiology, 9:2485.

The coral symbiont Symbiodinium plays important roles in the adaptation of coral to environmental changes. However, coral-Symbiodinium symbiotic associations are not well-understood in the South China Sea (SCS) whilst considering environmental factors and host taxa. In this study, next-generation sequencing of the internal transcribed spacer region 2 (ITS2) marker gene was used to explore the symbiotic associations between Symbiodinium and five typical coral species across tropical and subtropical reef regions of the SCS. The results showed that Acropora sp., Galaxea fascicularis, Platygyra lamellina, and Sarcophyton glaucum exhibited distinct Symbiodinium compositions between tropical and subtropical reef regions, whereas Porites lutea had stable Symbiodinium compositions. More heterogeneous Symbiodinium compositions among different coral species were observed in the tropical region, but there were no statistically significant differences in Symbiodinium compositions among different coral species in subtropical reef regions. There was a correlation between the Symbiodinium compositions and environmental factors, except for the composition of P. lutea. Symbiodinium subclades D1, D2, C71, C71a, C21, C3b, and C161 were primarily explained by the seawater temperature, nitrate, ammonia, and phosphate. Several host-specific Symbiodinium subclades (e.g., C15, C15.6, and C91) were observed in P. lutea as well. The findings of this study demonstrate the relationship of Symbiodinium diversity with coral hosts and the environment are helpful for elucidating the adaptation of corals to global climate change and anthropogenic disturbance.

RevDate: 2018-11-19

Aylward J, Wingfield BD, Dreyer LL, et al (2018)

Genomic overview of closely related fungi with different Protea host ranges.

Fungal biology, 122(12):1201-1214.

Genome comparisons of species with distinctive ecological traits can elucidate genetic divergence that influenced their differentiation. The interaction of a microorganism with its biotic environment is largely regulated by secreted compounds, and these can be predicted from genome sequences. In this study, we considered Knoxdaviesia capensis and Knoxdaviesia proteae, two closely related saprotrophic fungi found exclusively in Protea plants. We investigated their genome structure to compare their potential inter-specific interactions based on gene content. Their genomes displayed macrosynteny and were approximately 10 % repetitive. Both species had fewer secreted proteins than pathogens and other saprotrophs, reflecting their specialized habitat. The bulk of the predicted species-specific and secreted proteins coded for carbohydrate metabolism, with a slightly higher number of unique carbohydrate-degrading proteins in the broad host-range K. capensis. These fungi have few secondary metabolite gene clusters, suggesting minimal competition with other microbes and symbiosis with antibiotic-producing bacteria common in this niche. Secreted proteins associated with detoxification and iron sequestration likely enable these Knoxdaviesia species to tolerate antifungal compounds and compete for resources, facilitating their unusual dominance. This study confirms the genetic cohesion between Protea-associated Knoxdaviesia species and reveals aspects of their ecology that have likely evolved in response to their specialist niche.

RevDate: 2018-11-19

Poinar GO, FE Vega (2018)

A mid-Cretaceous ambrosia fungus, Paleoambrosia entomophila gen. nov. et sp. nov. (Ascomycota: Ophiostomatales) in Burmese (Myanmar) amber, and evidence for a femoral mycangium.

Fungal biology, 122(12):1159-1162.

An ambrosia fungus is described from filamentous sporodochia adjacent to a wood-boring ambrosia beetle (Coleoptera: Curculionidae: Platypodinae) in mid-Cretaceous Burmese amber. Yeast-like propagules and hyphal fragments of Paleoambrosia entomophila gen. nov. et sp. nov. occur in glandular sac mycangia located inside the femur of the beetle. This is the first record of a fossil ambrosia fungus, showing that symbiotic associations between wood-boring insects and ectosymbiotic fungi date back some 100 million years ago. The present finding moves the origin of fungus-growing by insects from the Oligocene to the mid-Cretaceous and suggests a Gondwanan origin.

RevDate: 2018-11-27

Ren CG, Kong CC, Wang SX, et al (2018)

Enhanced phytoremediation of uranium-contaminated soils by arbuscular mycorrhiza and rhizobium.

Chemosphere, 217:773-779 pii:S0045-6535(18)32192-1 [Epub ahead of print].

Uranium phytoextraction is a promising technology, however, facing difficult that limited plant biomass due to nutrient deficiency in the contaminated sites. The aim of this study is to evaluate the potential of a symbiotic associations of a legume Sesbania rostrata, rhizobia and arbuscular mycorrhiza fungi (AMF) for reclamation of uranium contaminated soils. Results showed AMF and rhizobia had a mutual beneficial relations in the triple symbiosis, which significantly increased plant biomass and uranium accumulation in S. rostrata plant. The highest uranium removal rates was observed in plant-AMF-rhizobia treated soils, in which 50.5-73.2% had been extracted, whereas 7.2-23.3% had been extracted in plant-treated soil. Also, the S. rostrata phytochelatin synthase (PCS) genes expression were increased in AMF and rhizobia plants compared with the plants. Meantime, content of malic acid, succinic acid and citric acid were elevated in S. rostrata root exudates of AMF and rhizobia inoculated plants. The facts suggest that the mutual interactions in the triple symbiosis help to improve phytoremediation efficiency of uranium by S. rostrata.

RevDate: 2018-11-21

Ma J, Zhu D, Chen QL, et al (2018)

Exposure to tetracycline perturbs the microbiome of soil oligochaete Enchytraeus crypticus.

The Science of the total environment, 654:643-650 pii:S0048-9697(18)34510-8 [Epub ahead of print].

Microbial symbiosis is essential for the normal development and growth of hosts. Past attention has mostly been paid to its effects on plants and vertebrates. The effects of environmental pressures such as antibiotics on the microbiome of soil fauna remain largely elusive. We used bacterial 16S rRNA gene high-throughput sequencing to examine the response of microbiome of soil invertebrate Enchytraeus crypticus to oral tetracycline exposure. After two-week exposure, tetracycline-free oat was used as food to monitor the restoration of E. crypticus microbiome. The results showed that Proteobacteria, Actinobacteria and Planctomycetes were the three dominant phyla in all samples, Rhizobiaceae and Kaistia were the most abundant family and genus in all samples, respectively. After 14 days tetracycline exposure, Planctomycetes declined dramatically from 33.05% to 3.28% (P = 0.016), but Actinobacteria elevated substantially from 2.47% to 23.65% (P = 0.004). The alpha-diversity of microbial community increased significantly after tetracycline exposure compared to the control (P = 0.014). Terminating tetracycline exposure led to the recovery of E. crypticus microbiome back to the background level within 14 days. Our results suggest that while tetracycline can disturb the microbiome in E. crypticus significantly, the effects of the antibiotic on E. crypticus microbiome may not be permanent but reversibly diminish after stopping exposure for a period of time. The results may contribute to extending our understanding of the effect of antibiotics on microbiome of soil invertebrates. CAPSULE: The microbiome of E. crypticus exposed to tetracycline is perturbed and reversibly restored after terminating the exposure.

RevDate: 2018-11-30

Limpens E, R Geurts (2018)

Transcriptional Regulation of Nutrient Exchange in Arbuscular Mycorrhizal Symbiosis.

Molecular plant pii:S1674-2052(18)30339-3 [Epub ahead of print].

RevDate: 2018-11-16

Schneider S, Schintlmeister A, Becana M, et al (2018)

Sulfate is transported at significant rates through the symbiosome membrane and is crucial for nitrogenase biosynthesis.

Plant, cell & environment [Epub ahead of print].

Legume-rhizobia symbioses play a major role in food production for an ever growing human population. In this symbiosis, dinitrogen is reduced ('fixed') to ammonia by the rhizobial nitrogenase enzyme complex and is secreted to the plant host cells, while dicarboxylic acids derived from photosynthetically-produced sucrose are transported into the symbiosomes and serve as respiratory substrates for the bacteroids. The symbiosome membrane contains high levels of SST1 protein, a sulfate transporter. Sulfate is an essential nutrient for all living organisms, but its importance for symbiotic nitrogen fixation and nodule metabolism has long been underestimated. Using chemical imaging, we demonstrate that the bacteroids take up 20-fold more sulfate than the nodule host cells. Furthermore, we show that nitrogenase biosynthesis relies on high levels of imported sulfate, making sulfur as essential as carbon for the regulation and functioning of symbiotic nitrogen fixation. Our findings thus establish the importance of sulfate and its active transport for the plant-microbe interaction that is most relevant for agriculture and soil fertility. This article provides a comprehensive explanation for the importance of the nodule specific sulfate transporter (SST1) and the role of sulfate by dissecting the sulfur distribution across the nodule tissue and directly linking sulfate incorporation to nitrogenase biosynthesis.

RevDate: 2018-11-16

Shrestha M, Compton KK, Mancl J, et al (2018)

Structure of the sensory domain of McpX from Sinorhizobium meliloti the first known bacterial chemotactic sensor for quaternary ammonium compounds.

The Biochemical journal pii:BCJ20180769 [Epub ahead of print].

The alpha-proteobacterium Sinorhizobium meliloti can live freely in the soil or engage in a symbiosis with its legume host. S. meliloti facilitates nitrogen-fixation in root nodules, thus providing pivotal, utilizable nitrogen to the host. The organism has eight chemoreceptors, namely McpT to McpZ and IcpA that facilitate chemotaxis. McpX is the first known bacterial sensor of quaternary amine compounds (QACs) such as choline and betaines. Because QACs are exuded at chemotaxis-relevant concentrations by germinating alfalfa seeds, McpX has been proposed to contribute to host-specific chemotaxis. We have determined the crystal structure of the McpX periplasmic region (McpXPR) in complex with the proline betaine at 2.7 Å resolution. In the crystal the protein forms a symmetric dimer with one proline betaine molecule bound to each monomer of McpXPR within membrane distal CACHE module. The ligand is bound through cation- interactions with four aromatic amino acid residues. Mutational analysis in conjunction with binding studies revealed that a conserved aspartate residue is pivotal for ligand binding. We discovered that, in a striking example of convergent evolution, the ligand binding site of McpXPR resembles that of a group of structurally unrelated betaine binding proteins including ProX and OpuAC. Through this comparison and docking studies we rationalized the specificity of McpXPR for this specific group of ligands. Collectively, our structural, biochemical, and molecular docking data have revealed the molecular determinants in McpX that are crucial for its rare ligand specificity for QACs.

RevDate: 2018-11-29

Dixit KK, Verma S, Singh OP, et al (2018)

Validation of SYBR green I based closed tube loop mediated isothermal amplification (LAMP) assay and simplified direct-blood-lysis (DBL)-LAMP assay for diagnosis of visceral leishmaniasis (VL).

PLoS neglected tropical diseases, 12(11):e0006922 pii:PNTD-D-18-01163.

BACKGROUND: The World Health Organization has targeted elimination of visceral leishmaniasis (VL) in the Indian subcontinent (ISC) by 2020. Despite distinctive decline seen in the number of VL cases in ISC, there is still a quest for development of a diagnostic test which has the utility for detection of active infection and relapse cases and as a test of cure. The present study validated the sensitivity and specificity of SYBR Green I based closed tube LAMP assay reported by us for diagnosis of VL.

METHODOLOGY: The validation study was carried out at two endemic sites in India, located at Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna and Institute of Medical Sciences (IMS), Banaras Hindu University (BHU), Varanasi. Standard operating protocols were provided at the two sites for applying LAMP assay on confirmed VL cases. The diagnostic accuracy of LAMP assay was evaluated by Receiver operator curve (ROC) analysis. Furthermore, a simplified LAMP assay based on direct blood lysis, DBL-LAMP, was developed and verified for its diagnostic accuracy.

PRINCIPAL FINDINGS: A total of 267 eligible participants were included in the study which comprised of 179 VL cases and 88 controls. Sensitivity and specificity of the LAMP assay were 98.32% (95% C.I- 95.2-99.7%) and 96.59% (95% C.I.-90.4-99.3%), respectively. ROC curve analysis depicted no significant difference between area under curve (AUCROC) for LAMP assay and rK39 RDT, indicative of LAMP as an excellent diagnostic test. DBL-LAMP assay, performed on 67 VL and 100 control samples, yielded a sensitivity of 93.05% (95% C.I- 84.75-97%) and specificity of 100% (95% C.I.- 96.30-100%).

CONCLUSIONS/SIGNIFICANCE: The validated closed tube LAMP for diagnosis of VL will provide impetus to the ongoing VL elimination programme in ISC. The assay based on direct blood lysis promotes its scope for application in field settings by further reducing time and cost.

RevDate: 2018-11-21

Yuyama I, Ishikawa M, Nozawa M, et al (2018)

Transcriptomic changes with increasing algal symbiont reveal the detailed process underlying establishment of coral-algal symbiosis.

Scientific reports, 8(1):16802 pii:10.1038/s41598-018-34575-5.

To clarify the establishment process of coral-algal symbiotic relationships, coral transcriptome changes during increasing algal symbiont densities were examined in juvenile corals following inoculation with the algae Symbiodinium goreaui (clade C) and S. trenchii (clade D), and comparison of their transcriptomes with aposymbiotic corals by RNA-sequencing. Since Symbiodinium clades C and D showed very different rates of density increase, comparisons were made of early onsets of both symbionts, revealing that the host behaved differently for each. RNA-sequencing showed that the number of differentially-expressed genes in corals colonized by clade D increased ca. two-fold from 10 to 20 days, whereas corals with clade C showed unremarkable changes consistent with a slow rate of density increase. The data revealed dynamic metabolic changes in symbiotic corals. In addition, the endocytosis pathway was also upregulated, while lysosomal digestive enzymes and the immune system tended to be downregulated as the density of clade D algae increased. The present dataset provides an enormous number of candidate symbiosis-related molecules that exhibit the detailed process by which coral-algal endosymbiosis is established.

RevDate: 2018-11-15

Georgieva MN, Little CTS, Bailey RJ, et al (2018)

Microbial-tubeworm associations in a 440 million year old hydrothermal vent community.

Proceedings. Biological sciences, 285(1891): pii:rspb.2018.2004.

Microorganisms are the chief primary producers within present-day deep-sea hydrothermal vent ecosystems, and play a fundamental role in shaping the ecology of these environments. However, very little is known about the microbes that occurred within, and structured, ancient vent communities. The evolutionary history, diversity and the nature of interactions between ancient vent microorganisms and hydrothermal vent animals are largely undetermined. The oldest known hydrothermal vent community that includes metazoans is preserved within the Ordovician to early Silurian Yaman Kasy massive sulfide deposit, Ural Mountains, Russia. This deposit contains two types of tube fossil attributed to annelid worms. A re-examination of these fossils using a range of microscopy, chemical analysis and nano-tomography techniques reveals the preservation of filamentous microorganisms intimately associated with the tubes. The microfossils bear a strong resemblance to modern hydrothermal vent microbial filaments, including those preserved within the mineralized tubes of the extant vent polychaete genus Alvinella The Yaman Kasy fossil filaments represent the oldest animal-microbial associations preserved within an ancient hydrothermal vent environment. They allude to a diverse microbial community, and also demonstrate that remarkable fine-scale microbial preservation can also be observed in ancient vent deposits, suggesting the possible existence of similar exceptionally preserved microfossils in even older vent environments.

RevDate: 2018-11-14

Stabb EV (2018)

Should they stay or should they go? Nitric oxide and the clash of regulators governing Vibrio fischeri biofilm formation.

Molecular microbiology [Epub ahead of print].

A key regulatory decision for many bacteria is the switch between biofilm formation and motile dispersal, and this dynamic is well illustrated in the light-organ symbiosis between the bioluminescent bacterium Vibrio fischeri and the Hawaiian bobtail squid. Biofilm formation mediated by the syp gene cluster helps V. fischeri transition from a dispersed planktonic lifestyle to a robust aggregate on the surface of the nascent symbiotic organ. However, the bacteria must then swim to pores and down into the deeper crypt tissues that they ultimately colonize. A number of positive and negative regulators control syp expression and biofilm formation, but until recently the environmental inputs controlling this clash between opposing regulatory mechanisms have been unclear. Thompson et al. have now shown that Syp-mediated biofilms can be repressed by a well known host-derived molecule: nitric oxide. This regulation is accomplished by the NO sensor HnoX exerting control over the biofilm regulator HahK. The discoveries reported here by Thompson et al. cast new light on a critical early stage of symbiotic initiation in the V. fischeri-squid model symbiosis, and more broadly it adds to a growing understanding of the role(s) that NO and HnoX play in biofilm regulation by many bacteria. This article is protected by copyright. All rights reserved.

RevDate: 2018-11-16

Farkas A, Pap B, Kondorosi É, et al (2018)

Antimicrobial Activity of NCR Plant Peptides Strongly Depends on the Test Assays.

Frontiers in microbiology, 9:2600.

The symbiosis specific NCR247 and NCR335 cationic plant peptides of Medicago truncatula have been shown to exert antimicrobial activity against a wide range of microbes. However, their antimicrobial efficiency is clearly limited by divalent cations. Here, the antibacterial and antifungal activities of NCR247 and NCR335 peptides were compared to those of the well-characterized peptide antibiotics polymyxin B and the aminoglycoside streptomycin on three model microbes, Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae as representatives of Gram-negative and Gram-positive bacteria as well as eukaryotic fungi. The aim of the study was to assess how the killing efficiency of these peptides depends on various, widely used antimicrobial susceptibility assays. Validated resazurin microdilution assay was used to determine minimal growth inhibitory concentrations in three general test media (MHB, MHBII and low-salt medium LSM). Bactericidal/fungicidal activities were determined by the commonly used drop plate assay. The natural plant peptides showed distinct characteristics, NCR247 had a generally high sensitivity for Ca2+ and Mg2+ in the medium, while NCR335 proved to be a robust and strong antimicrobial agent with comparable efficiency values to polymyxin B. Activity data were confirmed visually, both NCR247 and NCR335 treatments at minimal bactericidal concentrations induced complete disruption of the membranes and provoked cell lysis on all tested microorganisms as observed by scanning electron microscopy.

RevDate: 2018-11-26

Romano S, R Ansorge (2018)

Scientific communication strategies of microbiologists in the era of social media.

FEMS microbiology letters, 365(23):.

Over the last decades, the world of communication underwent drastic changes, and internet and social media emerged as essential vehicles for exchanging information. Following these trends, it is important that scientists adapt to changes and adopt optimal strategies to communicate with colleagues, lay people and institutions. We conducted an online survey to investigate the communication strategies of microbiologists and their colleagues from other disciplines. We collected data from 527 scholars from 57 countries, with ∼42% of them being microbiologists. We focused particularly on social media and found that >80% of participants used them for work, and that ∼50% of interviewed actively shared and gathered scientific contents from social media. Compared to colleagues from other fields, microbiologists were less averse to use social media for work and were also less accustomed to use pre-prints as a source and vehicle of information. However, a large proportion of microbiologists declared to have planned pre-print publications in the future. Surprisingly, our data revealed that age is a poor predictor of social media usage, but it is strongly associated with the type of social media used, the activity undertaken on them and the attitude towards pre-print publications. Considering the kaleidoscopic variety of scientific communication tools, our data might help to optimize the scientific promotion strategies among microbiologists.

RevDate: 2018-11-13

La A, Perré P, B Taidi (2018)

Process for symbiotic culture of Saccharomyces cerevisiae and Chlorella vulgaris for in situ CO2 mitigation.

Applied microbiology and biotechnology pii:10.1007/s00253-018-9506-3 [Epub ahead of print].

Industrial biotechnology relies heavily on fermentation processes that release considerable amounts of CO2. Apart from the fact that this CO2 represents a considerable part of the organic substrate, it has a negative impact on the environment. Microalgae cultures have been suggested as potential means of capturing the CO2 with further applications in high-value compounds production or directly for feed applications. We developed a sustainable process based on a mixed co-dominant culture of Saccharomyces cerevisiae and Chlorella vulgaris where the CO2 production and utilization controlled the microbial ecology of the culture. By mixing yeast and microalga in the same culture, the CO2 is produced in dissolved form and is available to the microalga avoiding degassing and dissolution phenomena. With this process, the CO2 production and utilization rates were balanced and a mutual symbiosis between the yeast and the microalga was set up in the culture. In this study, the reutilization of CO2 and growth of C. vulgaris was demonstrated. The two organism populations were balanced at approximately 20 × 106 cells ml-1 and almost all the CO2 produced by yeast was reutilized by microalga within 168 h of culture. The C. vulgaris inoculum preparation played a key role in establishing co-dominance of the two organisms. Other key factors in establishing symbiosis were the inoculum ratio of the two organisms and the growth medium design. A new method allowed the independent enumeration of each organism in a mixed culture. This study could provide a basis for the development of green processes of low environmental impact.

RevDate: 2018-11-12

Kalita M, W Małek (2018)

The ftsA gene as a molecular marker for phylogenetic studies in Bradyrhizobium and identification of Bradyrhizobium japonicum.

Journal of applied genetics pii:10.1007/s13353-018-0479-9 [Epub ahead of print].

The use of ftsA gene sequences for taxonomic studies of the genus Bradyrhizobium bacteria was assessed. The ftsA gene codes for an actin-like protein involved in prokaryotic cell division. Up to now, this gene has not been used as a phylogenetic marker for analysis of bacteria establishing root nodule symbiosis with Fabaceae plants. In this study, the ftsA gene sequences obtained for bradyrhizobia forming N2 fixing symbiosis with four Genisteae tribe plants growing in Poland and most of the type strains of the genus Bradyrhizobium species were analyzed and evaluated as molecular markers for phylogenetic studies of these bacteria for the first time. The ftsA gene sequences of all bradyrhizobial strains with completely or partially sequenced genomes, available in the GenBank database, were also included into the analysis. The phylogeny of the ftsA gene was compared to the phylogenies of other chromosomal genes commonly used in the studies of Bradyrhizobium bacteria. The results showed that the phylogenies of ftsA and the core genes recA and glnII were congruent, making the ftsA gene useful as a phylogenetic marker. Analysis of the ftsA gene sequences revealed a single-nucleotide polymorphism unique to Bradyrhizobium japonicum strains, and the potential use of this SNP for identification of this species was discussed.

RevDate: 2018-11-14

Treanor D, Pamminger T, WOH Hughes (2018)

The evolution of caste-biasing symbionts in the social hymenoptera.

Insectes sociaux, 65(4):513-519.

The separation of individuals into reproductive and worker castes is the defining feature of insect societies. However, caste determination is itself a complex phenomenon, dependent on interacting genetic and environmental factors. It has been suggested by some authors that widespread maternally transmitted symbionts such as Wolbachia may be selected to interfere with caste determination, whilst others have discounted this possibility on theoretical grounds. We argue that there are in fact three distinct evolutionary scenarios in which maternally transmitted symbionts might be selected to influence the process of caste determination in a social hymenopteran host. Each of these scenarios generate testable predictions which we outline here. Given the increasing recognition of the complexity and multi-faceted nature of caste determination in social insects, we argue that maternally transmitted symbionts should also be considered as possible factors influencing the development of social hymenopterans.

RevDate: 2018-11-20

Gaudioso-Pedraza R, Beck M, Frances L, et al (2018)

Callose-Regulated Symplastic Communication Coordinates Symbiotic Root Nodule Development.

Current biology : CB, 28(22):3562-3577.e6.

The formation of nitrogen-fixing nodules in legumes involves the initiation of synchronized programs in the root epidermis and cortex to allow rhizobial infection and nodule development. In this study, we provide evidence that symplastic communication, regulated by callose turnover at plasmodesmata (PD), is important for coordinating nodule development and infection in Medicago truncatula. Here, we show that rhizobia promote a reduction in callose levels in inner tissues where nodules initiate. This downregulation coincides with the localized expression of M. truncatula β-1,3-glucanase 2 (MtBG2), encoding a novel PD-associated callose-degrading enzyme. Spatiotemporal analyses revealed that MtBG2 expression expands from dividing nodule initials to rhizobia-colonized cortical and epidermal tissues. As shown by the transport of fluorescent molecules in vivo, symplastic-connected domains are created in rhizobia-colonized tissues and enhanced in roots constitutively expressing MtBG2. MtBG2-overexpressing roots additionally displayed reduced levels of PD-associated callose. Together, these findings suggest an active role for MtBG2 in callose degradation and in the formation of symplastic domains during sequential nodule developmental stages. Interfering with symplastic connectivity led to drastic nodulation phenotypes. Roots ectopically expressing β-1,3-glucanases (including MtBG2) exhibited increased nodule number, and those expressing MtBG2 RNAi constructs or a hyperactive callose synthase (under symbiotic promoters) showed defective nodulation phenotypes. Obstructing symplastic connectivity appears to block a signaling pathway required for the expression of NODULE INCEPTION (NIN) and its target NUCLEAR FACTOR-YA1 (NF-YA1) in the cortex. We conclude that symplastic intercellular communication is proactively enhanced by rhizobia, and this is necessary for appropriate coordination of bacterial infection and nodule development.

RevDate: 2018-11-20

Decelle J, Carradec Q, Pochon X, et al (2018)

Worldwide Occurrence and Activity of the Reef-Building Coral Symbiont Symbiodinium in the Open Ocean.

Current biology : CB, 28(22):3625-3633.e3.

The dinoflagellate microalga Symbiodinium sustains coral reefs, one of the most diverse ecosystems of the biosphere, through mutualistic endosymbioses with a wide diversity of benthic hosts [1]. Despite its ecological and economic importance, the presence of Symbiodinium in open oceanic waters remains unknown, which represents a significant knowledge gap to fully understand the eco-evolutionary trajectory and resilience of endangered Symbiodinium-based symbioses. Here, we document the existence of Symbiodinium (i.e., now the family Symbiodiniaceae [2]) in tropical- and temperate-surface oceans using DNA and RNA metabarcoding of size-fractionated plankton samples collected at 109 stations across the globe. Symbiodinium from clades A and C were, by far, the most prevalent and widely distributed lineages (representing 0.1% of phytoplankton reads), while other lineages (clades B, D, E, F, and G) were present but rare. Concurrent metatranscriptomics analyses using the Tara Oceans gene catalog [3] revealed that Symbiodinium clades A and C were transcriptionally active in the open ocean and expressed core metabolic pathways (e.g., photosynthesis, carbon fixation, glycolysis, and ammonium uptake). Metabarcodes and expressed genes of clades A and C were detected in small and large plankton size fractions, suggesting the existence of a free-living population and a symbiotic lifestyle within planktonic hosts, respectively. However, high-resolution genetic markers and microscopy are required to confirm the life history of oceanic Symbiodinium. Overall, the previously unknown, metabolically active presence of Symbiodinium in oceanic waters opens up new avenues for investigating the potential of this oceanic reservoir to repopulate coral reefs following stress-induced bleaching.

RevDate: 2018-11-12

Flores-Félix JD, Sánchez-Juanes F, García-Fraile P, et al (2018)

Phaseolus vulgaris is nodulated by the symbiovar viciae of several genospecies of Rhizobium laguerreae complex in a Spanish region where Lens culinaris is the traditionally cultivated legume.

Systematic and applied microbiology pii:S0723-2020(18)30367-9 [Epub ahead of print].

Phaseolus vulgaris and Lens culinaris are two legumes with different distribution centers that were introduced in Spain at different times, but in some regions L. culinaris has been traditionally cultivated and P. vulgaris did not. Here we analysed the rhizobia isolated from nodules of these two legumes in one of these regions. MALDI-TOF MS analysis showed that all isolated strains matched with Rhizobium laguerreae and the phylogenetic analysis of rrs, atpD and recA genes confirmed these results. The phylogenetic analysis of these core genes allowed the differentiation of several groups within R. laguerreae and unexpectedly, strains with housekeeping genes identical to that of the type strain of R. laguerreae presented some differences in the rrs gene. In some strains this gene contains an intervening sequence (IVS) identical to that found in Rhizobium strains nodulating several legumes in different geographical locations. The atpD, recA and nodC genes of all isolated strains clustered with those of strains nodulating L. culinaris in its distribution centers, but not with those nodulating P. vulgaris in theirs. Therefore, all these strains belong to the symbiovar viciae, including those isolated from P. vulgaris, which in the studied region established effective symbiosis with the common endosymbiont of L. culinaris, instead to with its common endosymbiont, the symbiovar phaseoli. These results are particularly interesting for biogeography studies, because they showed that, due its high promiscuity degree, P. vulgaris is able to establish symbiosis with local symbiovars well established in the soil after centuries of cultivation with other legumes.

RevDate: 2018-11-10

Fagorzi C, Checcucci A, diCenzo GC, et al (2018)

Harnessing Rhizobia to Improve Heavy-Metal Phytoremediation by Legumes.

Genes, 9(11): pii:genes9110542.

Rhizobia are bacteria that can form symbiotic associations with plants of the Fabaceae family, during which they reduce atmospheric di-nitrogen to ammonia. The symbiosis between rhizobia and leguminous plants is a fundamental contributor to nitrogen cycling in natural and agricultural ecosystems. Rhizobial microsymbionts are a major reason why legumes can colonize marginal lands and nitrogen-deficient soils. Several leguminous species have been found in metal-contaminated areas, and they often harbor metal-tolerant rhizobia. In recent years, there have been numerous efforts and discoveries related to the genetic determinants of metal resistance by rhizobia, and on the effectiveness of such rhizobia to increase the metal tolerance of host plants. Here, we review the main findings on the metal resistance of rhizobia: the physiological role, evolution, and genetic determinants, and the potential to use native and genetically-manipulated rhizobia as inoculants for legumes in phytoremediation practices.

RevDate: 2018-11-09

Rossi A, Bellone A, Fokin SI, et al (2018)

Detecting Associations Between Ciliated Protists and Prokaryotes with Culture-Independent Single-Cell Microbiomics: a Proof-of-Concept Study.

Microbial ecology pii:10.1007/s00248-018-1279-9 [Epub ahead of print].

Symbioses between prokaryotes and microbial eukaryotes, particularly ciliated protists, have been studied for a long time. Nevertheless, researchers have focused only on a few host genera and species, mainly due to difficulties in cultivating the hosts, and usually have considered a single symbiont at a time. Here, we present a pilot study using a single-cell microbiomic approach to circumvent these issues. Unicellular ciliate isolation followed by simultaneous amplification of eukaryotic and prokaryotic markers was used. Our preliminary test gave reliable and satisfactory results both on samples collected from different habitats (marine and freshwater) and on ciliates belonging to different taxonomic groups. Results suggest that, as already assessed for many macro-organisms like plants and metazoans, ciliated protists harbor distinct microbiomes. The applied approach detected new potential symbionts as well as new hosts for previously described ones, with relatively low time and cost effort and without culturing. When further developed, single-cell microbiomics for ciliates could be applied to a large number of studies aiming to unravel the evolutionary and ecological meaning of these symbiotic systems.

RevDate: 2018-11-14

Morris JJ (2018)

What is the hologenome concept of evolution?.

F1000Research, 7:.

All multicellular organisms are colonized by microbes, but a gestalt study of the composition of microbiome communities and their influence on the ecology and evolution of their macroscopic hosts has only recently become possible. One approach to thinking about the topic is to view the host-microbiome ecosystem as a "holobiont". Because natural selection acts on an organism's realized phenotype, and the phenotype of a holobiont is the result of the integrated activities of both the host and all of its microbiome inhabitants, it is reasonable to think that evolution can act at the level of the holobiont and cause changes in the "hologenome", or the collective genomic content of all the individual bionts within the holobiont. This relatively simple assertion has nevertheless been controversial within the microbiome community. Here, I provide a review of recent work on the hologenome concept of evolution. I attempt to provide a clear definition of the concept and its implications and to clarify common points of disagreement.

RevDate: 2018-11-14

Colella S, Parisot N, Simonet P, et al (2018)

Bacteriocyte Reprogramming to Cope With Nutritional Stress in a Phloem Sap Feeding Hemipteran, the Pea Aphid Acyrthosiphon pisum.

Frontiers in physiology, 9:1498.

Nutritional symbioses play a central role in the ability of insects to thrive on unbalanced diets and in ensuring their evolutionary success. A genomic model for nutritional symbiosis comprises the hemipteran Acyrthosiphon pisum, and the gamma-3-proteobacterium, Buchnera aphidicola, with genomes encoding highly integrated metabolic pathways. A. pisum feeds exclusively on plant phloem sap, a nutritionally unbalanced diet highly variable in composition, thus raising the question of how this symbiotic system responds to nutritional stress. We addressed this by combining transcriptomic, phenotypic and life history trait analyses to determine the organismal impact of deprivation of tyrosine and phenylalanine. These two aromatic amino acids are essential for aphid development, are synthesized in a metabolic pathway for which the aphid host and the endosymbiont are interdependent, and their concentration can be highly variable in plant phloem sap. We found that this nutritional challenge does not have major phenotypic effects on the pea aphid, except for a limited weight reduction and a 2-day delay in onset of nymph laying. Transcriptomic analyses through aphid development showed a prominent response in bacteriocytes (the core symbiotic tissue which houses the symbionts), but not in gut, thus highlighting the role of bacteriocytes as major modulators of this homeostasis. This response does not involve a direct regulation of tyrosine and phenylalanine biosynthetic pathway and transporter genes. Instead, we observed an extensive transcriptional reprogramming of the bacteriocyte with a rapid down-regulation of genes encoding sugar transporters and genes required for sugar metabolism. Consistently, we observed continued overexpression of the A. pisum homolog of RRAD, a small GTPase implicated in repressing aerobic glycolysis. In addition, we found increased transcription of genes involved in proliferation, cell size control and signaling. We experimentally confirmed the significance of these gene expression changes detecting an increase in bacteriocyte number and cell size in vivo under tyrosine and phenylalanine depletion. Our results support a central role of bacteriocytes in the aphid response to amino acid deprivation: their transcriptional and cellular responses fine-tune host physiology providing the host insect with an effective way to cope with the challenges posed by the variability in composition of phloem sap.

RevDate: 2018-11-14

Roth R, Chiapello M, Montero H, et al (2018)

A rice Serine/Threonine receptor-like kinase regulates arbuscular mycorrhizal symbiosis at the peri-arbuscular membrane.

Nature communications, 9(1):4677 pii:10.1038/s41467-018-06865-z.

In terrestrial ecosystems most plant species live in mutualistic symbioses with nutrient-delivering arbuscular mycorrhizal (AM) fungi. Establishment of AM symbioses includes transient, intracellular formation of fungal feeding structures, the arbuscules. A plant-derived peri-arbuscular membrane (PAM) surrounds the arbuscules, mediating reciprocal nutrient exchange. Signaling at the PAM must be well coordinated to achieve this dynamic cellular intimacy. Here, we identify the PAM-specific Arbuscular Receptor-like Kinase 1 (ARK1) from maize and rice to condition sustained AM symbiosis. Mutation of rice ARK1 causes a significant reduction in vesicles, the fungal storage structures, and a concomitant reduction in overall root colonization by the AM fungus Rhizophagus irregularis. Arbuscules, although less frequent in the ark1 mutant, are morphologically normal. Co-cultivation with wild-type plants restores vesicle and spore formation, suggesting ARK1 function is required for the completion of the fungal life-cycle, thereby defining a functional stage, post arbuscule development.

RevDate: 2018-11-09

Parakh SK, Praveen P, Loh KC, et al (2019)

Wastewater treatment and microbial community dynamics in a sequencing batch reactor operating under photosynthetic aeration.

Chemosphere, 215:893-903.

A sequencing batch bioreactor (SBR) treating municipal wastewater was photosynthetically aerated using microalgae cultivated in a photobioreactor (PBR). Symbiotic interactions and CO2/O2 exchange were established between activated sludge in the SBR and microalgae in the PBR through hydrophobic hollow fiber membranes. Photosynthetic aeration enhanced COD removal in the SBR from 52.2% (without external aeration) to 90.3%, whereas N-NH4+ and P-PO43- removal increased by 63.5% and 90.4%, respectively. The SBR performance under photosynthetic aeration was comparable to that under mechanical aeration. However, no nitrification was observed in the SBR, indicating oxygen limitation and poor growth condition for nitrifiers. In the PBR, there was a rapid increase in biomass concentration and it stabilized at 3.0 g/L after 22 days of operation. High nitrogen demand in the PBR indicated the steady flow of inorganic carbon from the SBR through the membranes. Prolonged oxygen limitation and massive sludge attachment on the membranes resulted in low suspended sludge concentration in the SBR. Microbial community analysis indicated gradual enrichment of facultative and strictly anaerobic microorganisms in the SBR. These results highlight the potential of microalgae in lowering the cost of wastewater aeration and underline the challenges in sustaining symbiotic gas exchange during long-term.

RevDate: 2018-11-14

Buendia L, Girardin A, Wang T, et al (2018)

LysM Receptor-Like Kinase and LysM Receptor-Like Protein Families: An Update on Phylogeny and Functional Characterization.

Frontiers in plant science, 9:1531.

Members of plant specific families of receptor-like kinases (RLKs) and receptor-like proteins (RLPs), containing 3 extracellular LysMs have been shown to directly bind and/or to be involved in perception of lipo-chitooligosaccharides (LCO), chitooligosaccharides (CO), and peptidoglycan (PGN), three types of GlcNAc-containing molecules produced by microorganisms. These receptors are involved in microorganism perception by plants and can activate different plant responses leading either to symbiosis establishment or to defense responses against pathogens. LysM-RLK/Ps belong to multigenic families. Here, we provide a phylogeny of these families in eight plant species, including dicotyledons and monocotyledons, and we discuss known or putative biological roles of the members in each of the identified phylogenetic groups. We also report and discuss known biochemical properties of the LysM-RLK/Ps.

RevDate: 2018-11-20

Hujber Z, Horváth G, Petővári G, et al (2018)

GABA, glutamine, glutamate oxidation and succinic semialdehyde dehydrogenase expression in human gliomas.

Journal of experimental & clinical cancer research : CR, 37(1):271 pii:10.1186/s13046-018-0946-5.

BACKGROUND: Bioenergetic characterisation of malignant tissues revealed that different tumour cells can catabolise multiple substrates as salvage pathways, in response to metabolic stress. Altered metabolism in gliomas has received a lot of attention, especially in relation to IDH mutations, and the associated oncometabolite D-2-hydroxyglutarate (2-HG) that impact on metabolism, epigenetics and redox status. Astrocytomas and oligodendrogliomas, collectively called diffuse gliomas, are derived from astrocytes and oligodendrocytes that are in metabolic symbiosis with neurons; astrocytes can catabolise neuron-derived glutamate and gamma-aminobutyric acid (GABA) for supporting and regulating neuronal functions.

METHODS: Metabolic characteristics of human glioma cell models - including mitochondrial function, glycolytic pathway and energy substrate oxidation - in relation to IDH mutation status and after 2-HG incubation were studied to understand the Janus-faced role of IDH1 mutations in the progression of gliomas/astrocytomas. The metabolic and bioenergetic features were identified in glioma cells using wild-type and genetically engineered IDH1-mutant glioblastoma cell lines by metabolic analyses with Seahorse, protein expression studies and liquid chromatography-mass spectrometry.

RESULTS: U251 glioma cells were characterised by high levels of glutamine, glutamate and GABA oxidation. Succinic semialdehyde dehydrogenase (SSADH) expression was correlated to GABA oxidation. GABA addition to glioma cells increased proliferation rates. Expression of mutated IDH1 and treatment with 2-HG reduced glutamine and GABA oxidation, diminished the pro-proliferative effect of GABA in SSADH expressing cells. SSADH protein overexpression was found in almost all studied human cases with no significant association between SSADH expression and clinicopathological parameters (e.g. IDH mutation).

CONCLUSIONS: Our findings demonstrate that SSADH expression may participate in the oxidation and/or consumption of GABA in gliomas, furthermore, GABA oxidation capacity may contribute to proliferation and worse prognosis of gliomas. Moreover, IDH mutation and 2-HG production inhibit GABA oxidation in glioma cells. Based on these data, GABA oxidation and SSADH activity could be additional therapeutic targets in gliomas/glioblastomas.

RevDate: 2018-11-08

Wang T, Song Z, Wang X, et al (2018)

Functional Insights into the Roles of Hormones in the Dendrobium officinale-Tulasnella sp. Germinated Seed Symbiotic Association.

International journal of molecular sciences, 19(11): pii:ijms19113484.

Dendrobium is one of the largest genera in the Orchidaceae, and D. officinale is used in traditional medicine, particularly in China. D. officinale seeds are minute and contain limited energy reserves, and colonization by a compatible fungus is essential for germination under natural conditions. When the orchid mycorrhizal fungi (OMF) initiates symbiotic interactions with germination-driven orchid seeds, phytohormones from the orchid or the fungus play key roles, but the details of the possible biochemical pathways are still poorly understood. In the present study, we established a symbiotic system between D. officinale and Tulasnella sp. for seed germination. RNA-Seq was used to construct libraries of symbiotic-germinated seeds (DoTc), asymbiotic-germinated seeds (Do), and free-living OMF (Tc) to investigate the expression profiles of biosynthesis and metabolism pathway genes for three classes of endogenous hormones: JA (jasmonic acid), ABA (abscisic acid) and SLs (strigolactones), in D. officinale seeds and OMF under symbiotic and asymbiotic conditions. Low concentrations of endogenous JA, ABA, or SLs were detected in the D. officinale-Tulasnella symbiont compared with the asymbiotic tissues. Gene annotation results suggest that the expression of DEGs (differentially expressed genes) related to JA and ABA biosynthesis from D. officinale were down-regulated, while most of the key DEGs related to SL biosynthesis from D. officinale were up-regulated in the symbiotic germinated seeds compared with the asymbiotic germinated seeds. Moreover, in the OMF, we found a significantly up-regulated differential expression of the JA and ABA biosynthesis-related genes in the symbiotic interaction, with the opposite expression trends to those found in Dendrobium. This indicates that Dendrobium seed symbiotic germination may be stimulated by the apparent involvement of the OMF in the production of hormones, and relatively low concentrations of endogenous JA, ABA, or SLs might be maintained to promote the growth of the D. officinale-Tulasnella symbiotic protocorm-like body. These results will increase our understanding of the possible roles played by endogenous hormones in the regulation of the orchid-fungus symbiosis.

RevDate: 2018-11-07

Somporn P, Walters L, J Ash (2018)

Expectations of rural community-based medical education: a case study from Thailand.

Rural and remote health, 18(4):4709.

INTRODUCTION: Thailand has recognised and sought to remedy rural medical workforce shortages. The Collaborative Project to Increase Production of Rural Doctors (CPIRD) has improved rural workforce recruitment through publicly funding medical school places for students with rural backgrounds. However, challenges in rural retention continue. CPIRD is seeking to develop a Thai rural community-based medical education (RCBME) program in the southern region of Thailand to improve preparation for rural practice and rural medical retention rates. Prospective stakeholder consultations will allow the understanding of expectations and concerns of stakeholders required for successful RCBME implementation. This study aims to explore stakeholders' expectations of the Southern Thai RCBME initiative.

METHODS: A qualitative case study comprised a purposive sample of students, clinical educators, policymakers, rural health professionals and local community stakeholders, all likely to be involved in a new RCBME program in Songkhla Province, Thailand. Individual semi-structured interviews were audiotaped, transcribed in Thai and coded using Worley's symbiosis framework. Following this, text and quotes used in the initial analysis were translated into English, discussed and reanalysed for emergent themes across the framework.

RESULTS: A total of 21 participants contributed RCBME stakeholder perspectives. They demonstrated expectations and concerns in each of the relationship axes of the symbiosis model including the clinical, institutional, social and personal axes. Three major themes emerged from the data that integrated stakeholder perspectives on the implication of RCBME in Thailand. These themes were a dramatic shift in Thai medical education paradigm, seeing rural practice as a future career, and collaboration to improve education and health in rural services.

CONCLUSION: This study comprehensively describes Thai stakeholder expectations of RCBME and demonstrates that, although some principles of RCBME are universal, context does influence the expectations and capacity of stakeholders to contribute to RCBME. Prospective formal stakeholder engagement is recommended to ensure successful implementation of new educational innovations.

RevDate: 2018-11-07

Sepp SK, Davison J, Jairus T, et al (2018)

Non-random association patterns in a plant-mycorrhizal fungal network reveal host-symbiont specificity.

Molecular ecology [Epub ahead of print].

Arbuscular mycorrhizal (AM) fungi are obligate plant symbionts that have important functions in most terrestrial ecosystems, but there remains an incomplete understanding of host-fungus specificity and the relationships between species or functional groups of plants and AM fungi. Here, we aimed to provide a comprehensive description of plant-AM fungal interactions in a biodiverse semi-natural grassland. We sampled all plant species in a 1000 m2 homogeneous plot of dry calcareous grassland in two seasons (summer and autumn) and identified root-colonizing AM fungi by SSU rDNA sequencing. In the network of 33 plant and 100 AM fungal species, we found a significant effect of both host plant species and host plant functional group on AM fungal richness and community composition. Comparison with network null models revealed a larger-than-random degree of partner selectivity among plants. Grasses harbored a larger number of AM fungal partners and were more generalist in partner selection, compared with forbs. More generalist partner association and lower specialization were apparent among obligately, compared with facultatively, mycorrhizal plant species and among locally more abundant plant species. This study provides the most complete dataset of co-occurring plant and AM fungal taxa to date, showing that at this particular site, the interaction network is assembled non-randomly, with moderate selectivity in associations between plant species and functional groups and their fungal symbionts. This article is protected by copyright. All rights reserved.

RevDate: 2018-11-07

Joshi S, Cook E, MS Mannoor (2018)

Bacterial Nanobionics via 3D Printing.

Nano letters [Epub ahead of print].

Investigating the multidimensional integration between different microbiological kingdoms possesses potential toward engineering next-generation bionic architectures. Bacterial and fungal kingdom exhibits mutual symbiosis that can offer advanced functionalities to these bionic architectures. Moreover, functional nanomaterials can serve as probing agents for accessing newer information from microbial organisms due to their dimensional similarities. In this article, a bionic mushroom was created by intertwining cyanobacterial cells with graphene nanoribbons (GNRs) onto the umbrella-shaped pileus of mushroom for photosynthetic bioelectricity generation. These seamlessly merged GNRs function as agents for mediating extracellular electron transport from cyanobacteria resulting in photocurrent generation. Additionally, three-dimensional (3D) printing technique was used to assemble cyanobacterial cells in anisotropic, densely packed geometry resulting in adequate cell-population density for efficient collective behavior. These 3D printed cyanobacterial colonies resulted in comparatively higher photocurrent (almost 8-fold increase) than isotropically casted cyanobacteria of similar seeding density. An insight of the proposed integration between cyanobacteria and mushroom derives remarkable advantage that arises from symbiotic relationship, termed here as engineered bionic symbiosis. Existence of this engineered bionic symbiosis was confirmed by UV-visible spectroscopy and standard plate counting method. Taken together, the present study augments scientific understanding of multidimensional integration between the living biological microworld and functional abiotic nanomaterials to establish newer dimensionalities toward advancement of bacterial nanobionics.

RevDate: 2018-11-14

Chashchina OE, Chibilev AA, Veselkin DV, et al (2018)

The Natural Abundance of Heavy Nitrogen Isotope (15N) in Plants Increases near a Large Copper Smelter.

Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 482(1):198-201.

The ratio of stable isotopes of nitrogen (15N and 14N) has been assessed in leaves of the forest plants from different functional groups (with ectomycorrhiza, ericoid, and arbuscular mycorrhiza; in a nitrogen-fixing symbiosis) under the conditions of strong transformation of ecosystems by the Karabashsky Copper-Smelting Plant effluents in the Southern Urals. The abundance of 15N in the plants generally increases in polluted habitats. The abundance of the heavy isotope 15N increases significantly with pollution in ericaceous dwarf shrubs (by 3.3‰) and herbs with arbuscular mycorrhizae (by 2.8‰). This indicates a strong alteration in conditions or modes of plant mineral nutrition under the influence of heavy metal pollution of forest ecosystems.

RevDate: 2018-11-07

Alvarado-López CJ, Dasgupta-Schubert N, Ambriz JE, et al (2018)

Lead uptake by the symbiotic Daucus carota L.-Glomus intraradices system and its effect on the morphology of extra- and intraradical fungal microstructures.

Environmental science and pollution research international pii:10.1007/s11356-018-3569-7 [Epub ahead of print].

This work examines the strategies adopted by an arbuscular mycorrhizal symbiotic system to ameliorate environmental Pb stress by examining the concentrations of P, Fe, and Pb in the fungal microstructures and the host's root. In vitro cultures of Ri-T DNA-transformed carrot (Daucus carota L.) roots were inoculated with Glomus intraradices and treated with Pb(NO3)2 solution and the extraradical spores and mycelia (S/M) and the root with the vesicles, mycelia, and root cells were subsequently analyzed by polarized energy dispersive x-ray fluorescence (PEDXRF) spectrometry. Upon Pb treatment, within the root, the percentages of mycorrhizal colonization, the vesicles, and mycelia increased as well as the areas of the vesicles and the (extraradical) spores, although the number of spores and arbuscules decreased. The S/M and the mycorrhizal root showed enhanced concentrations of Pb, Fe, and P. These were particularly marked for Fe in the Pb-treated cultures. This indicates a synergistic relationship between the arbuscular mycorrhizal fungus and the host that confers a higher Pb tolerance to the latter by the induction of higher Fe absorption in the host. The intraradical vesicle, mycelia, and arbuscule numbers are interpreted as a "tactic to divert" the intraradical Pb traffic away from the root cells to the higher affinity cell walls of the arbuscular mycorrhizal fungi (AMF) microstructures in the apoplast. The results of this work show that the symbiosis between the AMF G. intraradices and the host plant D. carota distinctly improves the latter's Pb tolerance, and imply that the appropriate metal tolerant host-AMF combinations could be employed in process designs for the phytoremediation of Pb.

RevDate: 2018-11-14

Jones VAS, Bucher M, Hambleton EA, et al (2018)

Microinjection to deliver protein, mRNA, and DNA into zygotes of the cnidarian endosymbiosis model Aiptasia sp.

Scientific reports, 8(1):16437 pii:10.1038/s41598-018-34773-1.

Reef-building corals depend on an intracellular symbiosis with photosynthetic dinoflagellates for their survival in nutrient-poor oceans. Symbionts are phagocytosed by coral larvae from the environment and transfer essential nutrients to their hosts. Aiptasia, a small tropical marine sea anemone, is emerging as a tractable model system for coral symbiosis; however, to date functional tools and genetic transformation are lacking. Here we have established an efficient workflow to collect Aiptasia eggs for in vitro fertilization and microinjection as the basis for experimental manipulations in the developing embryo and larvae. We demonstrate that protein, mRNA, and DNA can successfully be injected into live Aiptasia zygotes to label actin with recombinant Lifeact-eGFP protein; to label nuclei and cell membranes with NLS-eGFP and farnesylated mCherry translated from injected mRNA; and to transiently drive transgene expression from an Aiptasia-specific promoter, respectively, in embryos and larvae. These proof-of-concept approaches pave the way for future functional studies of development and symbiosis establishment in Aiptasia, a powerful model to unravel the molecular mechanisms underlying intracellular coral-algal symbiosis.

RevDate: 2018-11-07

Wang J, Wang J, Liu C, et al (2018)

Identification of Soybean Genes Whose Expression is Affected by the Ensifer fredii HH103 Effector Protein NopP.

International journal of molecular sciences, 19(11): pii:ijms19113438.

In some legume⁻rhizobium symbioses, host specificity is influenced by rhizobial nodulation outer proteins (Nops). However, the genes encoding host proteins that interact with Nops remain unknown. We generated an Ensifer fredii HH103 NopP mutant (HH103ΩNopP), and analyzed the nodule number (NN) and nodule dry weight (NDW) of 10 soybean germplasms inoculated with the wild-type E. fredii HH103 or the mutant strain. An analysis of recombinant inbred lines (RILs) revealed the quantitative trait loci (QTLs) associated with NopP interactions. A soybean genomic region containing two overlapping QTLs was analyzed in greater detail. A transcriptome analysis and qRT-PCR assay were used to identify candidate genes encoding proteins that interact with NopP. In some germplasms, NopP positively and negatively affected the NN and NDW, while NopP had different effects on NN and NDW in other germplasms. The QTL region in chromosome 12 was further analyzed. The expression patterns of candidate genes Glyma.12g031200 and Glyma.12g073000 were determined by qRT-PCR, and were confirmed to be influenced by NopP.

RevDate: 2018-11-06

Wiedenmann J, C D'Angelo (2018)

Symbiosis: High-Carb Diet of Reef Corals as Seen from Space.

Current biology : CB, 28(21):R1263-R1265.

High levels of phytoplankton visible in satellite imagery are correlated with an increased uptake of carbon compounds by corals. This suggests that corals rely less on carbon production by photosynthetic symbionts when other resources are plentiful, and that the changes in the acquisition mode of carbon can be inferred by remote-sensing techniques.

RevDate: 2018-11-05

Xu Y, Liu F, Li X, et al (2018)

The mycorrhiza-induced maize ZmPt9 gene affects root development and phosphate availability in nonmycorrhizal plant.

Plant signaling & behavior [Epub ahead of print].

The arbuscular mycorrhizal (AM)-induced ZmPt9 gene is an orthologous to some AM-inducible phosphate (Pi) transporter genes involved in Pi-starvation responses. Promoter GFP assay confirmed its transcript was localized surrounding arbuscule in arbuscule-containing cells. But this gene was not an AM fungi-specific gene. Its function in nonmycorrhizal seedlings was verified through phenotypic analysis of ZmPt9-overexpression Arabidopsis. Overexpression of ZmPt9 in Arabidopsis exhibited increased primary root length and lateral root formation. Furthermore, ZmPt9-overexpression Arabidopsis plants contained more phosphorus (P) than that of wild type. The affection of ZmPt9 in nonmycorrhizal Arabidopsis leads to the hypothesis that symbiosis-inducible genes are also involved in root development and Pi accumulation in AM-independent manner.

RevDate: 2018-11-29

Hendrikx T, B Schnabl (2018)

Antimicrobial proteins: intestinal guards to protect against liver disease.

Journal of gastroenterology pii:10.1007/s00535-018-1521-8 [Epub ahead of print].

Alterations of gut microbes play a role in the pathogenesis and progression of many disorders including liver and gastrointestinal diseases. Both qualitative and quantitative changes in gut microbiota have been associated with liver disease. Intestinal dysbiosis can disrupt the integrity of the intestinal barrier leading to pathological bacterial translocation and the initiation of an inflammatory response in the liver. In order to sustain symbiosis and protect from pathological bacterial translocation, antimicrobial proteins (AMPs) such as a-defensins and C-type lectins are expressed in the gastrointestinal tract. In this review, we provide an overview of the role of AMPs in different chronic liver disease such as alcoholic steatohepatitis, non-alcoholic fatty liver disease, and cirrhosis. In addition, potential approaches to modulate the function of AMPs and prevent bacterial translocation are discussed.

RevDate: 2018-11-30

Meng F, Xi L, Liu D, et al (2018)

Effects of light intensity on oxygen distribution, lipid production and biological community of algal-bacterial granules in photo-sequencing batch reactors.

Bioresource technology, 272:473-481 pii:S0960-8524(18)31491-3 [Epub ahead of print].

The effects of light intensity (0-225 µmol m-2 s-1) on oxygen distribution, lipid production and biological community structure of algal-bacterial granules were investigated in six identical photo-sequencing batch reactors (with a dark/light cycle of 12 h/12 h). Typically green algal-bacterial granules could be developed at a light intensity of ≥135 µmol m-2 s-1. The lipid content was significantly increased under higher light intensity, while the percentage of saturated fatty acid methyl esters was remarkably decreased. Results showed that light intensity ≥90 µmol m-2 s-1 yielded enough O2 production from algae, creating aerobic/anoxic zone (0.3-0.6 mg-O2/L) in the core of granules and thus efficient algal-bacterial symbiosis system. Enhanced nitrogen and phosphorus removals were achieved in the reactors with stronger light illumination, probably attributable to the enrichment of ammonia oxidizing bacteria (Comamonadaceae and Nitrosomonadaceae) and algae (Navicula and Stigeoclonium). Illuminance ≥180 µmol m-2 s-1 was found to be unfavorable for Nitrospiraceae.

RevDate: 2018-11-14

Kim TH, Kim D, Gautam A, et al (2018)

CpG-DNA exerts antibacterial effects by protecting immune cells and producing bacteria-reactive antibodies.

Scientific reports, 8(1):16236 pii:10.1038/s41598-018-34722-y.

CpG-DNA activates various immune cells, contributing to the host defense against bacteria. Here, we examined the biological function of CpG-DNA in the production of bacteria-reactive antibodies. The administration of CpG-DNA increased survival in mice following infection with methicillin-resistant S. aureus and protected immune cell populations in the peritoneal cavity, bone marrow, and spleen. CpG-DNA injection likewise increased bacteria-reactive antibodies in the mouse peritoneal fluid and serum, which was dependent on TLR9. B cells isolated from the peritoneal cavity produced bacteria-reactive antibodies in vitro following CpG-DNA administration that enhanced the phagocytic activity of the peritoneal cells. The bacteria-reactive monoclonal antibody enhanced phagocytosis in vitro and protected mice after S. aureus infection. Therefore, we suggest that CpG-DNA enhances the antibacterial activity of the immune system by protecting immune cells and triggering the production of bacteria-reactive antibodies. Consequently, we believe that monoclonal antibodies could aid in the treatment of antibiotic-resistant bacterial infections.


ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

Electronic Scholarly Publishing
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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).


ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.


Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )