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Bibliography on: Mitochondrial Evolution

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ESP: PubMed Auto Bibliography 14 Nov 2022 at 02:05 Created: 

Mitochondrial Evolution

The endosymbiotic hypothesis for the origin of mitochondria (and chloroplasts) suggests that mitochondria are descended from specialized bacteria (probably purple nonsulfur bacteria) that somehow survived endocytosis by another species of prokaryote or some other cell type, and became incorporated into the cytoplasm.

Created with PubMed® Query: mitochondria AND evolution NOT 26799652[PMID] NOT 33634751[PMID] NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2022-11-08

Weaver RJ, Rabinowitz S, Thueson K, et al (2022)

Genomic Signatures of Mitonuclear Coevolution in Mammals.

Molecular biology and evolution, 39(11):.

Mitochondrial (mt) and nuclear-encoded proteins are integrated in aerobic respiration, requiring co-functionality among gene products from fundamentally different genomes. Different evolutionary rates, inheritance mechanisms, and selection pressures set the stage for incompatibilities between interacting products of the two genomes. The mitonuclear coevolution hypothesis posits that incompatibilities may be avoided if evolution in one genome selects for complementary changes in interacting genes encoded by the other genome. Nuclear compensation, in which deleterious mtDNA changes are offset by compensatory nuclear changes, is often invoked as the primary mechanism for mitonuclear coevolution. Yet, direct evidence supporting nuclear compensation is rare. Here, we used data from 58 mammalian species representing eight orders to show strong correlations between evolutionary rates of mt and nuclear-encoded mt-targeted (N-mt) proteins, but not between mt and non-mt-targeted nuclear proteins, providing strong support for mitonuclear coevolution across mammals. N-mt genes with direct mt interactions also showed the strongest correlations. Although most N-mt genes had elevated dN/dS ratios compared to mt genes (as predicted under nuclear compensation), N-mt sites in close contact with mt proteins were not overrepresented for signs of positive selection compared to noncontact N-mt sites (contrary to predictions of nuclear compensation). Furthermore, temporal patterns of N-mt and mt amino acid substitutions did not support predictions of nuclear compensation, even in positively selected, functionally important residues with direct mitonuclear contacts. Overall, our results strongly support mitonuclear coevolution across ∼170 million years of mammalian evolution but fail to support nuclear compensation as the major mode of mitonuclear coevolution.

RevDate: 2022-11-07
CmpDate: 2022-11-07

De AK, Bhattacharya D, Sawhney S, et al (2022)

Molecular characterization of Rhipicephalus microplus in Andaman and Nicobar Islands, India: an insight into genetic assemblages.

Journal of genetics, 101:.

The tick, Rhipicephalus microplus is considered as the most notorious ectoparasite of veterinary importance in tropical and sub-tropical regions of the world. The present study deals with the molecular characterization of R. microplus in different regions of Andaman and Nicobar Islands using sequence information of mitochondrial cytochrome C oxidase subunit I (COX1) and their phylogenetic relationship with other Indian R. microplus genotypes. DNA polymorphism study identified a total of eight haplotypes with haplotype diversity of 0.909 ± 0.065 and nucleotide diversity of 0.01911 ± 0.00493. Currently, R. microplus complex consists of five taxa; R. microplus clade A sensu Burger et al. (2014), R. microplus clade B sensu Burger et al. (2014), R. microplus clade C sensu Low et al. (2015), R. australis and R. annulatus. Phylogenetic analysis revealed the presence of two clades (clade A and clade C) of R. microplus in Andaman and Nicobar isolates; Nicobar isolates belonged to clade A whereas Andaman isolates belonged to clade C of R. microplus complex. All the other Indian sequences retrieved from GenBank belonged to clade C of R. microplus complex. Andaman isolates under clade C of R. microplus were phylogenetically distinct from Indian isolates, which indicates independent speciation under isolated island milieu. In Indian isolates, no host-specific or geographical location-specific sub-clustering was observed which indicates the species jumping potential of the R. microplus tick. Therefore, this study indicated the presence of two different genetic makeup of R. microplus complex in two areas of the Andaman and Nicobar archipelago separated by a natural geographical barrier. This indicates presence of two different founding populations of ticks, one in the south and north-middle Andaman and the other in Nicobar Island.

RevDate: 2022-11-07
CmpDate: 2022-11-07

Joshi BD, Kumar V, De R, et al (2022)

Mitochondrial cytochrome b indicates the presence of two paraphyletic diverged lineages of the blue sheep Pseudois nayaur across the Indian Himalaya: conservation implications.

Molecular biology reports, 49(11):11177-11186.

BACKGROUND: Populations exhibit signatures of local adaptive traits due to spatial and environmental heterogeneity resulting in microevolution. The blue sheep is widely distributed across the high Asian mountains and are the snow leopard's principal prey species. These mountains differ in their evolutionary history due to differential glaciation and deglaciation periods, orography, and rainfall patterns, and such factors causes diversification in species.

METHODS AND RESULTS: Therefore, we assess the phylogeographic status of blue sheep using the mitochondrial cytochrome b gene (220 bp) across the Indian Himalayan region (IHR) and its relationship with other populations. Of the observed five haplotypes, two and three were from the western Himalayas (WH) and eastern Himalayas (EH) respectively. One of the haplotypes from WH was shared with the population of Pamir plateau, suggesting historical maternal connectivity between these areas. The phylogenetic analyses split the blue sheep into two paraphyletic clades, and western and eastern populations of IHR were within the Pamir and Tibetan plateau clades, respectively. We observed a relatively higher mean sequence divergence in the EH population than in the WH.

CONCLUSION: We propose five 'Evolutionary Significant Units' across the blue sheep distribution range based on observed variation in the species' ecological requirements, orography, climatic conditions, and maternal lineages, viz.; Western Himalaya-Pamir plateau (WHPP); Eastern Himalaya-Tibetan plateau (EHTP); Qilian mountains; Helan mountains and Hengduan mountains population. Despite the small sample size, population divergence was observed across the IHR, therefore, we suggest a transboundary, collaborative study on comparative morphology, anatomy, ecology, behaviour, and population genetics using harmonized different genetic markers for identifying the overall taxonomic status of the blue sheep across its range for planning effective conservation strategies.

RevDate: 2022-11-07
CmpDate: 2022-11-07

Zhang M, Zhang C, Hu P, et al (2022)

Comprehensive analysis of mitogenome of native Henan pig breeds with 58 worldwide pig breeds.

Animal genetics, 53(6):803-813.

Mitochondria follow non-Mendelian maternal inheritance, and thus can be used to compare genetic diversity and infer the expansion and migration between animal populations. Based on the mitochondrial DNA sequences of 58 pig breeds from Asia, Europe, Oceania, and America, we observed a distinct division of Eurasian pig species into two main Haplogroups (A and B), with the exception of the Berkshire and Yorkshire breeds. Oceanian pigs were much more similar to European and American pigs in Haplogroup A. Additionally, native Chinese pigs exhibited the most abundant genetic polymorphisms and occupied the centre of Haplogroup B. Miyazaki (Japan) and Siberia (Russia) are two distant and disconnected regions; however, most pigs from these regions were clustered into a subcluster, while native pigs from Korea clustered into a second subcluster. This study is the first to report that pigs from Thailand and Vietnam had haplotypes similar to those of Henan, where the earliest evidence of domestic pigs was found from the Yellow River Basin of North China. Local Henan pig breeds are related to many Asian breeds while still having their own mutation identity, such as g.314 delins T>AC/AT/C of the 12S rRNA gene in Yuxi. Some pigs from Palawan, Itbayat, and Batan Islands of the Philippines and Lanyu Island of China were distinct from other Asian pigs and clustered together into Haplogroup C. These findings show that the complexity of domestication of worldwide pig breeds and mitochondria could reflect genetic communication between pig breeds due to geographical proximity and human activities.

RevDate: 2022-11-04
CmpDate: 2022-11-04

Wei W, Schon KR, Elgar G, et al (2022)

Nuclear-embedded mitochondrial DNA sequences in 66,083 human genomes.

Nature, 611(7934):105-114.

DNA transfer from cytoplasmic organelles to the cell nucleus is a legacy of the endosymbiotic event-the majority of nuclear-mitochondrial segments (NUMTs) are thought to be ancient, preceding human speciation1-3. Here we analyse whole-genome sequences from 66,083 people-including 12,509 people with cancer-and demonstrate the ongoing transfer of mitochondrial DNA into the nucleus, contributing to a complex NUMT landscape. More than 99% of individuals had at least one of 1,637 different NUMTs, with 1 in 8 individuals having an ultra-rare NUMT that is present in less than 0.1% of the population. More than 90% of the extant NUMTs that we evaluated inserted into the nuclear genome after humans diverged from apes. Once embedded, the sequences were no longer under the evolutionary constraint seen within the mitochondrion, and NUMT-specific mutations had a different mutational signature to mitochondrial DNA. De novo NUMTs were observed in the germline once in every 104 births and once in every 103 cancers. NUMTs preferentially involved non-coding mitochondrial DNA, linking transcription and replication to their origin, with nuclear insertion involving multiple mechanisms including double-strand break repair associated with PR domain zinc-finger protein 9 (PRDM9) binding. The frequency of tumour-specific NUMTs differed between cancers, including a probably causal insertion in a myxoid liposarcoma. We found evidence of selection against NUMTs on the basis of size and genomic location, shaping a highly heterogenous and dynamic human NUMT landscape.

RevDate: 2022-11-03

Zhao B, Gao S, Zhao M, et al (2022)

Mitochondrial genomic analyses provide new insights into the "missing" atp8 and adaptive evolution of Mytilidae.

BMC genomics, 23(1):738.

BACKGROUND: Mytilidae, also known as marine mussels, are widely distributed in the oceans worldwide. Members of Mytilidae show a tremendous range of ecological adaptions, from the species distributed in freshwater to those that inhabit in deep-sea. Mitochondria play an important role in energy metabolism, which might contribute to the adaptation of Mytilidae to different environments. In addition, some bivalve species are thought to lack the mitochondrial protein-coding gene ATP synthase F0 subunit 8. Increasing studies indicated that the absence of atp8 may be caused by annotation difficulties for atp8 gene is characterized by highly divergent, variable length.

RESULTS: In this study, the complete mitochondrial genomes of three marine mussels (Xenostrobus securis, Bathymodiolus puteoserpentis, Gigantidas vrijenhoeki) were newly assembled, with the lengths of 14,972 bp, 20,482, and 17,786 bp, respectively. We annotated atp8 in the sequences that we assembled and the sequences lacking atp8. The newly annotated atp8 sequences all have one predicted transmembrane domain, a similar hydropathy profile, as well as the C-terminal region with positively charged amino acids. Furthermore, we reconstructed the phylogenetic trees and performed positive selection analysis. The results showed that the deep-sea bathymodiolines experienced more relaxed evolutionary constraints. And signatures of positive selection were detected in nad4 of Limnoperna fortunei, which may contribute to the survival and/or thriving of this species in freshwater.

CONCLUSIONS: Our analysis supported that atp8 may not be missing in the Mytilidae. And our results provided evidence that the mitochondrial genes may contribute to the adaptation of Mytilidae to different environments.

RevDate: 2022-11-02

Picard M, OS Shirihai (2022)

Mitochondrial signal transduction.

Cell metabolism, 34(11):1620-1653.

The analogy of mitochondria as powerhouses has expired. Mitochondria are living, dynamic, maternally inherited, energy-transforming, biosynthetic, and signaling organelles that actively transduce biological information. We argue that mitochondria are the processor of the cell, and together with the nucleus and other organelles they constitute the mitochondrial information processing system (MIPS). In a three-step process, mitochondria (1) sense and respond to both endogenous and environmental inputs through morphological and functional remodeling; (2) integrate information through dynamic, network-based physical interactions and diffusion mechanisms; and (3) produce output signals that tune the functions of other organelles and systemically regulate physiology. This input-to-output transformation allows mitochondria to transduce metabolic, biochemical, neuroendocrine, and other local or systemic signals that enhance organismal adaptation. An explicit focus on mitochondrial signal transduction emphasizes the role of communication in mitochondrial biology. This framework also opens new avenues to understand how mitochondria mediate inter-organ processes underlying human health.

RevDate: 2022-11-02

McGlynn SE, Perkins G, Sim MS, et al (2022)

A Cristae-Like Microcompartment in Desulfobacterota.

mBio [Epub ahead of print].

Some Alphaproteobacteria contain intracytoplasmic membranes (ICMs) and proteins homologous to those responsible for the mitochondrial cristae, an observation which has given rise to the hypothesis that the Alphaproteobacteria endosymbiont had already evolved cristae-like structures and functions. However, our knowledge of microbial fine structure is still limited, leaving open the possibility of structurally homologous ICMs outside the Alphaproteobacteria. Here, we report on the detailed characterization of lamellar cristae-like ICMs in environmental sulfate-reducing Desulfobacterota that form syntrophic partnerships with anaerobic methane-oxidizing (ANME) archaea. These structures are junction-bound to the cytoplasmic membrane and resemble the form seen in the lamellar cristae of opisthokont mitochondria. Extending these observations, we also characterized similar structures in Desulfovibrio carbinolicus, a close relative of the magnetotactic D. magneticus, which does not contain magnetosomes. Despite a remarkable structural similarity, the key proteins involved in cristae formation have not yet been identified in Desulfobacterota, suggesting that an analogous, but not a homologous, protein organization system developed during the evolution of some members of Desulfobacterota. IMPORTANCE Working with anaerobic consortia of methane oxidizing ANME archaea and their sulfate-reducing bacterial partners recovered from deep sea sediments and with the related sulfate-reducing bacterial isolate D. carbinolicus, we discovered that their intracytoplasmic membranes (ICMs) appear remarkably similar to lamellar cristae. Three-dimensional electron microscopy allowed for the novel analysis of the nanoscale attachment of ICMs to the cytoplasmic membrane, and these ICMs are structurally nearly identical to the crista junction architecture seen in metazoan mitochondria. However, the core junction-forming proteins must be different. The outer membrane vesicles were observed to bud from syntrophic Desulfobacterota, and darkly stained granules were prominent in both Desulfobacterota and D. carbinolicus. These findings expand the taxonomic breadth of ICM-producing microorganisms and add to our understanding of three-dimensional microbial fine structure in environmental microorganisms.

RevDate: 2022-10-28
CmpDate: 2022-10-28

Liu Q, Zhang L, Zou Y, et al (2022)

Modulating p-AMPK/mTOR Pathway of Mitochondrial Dysfunction Caused by MTERF1 Abnormal Expression in Colorectal Cancer Cells.

International journal of molecular sciences, 23(20): pii:ijms232012354.

Human mitochondrial transcription termination factor 1 (MTERF1) has been demonstrated to play an important role in mitochondrial gene expression regulation. However, the molecular mechanism of MTERF1 in colorectal cancer (CRC) remains largely unknown. Here, we found that MTERF1 expression was significantly increased in colon cancer tissues compared with normal colorectal tissue by Western blotting, immunohistochemistry, and tissue microarrays (TMA). Overexpression of MTERF1 in the HT29 cell promoted cell proliferation, migration, invasion, and xenograft tumor formation, whereas knockdown of MTERF1 in HCT116 cells appeared to be the opposite phenotype to HT29 cells. Furthermore, MTERF1 can increase mitochondrial DNA (mtDNA) replication, transcription, and protein synthesis in colorectal cancer cells; increase ATP levels, the mitochondrial crista density, mitochondrial membrane potential, and oxygen consumption rate (OCR); and reduce the ROS production in colorectal cancer cells, thereby enhancing mitochondrial oxidative phosphorylation (OXPHOS) activity. Mechanistically, we revealed that MTERF1 regulates the AMPK/mTOR signaling pathway in cancerous cell lines, and we also confirmed the involvement of the AMPK/mTOR signaling pathway in both xenograft tumor tissues and colorectal cancer tissues. In summary, our data reveal an oncogenic role of MTERF1 in CRC progression, indicating that MTERF1 may represent a new therapeutic target in the future.

RevDate: 2022-10-25

Guo C, Wang A, Cheng H, et al (2022)

New imaging instrument in animal models: two-photon miniature microscope and large field of view miniature microscope for freely behaving animals.

Journal of neurochemistry [Epub ahead of print].

Over the past decade, novel optical imaging tools have been developed for imaging neuronal activities along with the evolution of fluorescence indicators with brighter expression and higher sensitivity. Miniature microscopes, as revolutionary approaches, enable the imaging of large populations of neuron ensembles in freely behaving rodents and mammals, which allow exploring the neural basis of behaviors. Recent progress on two-photon miniature microscopes and mesoscale single-photon miniature microscopes further expands those affordable methods to navigate neural activities during naturalistic behaviors. In this review article, two-photon miniature microscopy techniques are summarized historically from the first documented attempt to the latest ones, and comparisons are made. The driving force behind and their potential for neuroscientific inquiries are also discussed. Current progress in terms of the mesoscale, i.e., the large field-of-view miniature microscopy technique, is addressed as well. Then, pipelines for registering single cells from the data of two-photon and large field-of-view miniature microscopes are discussed. Finally, we present the potential evolution of the techniques.

RevDate: 2022-10-25

Fan L, Wu D, Goremykin V, et al (2022)

Reply to: Phylogenetic affiliation of mitochondria with Alpha-II and Rickettsiales is an artefact.

RevDate: 2022-10-24

Bi R, Li Y, Xu M, et al (2022)

Direct evidence of CRISPR-Cas9-mediated mitochondrial genome editing.

Innovation (Cambridge (Mass.)), 3(6):100329 pii:S2666-6758(22)00125-4.

Pathogenic mitochondrial DNA (mtDNA) mutations can cause a variety of human diseases. The recent development of genome-editing technologies to manipulate mtDNA, such as mitochondria-targeted DNA nucleases and base editors, offer a promising way for curing mitochondrial diseases caused by mtDNA mutations. The CRISPR-Cas9 system is a widely used tool for genome editing; however, its application in mtDNA editing is still under debate. In this study, we developed a mito-Cas9 system by adding the mitochondria-targeted sequences and 3' untranslated region of nuclear-encoded mitochondrial genes upstream and downstream of the Cas9 gene, respectively. We confirmed that the mito-Cas9 system was transported into mitochondria and enabled knockin of exogenous single-stranded DNA oligonucleotides (ssODNs) into mtDNA based on proteinase and DNase protection assays. Successful knockin of exogenous ssODNs into mtDNA was further validated using polymerase chain reaction-free third-generation sequencing technology. We also demonstrated that RS-1, an agonist of RAD51, significantly increased knockin efficiency of the mito-Cas9 system. Collectively, we provide direct evidence that mtDNA can be edited using the CRISPR-Cas9 system. The mito-Cas9 system could be optimized as a promising approach for the treatment of mitochondrial diseases caused by pathogenic mtDNA mutations, especially those with homoplasmic mtDNA mutations.

RevDate: 2022-10-19

Zhang K, Li J, Li G, et al (2022)

Compensatory genetic and transcriptional cytonuclear coordination in allopolyploid lager yeast (Saccharomyces pastorianus).

Molecular biology and evolution pii:6763671 [Epub ahead of print].

Cytonuclear coordination between biparental nuclear genomes and uniparental cytoplasmic organellar genomes in plants is often resolved by genetic and transcriptional cytonuclear responses. Whether this mechanism also acts in allopolyploid members of other kingdoms is not clear. Additionally, cytonuclear coordination of interleaved allopolyploid cells/individuals within the same population is underexplored. The yeast Saccharomyces pastorianus provides the opportunity to explore cytonuclear coevolution during different growth stages and from novel dimensions. Using S. pastorianus cells from multiple growth stages in the same environment, we show that nuclear mitochondria-targeted (NMT) genes have undergone both asymmetric gene conversion and growth stage-specific biased expression favoring genes from the mitochondrial genome donor (S. eubayanus). Our results suggest that cytonuclear coordination in allopolyploid lager yeast species entails an orchestrated and compensatory genetic and transcriptional evolutionary regulatory shift. The common as well as unique properties of cytonuclear coordination underlying allopolyploidy between unicellular yeasts and higher plants offers novel insights into mechanisms of cytonuclear evolution associated with allopolyploid speciation.

RevDate: 2022-10-20
CmpDate: 2022-10-20

Marx C, Marx-Blümel L, Sonnemann J, et al (2023)

Assessment of Mitochondrial Dysfunctions After Sirtuin Inhibition.

Methods in molecular biology (Clifton, N.J.), 2589:269-291.

Posttranslational modifications are important for protein functions and cellular signaling pathways. The acetylation of lysine residues is catalyzed by histone acetyltransferases (HATs) and removed by histone deacetylases (HDACs), with the latter being grouped into four phylogenetic classes. The class III of the HDAC family, the sirtuins (SIRTs), contributes to gene expression, genomic stability, cell metabolism, and tumorigenesis. Thus, several specific SIRT inhibitors (SIRTi) have been developed to target cancer cell proliferation. Here we provide an overview of methods to study SIRT-dependent cell metabolism and mitochondrial functionality. The chapter describes metabolic flux analysis using Seahorse analyzers, methods for normalization of Seahorse data, flow cytometry and fluorescence microscopy to determine the mitochondrial membrane potential, mitochondrial content per cell and mitochondrial network structures, and Western blot analysis to measure mitochondrial proteins.

RevDate: 2022-10-19
CmpDate: 2022-10-19

Tobiasson V, Berzina I, A Amunts (2022)

Structure of a mitochondrial ribosome with fragmented rRNA in complex with membrane-targeting elements.

Nature communications, 13(1):6132.

Mitoribosomes of green algae display a great structural divergence from their tracheophyte relatives, with fragmentation of both rRNA and proteins as a defining feature. Here, we report a 2.9 Å resolution structure of the mitoribosome from the alga Polytomella magna harbouring a reduced rRNA split into 13 fragments. We found that the rRNA contains a non-canonical reduced form of the 5S, as well as a permutation of the LSU domain I. The mt-5S rRNA is stabilised by mL40 that is also found in mitoribosomes lacking the 5S, which suggests an evolutionary pathway. Through comparison to other ribosomes with fragmented rRNAs, we observe that the pattern is shared across large evolutionary distances, and between cellular compartments, indicating an evolutionary convergence and supporting the concept of a primordial fragmented ribosome. On the protein level, eleven peripherally associated HEAT-repeat proteins are involved in the binding of 3' rRNA termini, and the structure features a prominent pseudo-trimer of one of them (mL116). Finally, in the exit tunnel, mL128 constricts the tunnel width of the vestibular area, and mL105, a homolog of a membrane targeting component mediates contacts with an inner membrane bound insertase. Together, the structural analysis provides insight into the evolution of the ribosomal machinery in mitochondria.

RevDate: 2022-10-17

Giuditta A, Zucconi GG, A Sadile (2022)

Brain Metabolic DNA: A Long Story and Some Conclusions.

Molecular neurobiology [Epub ahead of print].

We have previously outlined the main properties of brain metabolic DNA (BMD) and its involvement in circadian oscillations, learning, and post-trial sleep. The presence of BMD in certain subcellular fractions and their behavior in cesium gradients have suggested that BMD originates from cytoplasmic reverse transcription and subsequently acquires a double-stranded configuration. More recently, it has been reported that some DNA sequences of cytoplasmic BMD in learning mice are different from that of the control animals. Furthermore, BMD is located in vicinity of the genes involved in different modifications of synaptic activity, suggesting that BMD may contribute to the brain's response to the changing environment. The present review outlines recent data with a special emphasis on reverse transcription of BMD that may recapitulate the molecular events at the time of the "RNA world" by activating mitochondrial telomerase and generating RNA templates from mitochondrial transcripts. The latter unexpected role of mitochondria is likely to promote a better understanding of mitochondrial contribution to cellular interactions and eukaryotic evolution. An initial step regards the role of human mitochondria in embryonic BMD synthesis, which is exclusively of maternal origin. In addition, mitochondrial transcripts involved in reverse transcription of BMD might possibly reveal unexpected features elucidating mitochondrial involvement in cancer events and neurodegenerative disorders.

RevDate: 2022-10-13

Loiacono FV, Walther D, Seeger S, et al (2022)

Emergence of novel RNA editing sites by changes in the binding affinity of a conserved PPR protein.

Molecular biology and evolution pii:6760358 [Epub ahead of print].

RNA editing converts cytidines to uridines in plant organellar transcripts. Editing typically restores codons for conserved amino acids. During evolution, specific C-to-U editing sites can be lost from some plant lineages by genomic C-to-T mutations. By contrast, the emergence of novel editing sites is less well documented. Editing sites are recognized by pentatricopeptide repeat (PPR) proteins with high specificity. RNA recognition by PPR proteins is partially predictable, but prediction is often inadequate for PPRs involved in RNA editing. Here we have characterized evolution and recognition of a recently gained editing site. We demonstrate that changes in the RNA recognition motifs that are not explainable with the current PPR code allow an ancient PPR protein, QED1, to uniquely target the ndhB-291 site in Brassicaceae. When expressed in tobacco, the Arabidopsis QED1 edits 33 high-confident off-target sites in chloroplasts and mitochondria causing a spectrum of mutant phenotypes. By manipulating the relative expression levels of QED1 and ndhB-291, we show that the target specificity of the PPR protein depends on the RNA:protein ratio. Finally, our data suggest that the low expression levels of PPR proteins are necessary to ensure the specificity of editing site selection and prevent deleterious off-target editing.

RevDate: 2022-10-13

Chen L, A Kashina (2022)

Arginylation Regulates Cytoskeleton Organization and Cell Division and Affects Mitochondria in Fission Yeast.

Molecular and cellular biology [Epub ahead of print].

Protein arginylation mediated by arginyltransferase Ate1 is a posttranslational modification of emerging importance implicated in the regulation of mammalian embryogenesis, the cardiovascular system, tissue morphogenesis, cell migration, neurodegeneration, cancer, and aging. Ate1 deletion results in embryonic lethality in mice but does not affect yeast viability, making yeast an ideal system to study the molecular pathways regulated by arginylation. Here, we conducted a global analysis of cytoskeleton-related arginylation-dependent phenotypes in Schizosaccharomyces pombe, a fission yeast species that shares many fundamental features of higher eukaryotic cells. Our studies revealed roles of Ate1 in cell division, cell polarization, organelle transport, and interphase cytoskeleton organization and dynamics. We also found a role of Ate1 in mitochondria morphology and maintenance. Furthermore, targeted mass spectrometry analysis of the total Sc. pombe arginylome identified a number of arginylated proteins, including those that play direct roles in these processes; lack of their arginylation may be responsible for ate1-knockout phenotypes. Our work outlines global biological processes potentially regulated by arginylation and paves the way to unraveling the functions of protein arginylation that are conserved at multiple levels of evolution and potentially constitute the primary role of this modification in vivo.

RevDate: 2022-10-11

Liu S, Storti M, Finazzi G, et al (2022)

A metabolic, phylogenomic and environmental atlas of diatom plastid transporters from the model species Phaeodactylum.

Frontiers in plant science, 13:950467.

Diatoms are an important group of algae, contributing nearly 40% of total marine photosynthetic activity. However, the specific molecular agents and transporters underpinning the metabolic efficiency of the diatom plastid remain to be revealed. We performed in silico analyses of 70 predicted plastid transporters identified by genome-wide searches of Phaeodactylum tricornutum. We considered similarity with Arabidopsis thaliana plastid transporters, transcriptional co-regulation with genes encoding core plastid metabolic pathways and with genes encoded in the mitochondrial genomes, inferred evolutionary histories using single-gene phylogeny, and environmental expression trends using Tara Oceans meta-transcriptomics and meta-genomes data. Our data reveal diatoms conserve some of the ion, nucleotide and sugar plastid transporters associated with plants, such as non-specific triose phosphate transporters implicated in the transport of phosphorylated sugars, NTP/NDP and cation exchange transporters. However, our data also highlight the presence of diatom-specific transporter functions, such as carbon and amino acid transporters implicated in intricate plastid-mitochondria crosstalk events. These confirm previous observations that substrate non-specific triose phosphate transporters (TPT) may exist as principal transporters of phosphorylated sugars into and out of the diatom plastid, alongside suggesting probable agents of NTP exchange. Carbon and amino acid transport may be related to intricate metabolic plastid-mitochondria crosstalk. We additionally provide evidence from environmental meta-transcriptomic/meta- genomic data that plastid transporters may underpin diatom sensitivity to ocean warming, and identify a diatom plastid transporter (J43171) whose expression may be positively correlated with temperature.

RevDate: 2022-10-11
CmpDate: 2022-10-10

Nofrianto AB, Lawelle SA, Mokodongan DF, et al (2022)

Ancient Admixture in Freshwater Halfbeaks of the Genus Nomorhamphus in Southeast Sulawesi.

Zoological science, 39(5):453-458.

Freshwater halfbeaks of the genus Nomorhamphus (Zenarchopteridae) uniquely diversified on Sulawesi Island, where tectonic movements have been very active since the Pliocene. Most species of this genus have quite limited distributions, which indicates that geographic isolations have contributed to their diversification. In this study, we demonstrated that secondary contacts and resultant admixtures between long-isolated species/populations may have also been important. We found that the mitochondrial phylogeny of a group of Nomorhamphus in Southeast Sulawesi was discordant with the nuclear phylogeny. Most notably, individuals in the upper and lower streams of the Moramo River, a small river in this region, clustered with each other in the mitochondrial phylogeny but not in the nuclear phylogeny; in the latter, the lower-stream individuals formed a clade with individuals in the Anduna River, a different river with no present water connection to the Moramo River. Phylogenetic network and population structure analyses using genomic data obtained from RNA-seq revealed that the lower-stream Moramo population admixed with the upper-stream Moramo lineage in ancient times. These findings indicate that the observed mito-nuclear discordance was caused by mitochondrial introgression and not incomplete lineage sorting. The phylogenetic network also revealed several other admixtures between ancient lineages. Repeated admixtures were also evidenced by topological incongruence in population trees estimated using the RNA-seq data. We propose that activities of many fault systems dissecting Southeast Sulawesi caused repeated secondary contact.

RevDate: 2022-10-09

Mondal S, SP Singh (2022)

New insights on thioredoxins (Trxs) and glutaredoxins (Grxs) by in silico amino acid sequence, phylogenetic and comparative structural analyses in organisms of three domains of life.

Heliyon, 8(10):e10776.

Thioredoxins (Trxs) and Glutaredoxins (Grxs) regulate several cellular processes by controlling the redox state of their target proteins. Trxs and Grxs belong to thioredoxin superfamily and possess characteristic Trx/Grx fold. Several phylogenetic, biochemical and structural studies have contributed to our overall understanding of Trxs and Grxs. However, comparative study of closely related Trxs and Grxs in organisms of all domains of life was missing. Here, we conducted in silico comparative structural analysis combined with amino acid sequence and phylogenetic analyses of 65 Trxs and 88 Grxs from 12 organisms of three domains of life to get insights into evolutionary and structural relationship of two proteins. Outcomes suggested that despite diversity in their amino acids composition in distantly related organisms, both Trxs and Grxs strictly conserved functionally and structurally important residues. Also, position of these residues was highly conserved in all studied Trxs and Grxs. Notably, if any substitution occurred during evolution, preference was given to amino acids having similar chemical properties. Trxs and Grxs were found more different in eukaryotes than prokaryotes due to altered helical conformation. The surface of Trxs was negatively charged, while Grxs surface was positively charged, however, the active site was constituted by uncharged amino acids in both proteins. Also, phylogenetic analysis of Trxs and Grxs in three domains of life supported endosymbiotic origins of chloroplast and mitochondria, and suggested their usefulness in molecular systematics. We also report previously unknown catalytic motifs of two proteins, and discuss in detail about effect of abovementioned parameters on overall structural and functional diversity of Trxs and Grxs.

RevDate: 2022-10-20
CmpDate: 2022-10-20

Moreno ACR, Olean-Oliveira A, Olean-Oliveira T, et al (2022)

Resistance training prevents damage to the mitochondrial function of the skeletal muscle of rats exposed to secondary cigarette smoke.

Life sciences, 309:121017.

AIM: To analyze the consumption of oxygen and to quantify the mitochondrial respiratory chain proteins (OXPHOS) in the gastrocnemius muscle of rats exposed to cigarette smoke and/or RT practitioners.

MAIN METHODS: Wistar rats were divided into groups: Control (C), Smoker (S), Exercise (E) and Exercise Smoker (ES). Groups F and ES were exposed to the smoke of 4 cigarettes for 30 min, 2× a day, 5× a week, for 16 weeks. Groups E and ES performed four climbs with progressive load, 1× per day, 5× per week, for 16 weeks. The gastrocnemius muscle was collected for analysis of OXPHOS content and oxygen consumption. Groups S (vs. C) and ES (vs. C and E) showed lower body weight gain when observing the evolution curve.

KEY FINDINGS: The S rats showed a reduction in the NDUFB8 proteins of complex 1, SDHB of complex 2, MTC01 of complex 4 and ATP5A of complex 5 (ATP Synthase) compared to Group C. Additionally, S rats also showed increased consumption of O2 in Basal, Leak, Complex I and I/II combined measures compared to the other groups, suggesting that the activity of the mitochondria of these animals increased in terms of coupling and uncoupling parameters.

SIGNIFICANCE: Our data suggest that exposure to cigarette smoke for 16 weeks is capable of causing impairment of mitochondrial function with reduced expression of respiratory chain proteins in skeletal muscle. However, the RT was effective in preventing impairment of mitochondrial function in the skeletal muscle of rats exposed to secondary cigarette smoke.

RevDate: 2022-10-11
CmpDate: 2022-10-04

Xiao S, Xing J, Nie T, et al (2022)

Comparative analysis of mitochondrial genomes of maize CMS-S subtypes provides new insights into male sterility stability.

BMC plant biology, 22(1):469.

BACKGROUND: Cytoplasmic male sterility (CMS) is a trait of economic importance in the production of hybrid seeds. In CMS-S maize, exerted anthers appear frequently in florets of field-grown female populations where only complete male-sterile plants were expected. It has been reported that these reversions are associated with the loss of sterility-conferring regions or other rearrangements in the mitochondrial genome. However, the relationship between mitochondrial function and sterility stability is largely unknown.

RESULTS: In this study, we determined the ratio of plants carrying exerted anthers in the population of two CMS-S subtypes. The subtype with a high ratio of exerted anthers was designated as CMS-Sa, and the other with low ratio was designated as CMS-Sb. Through next-generation sequencing, we assembled and compared mitochondrial genomes of two CMS-S subtypes. Phylogenetic analyses revealed strong similarities between the two mitochondrial genomes. The sterility-associated regions, S plasmids, and terminal inverted repeats (TIRs) were intact in both genomes. The two subtypes maintained high transcript levels of the sterility gene orf355 in anther tissue. Most of the functional genes/proteins were identical at the nucleotide sequence and amino acid sequence levels in the two subtypes, except for NADH dehydrogenase subunit 1 (nad1). In the mitochondrial genome of CMS-Sb, a 3.3-kilobase sequence containing nad1-exon1 was absent from the second copy of the 17-kb repeat region. Consequently, we detected two copies of nad1-exon1 in CMS-Sa, but only one copy in CMS-Sb. During pollen development, nad1 transcription and mitochondrial biogenesis were induced in anthers of CMS-Sa, but not in those of CMS-Sb. We suggest that the impaired mitochondrial function in the anthers of CMS-Sb is associated with its more stable sterility.

CONCLUSIONS: Comprehensive analyses revealed diversity in terms of the copy number of the mitochondrial gene nad1-exon1 between two subtypes of CMS-S maize. This difference in copy number affected the transcript levels of nad1 and mitochondrial biogenesis in anther tissue, and affected the reversion rate of CMS-S maize. The results of this study suggest the involvement of mitochondrial robustness in modulation of sterility stability in CMS-S maize.

RevDate: 2022-09-28

Ikeda A, Imai Y, N Hattori (2022)

Neurodegeneration-associated mitochondrial proteins, CHCHD2 and CHCHD10-what distinguishes the two?.

Frontiers in cell and developmental biology, 10:996061.

Coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2) and Coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10) are mitochondrial proteins that are thought to be genes which duplicated during evolution and are the causative genes for Parkinson's disease and amyotrophic lateral sclerosis/frontotemporal lobe dementia, respectively. CHCHD2 forms a heterodimer with CHCHD10 and a homodimer with itself, both of which work together within the mitochondria. Various pathogenic and disease-risk variants have been identified; however, how these mutations cause neurodegeneration in specific diseases remains a mystery. This review focuses on important new findings published since 2019 and discusses avenues to solve this mystery.

RevDate: 2022-09-28

Govindharaj GP, Babu SB, Choudhary JS, et al (2022)

Genome Organization and Comparative Evolutionary Mitochondriomics of Brown Planthopper, Nilaparvata lugens Biotype 4 Using Next Generation Sequencing (NGS).

Life (Basel, Switzerland), 12(9):.

Nilaparvata lugens is the main rice pest in India. Until now, the Indian N. lugens mitochondrial genome has not been sequenced, which is a very important basis for population genetics and phylogenetic evolution studies. An attempt was made to sequence two examples of the whole mitochondrial genome of N. lugens biotype 4 from the Indian population for the first time. The mitogenomes of N. lugens are 16,072 and 16,081 bp long with 77.50% and 77.45% A + T contents, respectively, for both of the samples. The mitochondrial genome of N. lugens contains 37 genes, including 13 protein-coding genes (PCGs) (cox1-3, atp6, atp8, nad1-6, nad4l, and cob), 22 transfer RNA genes, and two ribosomal RNA (rrnS and rrnL) subunits genes, which are typical of metazoan mitogenomes. However, both samples of N. lugens mitogenome in the present study retained one extra copy of the trnC gene. Additionally, we also found 93 bp lengths for the atp8 gene in both of the samples, which were 60-70 bp less than that of the other sequenced mitogenomes of hemipteran insects. The phylogenetic analysis of the 19 delphacids mitogenome dataset yielded two identical topologies when rooted with Ugyops sp. in one clade, and the remaining species formed another clade with P. maidis and M. muiri being sisters to the remaining species. Further, the genus Nilaparvata formed a separate subclade with the other genera (Sogatella, Laodelphax, Changeondelphax, and Unkanodes) of Delphacidae. Additionally, the relationship among the biotypes of N. lugens was recovered as the present study samples (biotype-4) were separated from the three biotypes reported earlier. The present study provides the reference mitogenome for N. lugens biotype 4 that may be utilized for biotype differentiation and molecular-aspect-based future studies of N. lugens.

RevDate: 2022-09-17

Giannakis K, Arrowsmith SJ, Richards L, et al (2022)

Evolutionary inference across eukaryotes identifies universal features shaping organelle gene retention.

Cell systems pii:S2405-4712(22)00351-9 [Epub ahead of print].

Mitochondria and plastids power complex life. Why some genes and not others are retained in their organelle DNA (oDNA) genomes remains a debated question. Here, we attempt to identify the properties of genes and associated underlying mechanisms that determine oDNA retention. We harness over 15k oDNA sequences and over 300 whole genome sequences across eukaryotes with tools from structural biology, bioinformatics, machine learning, and Bayesian model selection. Previously hypothesized features, including the hydrophobicity of a protein product, and less well-known features, including binding energy centrality within a protein complex, predict oDNA retention across eukaryotes, with additional influences of nucleic acid and amino acid biochemistry. Notably, the same features predict retention in both organelles, and retention models learned from one organelle type quantitatively predict retention in the other, supporting the universality of these features-which also distinguish gene profiles in more recent, independent endosymbiotic relationships. A record of this paper's transparent peer review process is included in the supplemental information.

RevDate: 2022-09-28
CmpDate: 2022-09-28

Lesch E, Schilling MT, Brenner S, et al (2022)

Plant mitochondrial RNA editing factors can perform targeted C-to-U editing of nuclear transcripts in human cells.

Nucleic acids research, 50(17):9966-9983.

RNA editing processes are strikingly different in animals and plants. Up to thousands of specific cytidines are converted into uridines in plant chloroplasts and mitochondria whereas up to millions of adenosines are converted into inosines in animal nucleo-cytosolic RNAs. It is unknown whether these two different RNA editing machineries are mutually incompatible. RNA-binding pentatricopeptide repeat (PPR) proteins are the key factors of plant organelle cytidine-to-uridine RNA editing. The complete absence of PPR mediated editing of cytosolic RNAs might be due to a yet unknown barrier that prevents its activity in the cytosol. Here, we transferred two plant mitochondrial PPR-type editing factors into human cell lines to explore whether they could operate in the nucleo-cytosolic environment. PPR56 and PPR65 not only faithfully edited their native, co-transcribed targets but also different sets of off-targets in the human background transcriptome. More than 900 of such off-targets with editing efficiencies up to 91%, largely explained by known PPR-RNA binding properties, were identified for PPR56. Engineering two crucial amino acid positions in its PPR array led to predictable shifts in target recognition. We conclude that plant PPR editing factors can operate in the entirely different genetic environment of the human nucleo-cytosol and can be intentionally re-engineered towards new targets.

RevDate: 2022-09-15
CmpDate: 2022-09-15

Zhou S, He LI, Ma S, et al (2022)

Taxonomic status of Rana nigromaculata mongolia and the validity of Pelophylax tenggerensis (Anura, Ranidae).

Zootaxa, 5165(4):486-500.

The Black-spotted Pond Frog, Pelophylax nigromaculatus, is widely distributed across mainland China, Korean Peninsula, and Japan. The taxonomic relationships among P. n. nigromaculatus, Rana nigromaculata mongolia (sensu P. n. mongolicus), and P. tenggerensis have long been ambiguous. Here we examine the topotype specimens of P. tenggerensis and R. n. mongolia, and provide phylogenic analyses based on four mitochondrial DNA sequences. The combined evidences from morphology and molecular phylogeny have shown the distinct specific-level of P. n. mongolicus that distant from P. nigromaculatus, while indicating the homogeneity between P. n. mongolicus and P. tenggerensis. Thus, we suggest elevating P. n. mongolicus as a full species Pelophylax mongolicus comb. nov., and place P. tenggerensis to be a secondary synonym of P. mongolicus comb. nov.

RevDate: 2022-09-25
CmpDate: 2022-09-13

Ba Q, Hei Y, Dighe A, et al (2022)

Proteotype coevolution and quantitative diversity across 11 mammalian species.

Science advances, 8(36):eabn0756.

Evolutionary profiling has been largely limited to the nucleotide level. Using consistent proteomic methods, we quantified proteomic and phosphoproteomic layers in fibroblasts from 11 common mammalian species, with transcriptomes as reference. Covariation analysis indicates that transcript and protein expression levels and variabilities across mammals remarkably follow functional role, with extracellular matrix-associated expression being the most variable, demonstrating strong transcriptome-proteome coevolution. The biological variability of gene expression is universal at both interindividual and interspecies scales but to a different extent. RNA metabolic processes particularly show higher interspecies versus interindividual variation. Our results further indicate that while the ubiquitin-proteasome system is strongly conserved in mammals, lysosome-mediated protein degradation exhibits remarkable variation between mammalian lineages. In addition, the phosphosite profiles reveal a phosphorylation coevolution network independent of protein abundance.

RevDate: 2022-09-20
CmpDate: 2022-09-13

Wang S, H Luo (2022)

Estimating the Divergence Times of Alphaproteobacteria Based on Mitochondrial Endosymbiosis and Eukaryotic Fossils.

Methods in molecular biology (Clifton, N.J.), 2569:95-116.

Alphaproteobacteria is one of the most abundant bacterial lineages that successfully colonize diverse marine and terrestrial environments on Earth. In addition, many alphaproteobacterial lineages have established close association with eukaryotes. This makes Alphaproteobacteria a promising system to test the link between the emergence of ecologically important bacteria and related geological events and the co-evolution between symbiotic bacteria and their hosts. Understanding the timescale of evolution of Alphaproteobacteria is key to testing these hypotheses, which is limited by the scarcity of bacterial fossils, however. Based on the mitochondrial endosymbiosis which posits that the mitochondrion originated from an alphaproteobacterial lineage, we propose a new strategy to estimate the divergence times of lineages within the Alphaproteobacteria by leveraging the fossil records of eukaryotes. In this chapter, we describe the workflow of the mitochondria-based method to date Alphaproteobacteria evolution by detailing the software, methods, and commands used for each step. Visualization of data and results is also described. We also provide related notes with background information and alternative options. All codes used to build this protocol are made available to the public, and we strive to make this protocol user-friendly in particular to microbiologists with limited practical skills in bioinformatics.

RevDate: 2022-09-02

Khan K, O Van Aken (2022)

The colonisation of land was a likely driving force for the evolution of mitochondrial retrograde signalling in plants.

Journal of experimental botany pii:6687801 [Epub ahead of print].

Most retrograde signalling research in plants was performed using Arabidopsis, so an evolutionary perspective on mitochondrial retrograde regulation (MRR) is largely missing. Here, we used phylogenetics to track the evolutionary origins of plant MRR-regulators. In all cases, the gene families can be traced to ancestral green algae or earlier. However, the specific subfamilies containing plant MRR-regulators in many cases arose during the transition to land. NAC transcription factors with C-terminal transmembrane domains, as observed in key MRR-regulator ANAC017, can first be observed in non-vascular mosses, and close homologs to ANAC017 can be found in seed plants. Cyclin-dependent kinases (CDKs) are common to eukaryotes, but E-type CDKs that regulate MRR also diverged in conjunction with plant colonization of land. AtWRKY15 can be traced to the earliest land plants, while AtWRKY40 only arose in Angiosperms and AtWRKY63 even more recently in Brassicaceae. Apetala 2 (AP2) transcription factors are traceable to algae, but the ABI4-type again only appeared in seed plants. This strongly suggests that the transition to land was a major driver for developing plant MRR pathways, while additional fine-tunings have appeared in seed plants or later. Finally, we discuss how MRR may have contributed to facing the specific challenges that early land plants faced during terrestrialization.

RevDate: 2022-09-08
CmpDate: 2022-09-08

Monsanto DM, Main DC, Janion-Scheepers C, et al (2022)

Mitogenome selection in the evolution of key ecological strategies in the ancient hexapod class Collembola.

Scientific reports, 12(1):14810.

A longstanding question in evolutionary biology is how natural selection and environmental pressures shape the mitochondrial genomic architectures of organisms. Mitochondria play a pivotal role in cellular respiration and aerobic metabolism, making their genomes functionally highly constrained. Evaluating selective pressures on mitochondrial genes can provide functional and ecological insights into the evolution of organisms. Collembola (springtails) are an ancient hexapod group that includes the oldest terrestrial arthropods in the fossil record, and that are closely associated with soil environments. Of interest is the diversity of habitat stratification preferences (life forms) exhibited by different species within the group. To understand whether signals of positive selection are linked to the evolution of life forms, we analysed 32 published Collembola mitogenomes in a phylomitogenomic framework. We found no evidence that signatures of selection are correlated with the evolution of novel life forms, but rather that mutations have accumulated as a function of time. Our results highlight the importance of nuclear-mitochondrial interactions in the evolution of collembolan life forms and that mitochondrial genomic data should be interpreted with caution, as complex selection signals may complicate evolutionary inferences.

RevDate: 2022-09-26
CmpDate: 2022-09-02

Kuhle B, Hirschi M, Doerfel LK, et al (2022)

Structural basis for shape-selective recognition and aminoacylation of a D-armless human mitochondrial tRNA.

Nature communications, 13(1):5100.

Human mitochondrial gene expression relies on the specific recognition and aminoacylation of mitochondrial tRNAs (mtRNAs) by nuclear-encoded mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs). Despite their essential role in cellular energy homeostasis, strong mutation pressure and genetic drift have led to an unparalleled sequence erosion of animal mtRNAs. The structural and functional consequences of this erosion are not understood. Here, we present cryo-EM structures of the human mitochondrial seryl-tRNA synthetase (mSerRS) in complex with mtRNASer(GCU). These structures reveal a unique mechanism of substrate recognition and aminoacylation. The mtRNASer(GCU) is highly degenerated, having lost the entire D-arm, tertiary core, and stable L-shaped fold that define canonical tRNAs. Instead, mtRNASer(GCU) evolved unique structural innovations, including a radically altered T-arm topology that serves as critical identity determinant in an unusual shape-selective readout mechanism by mSerRS. Our results provide a molecular framework to understand the principles of mito-nuclear co-evolution and specialized mechanisms of tRNA recognition in mammalian mitochondrial gene expression.

RevDate: 2022-08-30
CmpDate: 2022-08-29

Liu Y, Chen C, Wang X, et al (2022)

An Epigenetic Role of Mitochondria in Cancer.

Cells, 11(16):.

Mitochondria are not only the main energy supplier but are also the cell metabolic center regulating multiple key metaborates that play pivotal roles in epigenetics regulation. These metabolites include acetyl-CoA, α-ketoglutarate (α-KG), S-adenosyl methionine (SAM), NAD+, and O-linked beta-N-acetylglucosamine (O-GlcNAc), which are the main substrates for DNA methylation and histone post-translation modifications, essential for gene transcriptional regulation and cell fate determination. Tumorigenesis is attributed to many factors, including gene mutations and tumor microenvironment. Mitochondria and epigenetics play essential roles in tumor initiation, evolution, metastasis, and recurrence. Targeting mitochondrial metabolism and epigenetics are promising therapeutic strategies for tumor treatment. In this review, we summarize the roles of mitochondria in key metabolites required for epigenetics modification and in cell fate regulation and discuss the current strategy in cancer therapies via targeting epigenetic modifiers and related enzymes in metabolic regulation. This review is an important contribution to the understanding of the current metabolic-epigenetic-tumorigenesis concept.

RevDate: 2022-08-30

Wu L, Tong Y, Ayivi SPG, et al (2022)

The Complete Mitochondrial Genomes of Three Sphenomorphinae Species (Squamata: Scincidae) and the Selective Pressure Analysis on Mitochondrial Genomes of Limbless Isopachys gyldenstolpei.

Animals : an open access journal from MDPI, 12(16):.

In order to adapt to diverse habitats, organisms often evolve corresponding adaptive mechanisms to cope with their survival needs. The species-rich family of Scincidae contains both limbed and limbless species, which differ fundamentally in their locomotor demands, such as relying on the movement of limbs or only body swing to move. Locomotion requires energy, and different types of locomotion have their own energy requirements. Mitochondria are the energy factories of living things, which provide a lot of energy for various physiological activities of organisms. Therefore, mitochondrial genomes could be tools to explore whether the limb loss of skinks are selected by adaptive evolution. Isopachys gyldenstolpei is a typical limbless skink. Here, we report the complete mitochondrial genomes of I. gyldenstolpei, Sphenomorphus indicus, and Tropidophorus hainanus. The latter two species were included as limbed comparator species to the limbless I. gyldenstolpei. The results showed that the full lengths of the mitochondrial genomes of I. gyldenstolpei, S. indicus, and T. hainanus were 17,210, 16,944, and 17,001 bp, respectively. Three mitochondrial genomes have typical circular double-stranded structures similar to other reptiles, including 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and the control region. Three mitochondrial genomes obtained in this study were combined with fifteen mitochondrially complete genomes of Scincidae in the NCBI database; the phylogenetic relationship between limbless I. gyldenstolpei and limbed skinks (S. indicus and T. hainanus) is discussed. Through BI and ML trees, Sphenomorphinae and Mabuyinae were monophyletic, while the paraphyly of Scincinae was also recovered. The limbless skink I. gyldenstolpei is closer to the species of Tropidophorus, which has formed a sister group with (T. hainanus + T. hangman). In the mitochondrial genome adaptations between limbless I. gyldenstolpei and limbed skinks, one positively selected site was found in the branch-site model analysis, which was located in ND2 (at position 28, BEB value = 0.907). Through analyzing the protein structure and function of the selected site, we found it was distributed in mitochondrial protein complex I. Positive selection of some mitochondrial genes in limbless skinks may be related to the requirement of energy to fit in their locomotion. Further research is still needed to confirm this conclusion though.

RevDate: 2022-09-08
CmpDate: 2022-09-08

Franzolin GN, Araújo BL, Zatti SA, et al (2022)

Occurrence of the host-parasite system Rhaphiodon vulpinus and Ceratomyxa barbata n. sp. in the two largest watersheds in South America.

Parasitology international, 91:102651.

While around world, species of the genus Ceratomyxa parasite majority marine hosts, growing diversity has been reported in South American freshwater fish. The present study reports Ceratomyxa barbata n. sp. parasitizing the gallbladder of the Rhaphiodon vulpinus fish from the Amazon and La Plata basins. Morphological (light and transmission electron microscopy), molecular (sequencing of small subunit ribosomal DNA - SSU rDNA), and phylogenetic analyses were used to characterize the new species. Worm-like plasmodia endowed with motility were found swimming freely in the bile. The myxospores were elongated, lightly arcuate, with rounded ends and had polar tubules with 3 coils in the polar capsules. Ultrastructural analysis revealed plasmodia composed of an outer cytoplasmic region, where elongated tubular mitochondria, a rough endoplasmic reticulum, sporogonic stages, and a large vacuole occupying the internal area were observed. Phylogenetic analysis, based on SSU rDNA, found that among all South America freshwater Ceratomyxa species, C. barbata n. sp. arises as an earlier divergent species. The present study reveals the occurrence of this host-parasite system (R. vulpinus/C. barbata n. sp.) in the two largest watersheds on the continent.

RevDate: 2022-08-30

Hirakawa Y, Hanawa Y, Yoneda K, et al (2022)

Evolution of a chimeric mitochondrial carbonic anhydrase through gene fusion in a haptophyte alga.

Carbonic anhydrases (CAs) are a universal enzyme family that catalyses the interconversion of carbon dioxide and bicarbonate, and they are localized in most compartments including mitochondria and plastids. Thus far, eight classes of CAs (α-, β-, γ-, δ-, ζ-, η-, θ- and ι-CA) have been characterized. This study reports an interesting gene encoding a fusion protein of β-CA and ι-CA found in the haptophyte Isochrysis galbana. Recombinant protein assays demonstrated that the C-terminal ι-CA region catalyses CO2 hydration, whereas the N-terminal β-CA region no longer exhibits enzymatic activity. Considering that haptophytes generally have mitochondrion-localized β-CAs and plastid-localized ι-CAs, the fusion CA would show an intermediate stage in which mitochondrial β-CA is replaced by ι-CA in a haptophyte species.

RevDate: 2022-08-21
CmpDate: 2022-08-19

Yue J, Lu Q, Ni Y, et al (2022)

Comparative analysis of the plastid and mitochondrial genomes of Artemisia giraldii Pamp.

Scientific reports, 12(1):13931.

Artemisia giraldii Pamp. is an herbaceous plant distributed only in some areas in China. To understand the evolutionary relationship between plastid and mitochondria in A. giraldii, we sequenced and analysed the plastome and mitogenome of A. giraldii on the basis of Illumina and Nanopore DNA sequencing data. The mitogenome was 194,298 bp long, and the plastome was 151,072 bp long. The mitogenome encoded 56 genes, and the overall GC content was 45.66%. Phylogenetic analysis of the two organelle genomes revealed that A. giraldii is located in the same branching position. We found 13 pairs of homologous sequences between the plastome and mitogenome, and only one of them might have transferred from the plastid to the mitochondria. Gene selection pressure analysis in the mitogenome showed that ccmFc, nad1, nad6, atp9, atp1 and rps12 may undergo positive selection. According to the 18 available plastome sequences, we found 17 variant sites in two hypervariable regions that can be used in completely distinguishing 18 Artemisia species. The most interesting discovery was that the mitogenome of A. giraldii was only 43,226 bp larger than the plastome. To the best of our knowledge, this study represented one of the smallest differences between all sequenced mitogenomes and plastomes from vascular plants. The above results can provide a reference for future taxonomic and molecular evolution studies of Asteraceae species.

RevDate: 2022-09-09
CmpDate: 2022-09-09

Holt AG, AM Davies (2022)

A comparison of mtDNA deletion mutant proliferation mechanisms.

Journal of theoretical biology, 551-552:111244.

In this paper we use simulation methods to investigate the proliferation of deletion mutations of mitochondrial DNA in neurons. We simulate three mtDNA proliferation mechanisms, namely, random drift, replicative advantage and vicious cycle. For each mechanism, we investigated the effect mutation rates have on neuron loss within a human host. We also compare heteroplasmy of each mechanism at mutation rates that yield the levels neuron loss that would be associated with dementia. Both random drift and vicious cycle predicted high levels of heteroplasmy, while replicative advantage showed a small number of dominant clones with a low background of heteroplasmy.

RevDate: 2022-09-16
CmpDate: 2022-09-08

Wang G, Wang Y, Ni J, et al (2022)

An MCIA-like complex is required for mitochondrial complex I assembly and seed development in maize.

Molecular plant, 15(9):1470-1487.

During adaptive radiation, mitochondria have co-evolved with their hosts, leading to gain or loss of subunits and assembly factors of respiratory complexes. Plant mitochondrial complex I harbors ∼40 nuclear- and 9 mitochondrial-encoded subunits, and is formed by stepwise assembly during which different intermediates are integrated via various assembly factors. In mammals, the mitochondrial complex I intermediate assembly (MCIA) complex is required for building the membrane arm module. However, plants have lost almost all of the MCIA complex components, giving rise to the hypothesis that plants follow an ancestral pathway to assemble the membrane arm subunits. Here, we characterize a maize crumpled seed mutant, crk1, and reveal by map-based cloning that CRK1 encodes an ortholog of human complex I assembly factor 1, zNDUFAF1, the only evolutionarily conserved MCIA subunit in plants. zNDUFAF1 is localized in the mitochondria and accumulates in two intermediate complexes that contain complex I membrane arm subunits. Disruption of zNDUFAF1 results in severe defects in complex I assembly and activity, a cellular bioenergetic shift to aerobic glycolysis, and mitochondrial vacuolation. Moreover, we found that zNDUFAF1, the putative mitochondrial import inner membrane translocase ZmTIM17-1, and the isovaleryl-coenzyme A dehydrogenase ZmIVD1 interact each other, and could be co-precipitated from the mitochondria and co-migrate in the same assembly intermediates. Knockout of either ZmTIM17-1 or ZmIVD1 could lead to the significantly reduced complex I stability and activity as well as defective seeds. These results suggest that zNDUFAF1, ZmTIM17-1 and ZmIVD1 probably form an MCIA-like complex that is essential for the biogenesis of mitochondrial complex I and seed development in maize. Our findings also imply that plants and mammals recruit MCIA subunits independently for mitochondrial complex I assembly, highlighting the importance of parallel evolution in mitochondria adaptation to their hosts.

RevDate: 2022-08-15
CmpDate: 2022-08-15

Manousaki A, Bagnall J, Spiller D, et al (2022)

Quantitative Characterisation of Low Abundant Yeast Mitochondrial Proteins Reveals Compensation for Haplo-Insufficiency in Different Environments.

International journal of molecular sciences, 23(15):.

The quantification of low abundant membrane-binding proteins such as transcriptional factors and chaperones has proven difficult, even with the most sophisticated analytical technologies. Here, we exploit and optimise the non-invasive Fluorescence Correlation Spectroscopy (FCS) for the quantitation of low abundance proteins, and as proof of principle, we choose two interacting proteins involved in the fission of mitochondria in yeast, Fis1p and Mdv1p. In Saccharomyces cerevisiae, the recruitment of Fis1p and Mdv1p to mitochondria is essential for the scission of the organelles and the retention of functional mitochondrial structures in the cell. We use FCS in single GFP-labelled live yeast cells to quantify the protein abundance in homozygote and heterozygote cells and to investigate the impact of the environments on protein copy number, bound/unbound protein state and mobility kinetics. Both proteins were observed to localise predominantly at mitochondrial structures, with the Mdv1p bound state increasing significantly in a strictly respiratory environment. Moreover, a compensatory mechanism that controls Fis1p abundance upon deletion of one allele was observed in Fis1p but not in Mdv1p, suggesting differential regulation of Fis1p and Mdv1p protein expression.

RevDate: 2022-10-19
CmpDate: 2022-08-09

Silva NM, Kreutzer S, Souleles A, et al (2022)

Ancient mitochondrial diversity reveals population homogeneity in Neolithic Greece and identifies population dynamics along the Danubian expansion axis.

Scientific reports, 12(1):13474.

The aim of the study is to investigate mitochondrial diversity in Neolithic Greece and its relation to hunter-gatherers and farmers who populated the Danubian Neolithic expansion axis. We sequenced 42 mitochondrial palaeogenomes from Greece and analysed them together with European set of 328 mtDNA sequences dating from the Early to the Final Neolithic and 319 modern sequences. To test for population continuity through time in Greece, we use an original structured population continuity test that simulates DNA from different periods by explicitly considering the spatial and temporal dynamics of populations. We explore specific scenarios of the mode and tempo of the European Neolithic expansion along the Danubian axis applying spatially explicit simulations coupled with Approximate Bayesian Computation. We observe a striking genetic homogeneity for the maternal line throughout the Neolithic in Greece whereas population continuity is rejected between the Neolithic and present-day Greeks. Along the Danubian expansion axis, our best-fitting scenario supports a substantial decrease in mobility and an increasing local hunter-gatherer contribution to the gene-pool of farmers following the initial rapid Neolithic expansion. Οur original simulation approach models key demographic parameters rather than inferring them from fragmentary data leading to a better understanding of this important process in European prehistory.

RevDate: 2022-08-23
CmpDate: 2022-08-22

Liao T, Wang S, Stüeken EE, et al (2022)

Phylogenomic Evidence for the Origin of Obligate Anaerobic Anammox Bacteria Around the Great Oxidation Event.

Molecular biology and evolution, 39(8):.

The anaerobic ammonium oxidation (anammox) bacteria can transform ammonium and nitrite to dinitrogen gas, and this obligate anaerobic process accounts for up to half of the global nitrogen loss in surface environments. Yet its origin and evolution, which may give important insights into the biogeochemistry of early Earth, remain enigmatic. Here, we performed a comprehensive phylogenomic and molecular clock analysis of anammox bacteria within the phylum Planctomycetes. After accommodating the uncertainties and factors influencing time estimates, which include implementing both a traditional cyanobacteria-based and a recently developed mitochondria-based molecular dating approach, we estimated a consistent origin of anammox bacteria at early Proterozoic and most likely around the so-called Great Oxidation Event (GOE; 2.32-2.5 Ga) which fundamentally changed global biogeochemical cycles. We further showed that during the origin of anammox bacteria, genes involved in oxidative stress adaptation, bioenergetics, and anammox granules formation were recruited, which might have contributed to their survival on an increasingly oxic Earth. Our findings suggest the rising levels of atmospheric oxygen, which made nitrite increasingly available, was a potential driving force for the emergence of anammox bacteria. This is one of the first studies that link the GOE to the evolution of obligate anaerobic bacteria.

RevDate: 2022-10-11
CmpDate: 2022-10-11

Paulino MG, Rossi PA, Venturini FP, et al (2022)

Liver dysfunction and energy storage mobilization in traíra, Hoplias malabaricus (Teleostei, Erythrinidae) induced by subchronic exposure to toxic cyanobacterial crude extract.

Environmental toxicology, 37(11):2683-2691.

Microcystins (MC) are hepatotoxic for organisms. Liver MC accumulation and structural change are intensely studied, but the functional hepatic enzymes and energy metabolism have received little attention. This study investigated the liver and hepatocyte structures and the activity of key hepatic functional enzymes with emphasis on energetic metabolism changes after subchronic fish exposure to cyanobacterial crude extract (CE) containing MC. The Neotropical erythrinid fish, Hoplias malabaricus, were exposed intraperitoneally to CE containing 100 μg MC-LR eq kg-1 for 30 days and, thereafter, the plasma, liver, and white muscle was sampled for analyses. Liver tissue lost cellular structure organization showing round hepatocytes, hyperemia, and biliary duct obstruction. At the ultrastructural level, the mitochondria and the endoplasmic reticulum exhibited disorganization. Direct and total bilirubin increased in plasma. In the liver, the activity of acid phosphatase (ACP) increased, and the aspartate aminotransferase (AST) decreased; AST increased in plasma. Alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were unchanged in the liver, muscle, and plasma. Glycogen stores and the energetic metabolites as glucose, lactate, and pyruvate decrease in the liver; pyruvate decreased in plasma and lactate decreased in muscle. Ammonia levels increased and protein concentration decreased in plasma. CE alters liver morphology by causing hepatocyte intracellular disorder, obstructive cholestasis, and dysfunction in the activity of key liver enzymes. The increasing energy demand implies glucose mobilization and metabolic adjustments maintaining protein preservation and lipid recruitment to supply the needs for detoxification allowing fish survival.

RevDate: 2022-10-19
CmpDate: 2022-09-08

Schavemaker PE, SA Muñoz-Gómez (2022)

The role of mitochondrial energetics in the origin and diversification of eukaryotes.

Nature ecology & evolution, 6(9):1307-1317.

The origin of eukaryotic cell size and complexity is often thought to have required an energy excess supplied by mitochondria. Recent observations show energy demands to scale continuously with cell volume, suggesting that eukaryotes do not have higher energetic capacity. However, respiratory membrane area scales superlinearly with the cell surface area. Furthermore, the consequences of the contrasting genomic architectures between prokaryotes and eukaryotes have not been precisely quantified. Here, we investigated (1) the factors that affect the volumes at which prokaryotes become surface area-constrained, (2) the amount of energy divested to DNA due to contrasting genomic architectures and (3) the costs and benefits of respiring symbionts. Our analyses suggest that prokaryotes are not surface area-constrained at volumes of 100‒103 µm3, the genomic architecture of extant eukaryotes is only slightly advantageous at genomes sizes of 106‒107 base pairs and a larger host cell may have derived a greater advantage (lower cost) from harbouring ATP-producing symbionts. This suggests that eukaryotes first evolved without the need for mitochondria since these ranges hypothetically encompass the last eukaryotic common ancestor and its relatives. Our analyses also show that larger and faster-dividing prokaryotes would have a shortage of respiratory membrane area and divest more energy into DNA. Thus, we argue that although mitochondria may not have been required by the first eukaryotes, eukaryote diversification was ultimately dependent on mitochondria.

RevDate: 2022-08-02

Yu J, Ran Z, Zhang J, et al (2022)

Genome-Wide Insights Into the Organelle Translocation of Photosynthetic NDH-1 Genes During Evolution.

Frontiers in microbiology, 13:956578.

Translocation of chloroplast-located genes to mitochondria or nucleus is considered to be a safety strategy that impedes mutation of photosynthetic genes and maintains their household function during evolution. The organelle translocation strategy is also developed in photosynthetic NDH-1 (pNDH-1) genes but its understanding is still far from complete. Here, we found that the mutation rate of the conserved pNDH-1 genes was gradually reduced but their selection pressure was maintained at a high level during evolution from cyanobacteria to angiosperm. By contrast, oxygenic photosynthesis-specific (OPS) pNDH-1 genes had an opposite trend, explaining the reason why they were transferred from the reactive oxygen species (ROS)-enriched chloroplast to the ROS-barren nucleus. Further, genome-wide sequence analysis supported the possibility that all conserved pNDH-1 genes lost in chloroplast genomes of Chlorophyceae and Pinaceae were transferred to the ROS-less mitochondrial genome as deduced from their truncated pNDH-1 gene fragments. Collectively, we propose that the organelle translocation strategy of pNDH-1 genes during evolution is necessary to maintain the function of the pNDH-1 complex as an important antioxidant mechanism for efficient photosynthesis.

RevDate: 2022-07-28

Pani P, NC Bal (2022)

Avian adjustments to cold and non-shivering thermogenesis: whats, wheres and hows.

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

Avian cold adaptation is hallmarked by innovative strategies of both heat conservation and thermogenesis. While minimizing heat loss can reduce the thermogenic demands of body temperature maintenance, it cannot eliminate the requirement for thermogenesis. Shivering and non-shivering thermogenesis (NST) are the two synergistic mechanisms contributing to endothermy. Birds are of particular interest in studies of NST as they lack brown adipose tissue (BAT), the major organ of NST in mammals. Critical analysis of the existing literature on avian strategies of cold adaptation suggests that skeletal muscle is the principal site of NST. Despite recent progress, isolating the mechanisms involved in avian muscle NST has been difficult as shivering and NST co-exist with its primary locomotory function. Herein, we re-evaluate various proposed molecular bases of avian skeletal muscle NST. Experimental evidence suggests that sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA) and ryanodine receptor 1 (RyR1) are key in avian muscle NST, through their mediation of futile Ca2+ cycling and thermogenesis. More recent studies have shown that SERCA regulation by sarcolipin (SLN) facilitates muscle NST in mammals; however, its role in birds is unclear. Ca2+ signalling in the muscle seems to be common to contraction, shivering and NST, but elucidating its roles will require more precise measurement of local Ca2+ levels inside avian myofibres. The endocrine control of avian muscle NST is still poorly defined. A better understanding of the mechanistic details of avian muscle NST will provide insights into the roles of these processes in regulatory thermogenesis, which could further inform our understanding of the evolution of endothermy among vertebrates.

RevDate: 2022-09-23
CmpDate: 2022-09-15

Atayik MC, U Çakatay (2022)

Melatonin-related signaling pathways and their regulatory effects in aging organisms.

Biogerontology, 23(5):529-539.

Melatonin is a tryptophan-derived ancestral molecule evolved in bacteria. According to the endosymbiotic theory, eukaryotic cells received mitochondria, plastids, and other organelles from bacteria by internalization. After the endosymbiosis, bacteria evolved into organelles and retained their ability of producing melatonin. Melatonin is a small, evolutionarily conserved indole with multiple receptor-mediated, receptor-dependent, and independent actions. Melatonin's initial function was likely a radical scavenger in bacteria that's why there was high intensity of free radicals on primitive atmosphere in the ancient times, and hormetic functions of melatonin, which are effecting through the level of gene expression via prooxidant and antioxidant redox pathways, are developed in throughout the eukaryotic evolution. In the earlier stages of life, endosymbiotic events between mitochondria and other downstream organelles continue with mutual benefits. However, this interaction gradually deteriorates as a result of the imperfection of both mitochondrial and extramitochondrial endosymbiotic crosstalk with the advancing age of eukaryotic organisms. Throughout the aging process melatonin levels tend to reduce and as a manifestation of this, many symptoms in organisms' homeostasis, such as deterioration in adjustment of cellular clocks, are commonly seen. In addition, due to deterioration in mitochondrial integrity and functions, immunity decreases, and lower levels of melatonin renders older individuals to be more susceptible to impaired redox modulation and age-related diseases. Our aim in this paper is to focus on the several redox modulation mechanisms in which melatonin signaling has a central role, to discuss melatonin's gerontological aspects and to provide new research ideas with researchers.

RevDate: 2022-07-31
CmpDate: 2022-07-28

Ghanem J, Passadori A, Severac F, et al (2022)

Effects of Rehabilitation on Long-COVID-19 Patient's Autonomy, Symptoms and Nutritional Observance.

Nutrients, 14(15):.

BACKGROUND: Despite significant improvements in COVID-19 therapy, many patients still present with persistent symptoms and quality-of-life alterations. The aim of this study was to simultaneously investigate the long-term evolution of autonomy, malnutrition and long-lasting symptoms in people infected with COVID-19 and hospitalized in the ICU.

METHOD: Patients' clinical characteristics; extent of their loss of autonomy based on "Autonomie Gérontologie Groupes Iso-Ressources" (AG-GIR) classification; nutritional status while following the French and Global Leadership Initiative on Malnutrition (GLIM) recommendations; and symptom evolutions before infection, during hospitalization and rehabilitation, and up to 6 months after returning home were determined in thirty-seven patients.

RESULTS: Prior to a COVID-19 infection, all patients were autonomous, but upon admission to the rehabilitation center (CRM), 39% of them became highly dependent. After discharge from the center and 6 months after returning home, only 6 and 3%, respectively, still required considerable assistance. Of these thirty-seven patients, 11% were moderately malnourished and 81% presented with severe malnutrition, with a significant correlation being observed between malnutrition and autonomy (p < 0.05). Except for fatigue, which persisted in 70% of the patients 6 months after discharge from rehabilitation, all other symptoms decreased significantly.

CONCLUSIONS: This study shows a striking decrease in autonomy associated with malnutrition after hospitalization for a COVID-19 infection and a clear beneficial effect from personalized rehabilitation. However, although almost all patients regained autonomy 6 months after returning home, they often still suffer from fatigue. Patient compliance with their nutritional recommendations deserves further improvement, preferably through personalized and persistent follow-up with the patient.

RevDate: 2022-08-04

Tao J, Li B, Cheng J, et al (2022)

Genomic Divergence Characterization and Quantitative Proteomics Exploration of Type 4 Porcine Astrovirus.

Viruses, 14(7):.

Porcine astrovirus (PAstV) has been identified as an important diarrheic pathogen with a broad global distribution. The PAstV is a potential pathogen to human beings and plays a role in public health. Until now, the divergence characteristics and pathogenesis of the PAstV are still not well known. In this study, the PAstV-4 strain PAstV/CH/2022/CM1 was isolated from the diarrheal feces of a piglet in Shanghai, which was identified to be a recombination of PAstV4/JPN (LC201612) and PAstV4/CHN (JX060808). A time tree based on the ORF2 protein of the astrovirus demonstrated that type 2-5 PAstV (PAstV-2 to 5) diverged from type 1 PAstV (PAstV-1) at a point from 1992 to 2000. To better understand the molecular basis of the virus, we sought to explore the host cell response to the PAstV/CH/2022/CM1 infection using proteomics. The results demonstrate that viral infection elicits global protein changes, and that the mitochondria seems to be a primary and an important target in viral infection. Importantly, there was crosstalk between autophagy and apoptosis, in which ATG7 might be the key mediator. In addition, the NOD-like receptor X1 (NLRX1) in the mitochondria was activated and participated in several important antiviral signaling pathways after the PAstV/CH/2022/CM1 infection, which was closely related to mitophagy. The NLRX1 may be a crucial protein for antagonizing a viral infection through autophagy, but this has yet to be validated. In conclusion, the data in this study provides more information for understanding the virus genomic characterization and the potential antiviral targets in a PAstV infection.

RevDate: 2022-07-31

Mendoza-Hoffmann F, Zarco-Zavala M, Ortega R, et al (2022)

Evolution of the Inhibitory and Non-Inhibitory ε, ζ, and IF1 Subunits of the F1FO-ATPase as Related to the Endosymbiotic Origin of Mitochondria.

Microorganisms, 10(7):.

The F1FO-ATP synthase nanomotor synthesizes >90% of the cellular ATP of almost all living beings by rotating in the "forward" direction, but it can also consume the same ATP pools by rotating in "reverse." To prevent futile F1FO-ATPase activity, several different inhibitory proteins or domains in bacteria (ε and ζ subunits), mitochondria (IF1), and chloroplasts (ε and γ disulfide) emerged to block the F1FO-ATPase activity selectively. In this study, we analyze how these F1FO-ATPase inhibitory proteins have evolved. The phylogeny of the α-proteobacterial ε showed that it diverged in its C-terminal side, thus losing both the inhibitory function and the ATP-binding/sensor motif that controls this inhibition. The losses of inhibitory function and the ATP-binding site correlate with an evolutionary divergence of non-inhibitory α-proteobacterial ε and mitochondrial δ subunits from inhibitory bacterial and chloroplastidic ε subunits. Here, we confirm the lack of inhibitory function of wild-type and C-terminal truncated ε subunits of P. denitrificans. Taken together, the data show that ζ evolved to replace ε as the primary inhibitor of the F1FO-ATPase of free-living α-proteobacteria. However, the ζ inhibitory function was also partially lost in some symbiotic α-proteobacteria and totally lost in some strictly parasitic α-proteobacteria such as the Rickettsiales order. Finally, we found that ζ and IF1 likely evolved independently via convergent evolution before and after the endosymbiotic origin mitochondria, respectively. This led us to propose the ε and ζ subunits as tracer genes of the pre-endosymbiont that evolved into the actual mitochondria.

RevDate: 2022-07-31

Shang Y, Wang X, Liu G, et al (2022)

Adaptability and Evolution of Gobiidae: A Genetic Exploration.

Animals : an open access journal from MDPI, 12(14):.

The Gobiidae family occupy one of the most diverse habitat ranges of all fishes. One key reason for their successful colonization of different habitats is their ability to adapt to different energy demands. This energy requirement is related to the ability of mitochondria in cells to generate energy via oxidative phosphorylation (OXPHOS). Here, we assembled three complete mitochondrial genomes of Rhinogobius shennongensis, Rhinogobius wuyanlingensis, and Chaenogobius annularis. These mitogenomes are circular and include 13 protein-coding genes (PCGs), two rRNAs, 22 tRNAs, and one non-coding control region (CR). We used comparative mitochondrial DNA (mtDNA) genome and selection pressure analyses to explore the structure and evolutionary rates of Gobiidae mitogenomics in different environments. The CmC model showed that the ω ratios of all mtDNA PCGs were <1, and that the evolutionary rate of adenosine triphosphate 8 (atp8) was faster in Gobiidae than in other mitochondrial DNA PCGs. We also found evidence of positive selection for several sites of NADH dehydrogenase (nd) 6 and atp8 genes. Thus, divergent mechanisms appear to underlie the evolution of mtDNA PCGs, which might explain the ability of Gobiidae to adapt to diverse environments. Our study provides new insights on the adaptive evolution of Gobiidae mtDNA genome and molecular mechanisms of OXPHOS.

RevDate: 2022-07-29
CmpDate: 2022-07-27

Ge H, Xu J, Hua M, et al (2022)

Genome-wide identification and analysis of ACP gene family in Sorghum bicolor (L.) Moench.

BMC genomics, 23(1):538.

BACKGROUND: Acyl carrier proteins (ACP) constitute a very conserved carrier protein family. Previous studies have found that ACP not only takes part in the fatty acid synthesis process of almost all organisms, but also participates in the regulation of plant growth, development, and metabolism, and makes plants adaptable to stresses. However, this gene family has not been systematically studied in sorghum.

RESULTS: Nine ACP family members were identified in the sorghum genome, which were located on chromosomes 1, 2, 5, 7, 8 and 9, respectively. Evolutionary analysis among different species divided the ACP family into four subfamilies, showing that the SbACPs were more closely related to maize. The prediction results of subcellular localization showed that SbACPs were mainly distributed in chloroplasts and mitochondria, while fluorescence localization showed that SbACPs were mainly localized in chloroplasts in tobacco leaf. The analysis of gene structure revealed a relatively simple genetic structure, that there were 1-3 introns in the sorghum ACP family, and the gene structure within the same subfamily had high similarity. The amplification method of SbACPs was mainly large fragment replication, and SbACPs were more closely related to ACPs in maize and rice. In addition, three-dimensional structure analysis showed that all ACP genes in sorghum contained four α helices, and the second helix structure was more conserved, implying a key role in function. Cis-acting element analysis indicated that the SbACPs might be involved in light response, plant growth and development regulation, biotic and abiotic stress response, plant hormone regulation, and other physiological processes. What's more, qRT-PCR analysis uncovered that some of SbACPs might be involved in the adaptive regulation of drought and salt stresses, indicating the close relationship between fatty acids and the resistance to abiotic stresses in sorghum.

CONCLUSIONS: In summary, these results showed a comprehensive overview of the SbACPs and provided a theoretical basis for further studies on the biological functions of SbACPs in sorghum growth, development and abiotic stress responses.

RevDate: 2022-10-17
CmpDate: 2022-09-19

Wu CS, SM Chaw (2022)

Evolution of mitochondrial RNA editing in extant gymnosperms.

The Plant journal : for cell and molecular biology, 111(6):1676-1687.

To unveil the evolution of mitochondrial RNA editing in gymnosperms, we characterized mitochondrial genomes (mitogenomes), plastid genomes, RNA editing sites, and pentatricopeptide repeat (PPR) proteins from 10 key taxa representing four of the five extant gymnosperm clades. The assembled mitogenomes vary in gene content due to massive gene losses in Gnetum and Conifer II clades. Mitochondrial gene expression levels also vary according to protein function, with the most highly expressed genes involved in the respiratory complex. We identified 9132 mitochondrial C-to-U editing sites, as well as 2846 P-class and 8530 PLS-class PPR proteins. Regains of editing sites were demonstrated in Conifer II rps3 transcripts whose corresponding mitogenomic sequences lack introns due to retroprocessing. Our analyses reveal that non-synonymous editing is efficient and results in more codons encoding hydrophobic amino acids. In contrast, synonymous editing, although performed with variable efficiency, can increase the number of U-ending codons that are preferentially utilized in gymnosperm mitochondria. The inferred loss-to-gain ratio of mitochondrial editing sites in gymnosperms is 2.1:1, of which losses of non-synonymous editing are mainly due to genomic C-to-T substitutions. However, such substitutions only explain a small fraction of synonymous editing site losses, indicating distinct evolutionary mechanisms. We show that gymnosperms have experienced multiple lineage-specific duplications in PLS-class PPR proteins. These duplications likely contribute to accumulated RNA editing sites, as a mechanistic correlation between RNA editing and PLS-class PPR proteins is statistically supported.

RevDate: 2022-09-09
CmpDate: 2022-08-12

Ebner JN, Wyss MK, Ritz D, et al (2022)

Effects of thermal acclimation on the proteome of the planarian Crenobia alpina from an alpine freshwater spring.

The Journal of experimental biology, 225(15):.

Species' acclimation capacity and their ability to maintain molecular homeostasis outside ideal temperature ranges will partly predict their success following climate change-induced thermal regime shifts. Theory predicts that ectothermic organisms from thermally stable environments have muted plasticity, and that these species may be particularly vulnerable to temperature increases. Whether such species retained or lost acclimation capacity remains largely unknown. We studied proteome changes in the planarian Crenobia alpina, a prominent member of cold-stable alpine habitats that is considered to be a cold-adapted stenotherm. We found that the species' critical thermal maximum (CTmax) is above its experienced habitat temperatures and that different populations exhibit differential CTmax acclimation capacity, whereby an alpine population showed reduced plasticity. In a separate experiment, we acclimated C. alpina individuals from the alpine population to 8, 11, 14 or 17°C over the course of 168 h and compared their comprehensively annotated proteomes. Network analyses of 3399 proteins and protein set enrichment showed that while the species' proteome is overall stable across these temperatures, protein sets functioning in oxidative stress response, mitochondria, protein synthesis and turnover are lower in abundance following warm acclimation. Proteins associated with an unfolded protein response, ciliogenesis, tissue damage repair, development and the innate immune system were higher in abundance following warm acclimation. Our findings suggest that this species has not suffered DNA decay (e.g. loss of heat-shock proteins) during evolution in a cold-stable environment and has retained plasticity in response to elevated temperatures, challenging the notion that stable environments necessarily result in muted plasticity.

RevDate: 2022-10-18
CmpDate: 2022-09-22

Visinoni F, D Delneri (2022)

Mitonuclear interplay in yeast: from speciation to phenotypic adaptation.

Current opinion in genetics & development, 76:101957.

Saccharomyces yeasts have evolved into an important model system to study mitonuclear incompatibilities, thanks to recent advances in the field of sequencing, yeast hybridisation and multigenerational breeding. Yeast hybrids contain two homologous proteomes but retain only one type of mitochondria allowing studies on the effect of mitochondria on phenotype and gene expression. Here, we discuss the recent developments in the growing field of yeast mitogenomics spanning from the impact that this organelle has in shaping yeast fitness and genome evolution to the dissection of molecular determinants of mitonuclear incompatibilities. Applying the state-of-the-art genetic tools to a broader range of natural yeast species from different environments will help progress the field and untap the mitochondrial potential in strain development.

RevDate: 2022-07-22

McCall CE, Zhu X, Zabalawi M, et al (2022)

Sepsis, pyruvate, and mitochondria energy supply chain shortage.

Journal of leukocyte biology [Epub ahead of print].

Balancing high energy-consuming danger resistance and low energy supply of disease tolerance is a universal survival principle that often fails during sepsis. Our research supports the concept that sepsis phosphorylates and deactivates mitochondrial pyruvate dehydrogenase complex control over the tricarboxylic cycle and the electron transport chain. StimulatIng mitochondrial energetics in septic mice and human sepsis cell models can be achieved by inhibiting pyruvate dehydrogenase kinases with the pyruvate structural analog dichloroacetate. Stimulating the pyruvate dehydrogenase complex by dichloroacetate reverses a disruption in the tricarboxylic cycle that induces itaconate, a key mediator of the disease tolerance pathway. Dichloroacetate treatment increases mitochondrial respiration and ATP synthesis, decreases oxidant stress, overcomes metabolic paralysis, regenerates tissue, organ, and innate and adaptive immune cells, and doubles the survival rate in a murine model of sepsis.

RevDate: 2022-08-10
CmpDate: 2022-07-25

Cadart C, R Heald (2022)

Scaling of biosynthesis and metabolism with cell size.

Molecular biology of the cell, 33(9):.

Cells adopt a size that is optimal for their function, and pushing them beyond this limit can cause cell aging and death by senescence or reduce proliferative potential. However, by increasing their genome copy number (ploidy), cells can increase their size dramatically and homeostatically maintain physiological properties such as biosynthesis rate. Recent studies investigating the relationship between cell size and rates of biosynthesis and metabolism under normal, polyploid, and pathological conditions are revealing new insights into how cells attain the best function or fitness for their size by tuning processes including transcription, translation, and mitochondrial respiration. A new frontier is to connect single-cell scaling relationships with tissue and whole-organism physiology, which promises to reveal molecular and evolutionary principles underlying the astonishing diversity of size observed across the tree of life.

RevDate: 2022-07-29

Brzęk P, Roussel D, M Konarzewski (2022)

Mice selected for a high basal metabolic rate evolved larger guts but not more efficient mitochondria.

Proceedings. Biological sciences, 289(1978):20220719.

Intra-specific variation in both the basal metabolic rate (BMR) and mitochondrial efficiency (the amount of ATP produced per unit of oxygen consumed) has profound evolutionary and ecological consequences. However, the functional mechanisms responsible for this variation are not fully understood. Mitochondrial efficiency is negatively correlated with BMR at the interspecific level but it is positively correlated with performance capacity at the intra-specific level. This discrepancy is surprising, as theories explaining the evolution of endothermy assume a positive correlation between BMR and performance capacity. Here, we quantified mitochondrial oxidative phosphorylation activity and efficiency in two lines of laboratory mice divergently selected for either high (H-BMR) or low (L-BMR) levels of BMR. H-BMR mice had larger livers and kidneys (organs that are important predictors of BMR). H-BMR mice also showed higher oxidative phosphorylation activity in liver mitochondria but this difference can be hypothesized to be a direct effect of selection only if the heritability of this trait is low. However, mitochondrial efficiency in all studied organs did not differ between the two lines. We conclude that the rapid evolution of BMR can reflect changes in organ size rather than mitochondrial properties, and does not need to be accompanied obligatorily by changes in mitochondrial efficiency.

RevDate: 2022-08-18
CmpDate: 2022-07-21

Carter CS, MA Kingsbury (2022)

Oxytocin and oxygen: the evolution of a solution to the 'stress of life'.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 377(1858):20210054.

Oxytocin (OT) and the OT receptor occupy essential roles in our current understanding of mammalian evolution, survival, sociality and reproduction. This narrative review examines the hypothesis that many functions attributed to OT can be traced back to conditions on early Earth, including challenges associated with managing life in the presence of oxygen and other basic elements, including sulfur. OT regulates oxidative stress and inflammation especially through effects on the mitochondria. A related nonapeptide, vasopressin, as well as molecules in the hypothalamic-pituitary-adrenal axis, including the corticotropin-releasing hormone family of molecules, have a broad set of functions that interact with OT. Interactions among these molecules have roles in the causes and consequence of social behaviour and the management of threat, fear and stress. Here, we discuss emerging evidence suggesting that unique properties of the OT system allowed vertebrates, and especially mammals, to manage over-reactivity to the 'side effects' of oxygen, including inflammation, oxidation and free radicals, while also supporting high levels of sociality and a perception of safety. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

RevDate: 2022-10-11
CmpDate: 2022-10-06

Rottenberg H (2022)

The accelerated evolution of human cytochrome c oxidase - Selection for reduced rate and proton pumping efficiency?.

Biochimica et biophysica acta. Bioenergetics, 1863(8):148595.

The cytochrome c oxidase complex, complex VI (CIV), catalyzes the terminal step of the mitochondrial electron transport chain where the reduction of oxygen to water by cytochrome c is coupled to the generation of a protonmotive force that drive the synthesis of ATP. CIV evolution was greatly accelerated in humans and other anthropoid primates and appears to be driven by adaptive selection. However, it is not known if there are significant functional differences between the anthropoid primates CIV, and other mammals. Comparison of the high-resolution structures of bovine CIV, mouse CIV and human CIV shows structural differences that are associated with anthropoid-specific substitutions. Here I examine the possible effects of these substitutions in four CIV peptides that are known to affect proton pumping: the mtDNA-coded subunits I, II and III, and the nuclear-encoded subunit VIa2. I conclude that many of the anthropoid-specific substitutions could be expected to modulate the rate and/or the efficiency of proton pumping. These results are compatible with the previously proposed hypothesis that the accelerated evolution of CIV in anthropoid primates is driven by selection pressure to lower the mitochondrial protonmotive force and thus decrease the rate of superoxide generation by mitochondria.

RevDate: 2022-10-11
CmpDate: 2022-09-28

Biró B, Gál Z, Schiavo G, et al (2022)

Nuclear mitochondrial DNA sequences in the rabbit genome.

Mitochondrion, 66:1-6.

Numtogenesis is observable in the mammalian genomes resulting in the integration of mitochondrial segments into the nuclear genomes (numts). To identify numts in rabbit, we aligned mitochondrial and nuclear genomes. Alignment significance threshold was calculated and individual characteristics of numts were analysed. We found 153 numts in the nuclear genome. The GC content of numts were significantly lower than the GC content of their genomic flanking regions or the genome itself. The frequency of three mammalian-wide interspersed repeats were increased in the proximity of numts. The decreased GC content around numts strengthen the theory which supposes a link between DNA structural instability and numt integration.

RevDate: 2022-08-29

Shen LL, Waheed A, Wang YP, et al (2022)

Mitochondrial Genome Contributes to the Thermal Adaptation of the Oomycete Phytophthora infestans.

Frontiers in microbiology, 13:928464.

As a vital element of climate change, elevated temperatures resulting from global warming present new challenges to natural and agricultural sustainability, such as ecological disease management. Mitochondria regulate the energy production of cells in responding to environmental fluctuation, but studying their contribution to the thermal adaptation of species is limited. This knowledge is needed to predict future disease epidemiology for ecology conservation and food security. Spatial distributions of the mitochondrial genome (mtDNA) in 405 Phytophthora infestans isolates originating from 15 locations were characterized. The contribution of MtDNA to thermal adaptation was evaluated by comparative analysis of mtDNA frequency and intrinsic growth rate, relative population differentiation in nuclear and mtDNA, and associations of mtDNA distribution with local geography climate conditions. Significant variation in frequency, intrinsic growth rate, and spatial distribution was detected in mtDNA. Population differentiation in mtDNA was significantly higher than that in the nuclear genome, and spatial distribution of mtDNA was strongly associated with local climatic conditions and geographic parameters, particularly air temperature, suggesting natural selection caused by a local temperature is the main driver of the adaptation. Dominant mtDNA grew faster than the less frequent mtDNA. Our results provide useful insights into the evolution of pathogens under global warming. Given its important role in biological functions and adaptation to local air temperature, mtDNA intervention has become an increasing necessity for future disease management. To secure ecological integrity and food production under global warming, a synergistic study on the interactive effect of changing temperature on various components of biological and ecological functions of mitochondria in an evolutionary frame is urgently needed.

RevDate: 2022-10-20

Bononi G, Masoni S, Di Bussolo V, et al (2022)

Historical perspective of tumor glycolysis: A century with Otto Warburg.

Seminars in cancer biology, 86(Pt 2):325-333 pii:S1044-579X(22)00162-6 [Epub ahead of print].

Tumors have long been known to rewire their metabolism to endorse their proliferation, growth, survival, and invasiveness. One of the common characteristics of these alterations is the enhanced glucose uptake and its subsequent transformation into lactic acid by means of glycolysis, regardless the availability of oxygen or the mitochondria effectiveness. This phenomenon is called the "Warburg effect", which has turned into a century of age now, since its first disclosure by German physiologist Otto Heinrich Warburg. Since then, this peculiar metabolic switch in tumors has been addressed by extensive studies covering several areas of research. In this historical perspective, we aim at illustrating the evolution of these studies over time and their implication in various fields of science.

RevDate: 2022-07-08
CmpDate: 2022-07-08

Gumińska N, R Milanowski (2022)

Types of circular DNA in Eukarya.

Postepy biochemii, 68(2):129-141.

In eukaryotic cells, DNA occurs mainly in a linear chromosomes. In addition, it can also take the form of circular molecules. Mitochondrial and chloroplast genomes are the most thoroughly studied circular DNAs. However, the repertoire of circular DNA in Eukarya is much broader. It also includes extrachromosomal circular DNA (eccDNA): circular forms of rDNA, telomeric circles, small polydisperse DNA, microDNA, and other types of eccDNA of nuclear origin. The occurrence of eccDNA has been confirmed in all organisms tested so far. Previous studies have shown that some eccDNAs are present at every stage of the cell cycle, while others appear and/or accumulate under specific circumstances. It has been proven that eccDNA accumulation accompanies severe genome destabilization caused by malignancies or stress conditions. Despite growing interest in eccDNA, they remain a poorly understood component of eukaryotic genomes. Still little is known about the mechanisms of their formation, evolution and biological functions.

RevDate: 2022-08-16
CmpDate: 2022-08-09

Savu DI, N Moisoi (2022)

Mitochondria - Nucleus communication in neurodegenerative disease. Who talks first, who talks louder?.

Biochimica et biophysica acta. Bioenergetics, 1863(7):148588.

Mitochondria - nuclear coadaptation has been central to eukaryotic evolution. The dynamic dialogue between the two compartments within the context of multiorganellar interactions is critical for maintaining cellular homeostasis and directing the balance survival-death in case of cellular stress. The conceptualisation of mitochondria - nucleus communication has so far been focused on the communication from the mitochondria under stress to the nucleus and the consequent signalling responses, as well as from the nucleus to mitochondria in the context of DNA damage and repair. During ageing processes this dialogue may be better viewed as an integrated bidirectional 'talk' with feedback loops that expand beyond these two organelles depending on physiological cues. Here we explore the current views on mitochondria - nucleus dialogue and its role in maintaining cellular health with a focus on brain cells and neurodegenerative disease. Thus, we detail the transcriptional responses initiated by mitochondrial dysfunction in order to protect itself and the general cellular homeostasis. Additionally, we are reviewing the knowledge of the stress pathways initiated by DNA damage which affect mitochondria homeostasis and we add the information provided by the study of combined mitochondrial and genotoxic damage. Finally, we reflect on how each organelle may take the lead in this dialogue in an ageing context where both compartments undergo accumulation of stress and damage and where, perhaps, even the communications' mechanisms may suffer interruptions.

RevDate: 2022-09-23

Anonymous (2022)

Abstracts of Presentations at the Association of Clinical Scientists 143rd Meeting Louisville, KY May 11-14,2022.

Annals of clinical and laboratory science, 52(3):511-525.

RevDate: 2022-09-08

Jardim-Messeder D, Zamocky M, Sachetto-Martins G, et al (2022)

Chloroplastic ascorbate peroxidases targeted to stroma or thylakoid membrane: The chicken or egg dilemma.

FEBS letters [Epub ahead of print].

Ascorbate peroxidases (APXs) are heme peroxidases that remove hydrogen peroxide in different subcellular compartments with concomitant ascorbate cycling. Here, we analysed and discussed phylogenetic and molecular features of the APX family. Ancient APX originated as a soluble stromal enzyme, and early during plant evolution, acquired both chloroplast-targeting and mitochondrion-targeting sequences and an alternative splicing mechanism whereby it could be expressed as a soluble or thylakoid membrane-bound enzyme. Later, independent duplication and neofunctionalization events in some angiosperm groups resulted in individual genes encoding stromal, thylakoidal and mitochondrial isoforms. These data reaffirm the complexity of plant antioxidant defenses that allow diverse plant species to acquire new means to adapt to changing environmental conditions.

RevDate: 2022-08-04

Mondal S, Kinatukara P, Singh S, et al (2022)

DIP2 is a unique regulator of diacylglycerol lipid homeostasis in eukaryotes.

eLife, 11:.

Chain-length-specific subsets of diacylglycerol (DAG) lipids are proposed to regulate differential physiological responses ranging from signal transduction to modulation of the membrane properties. However, the mechanism or molecular players regulating the subsets of DAG species remain unknown. Here, we uncover the role of a conserved eukaryotic protein family, DISCO-interacting protein 2 (DIP2) as a homeostatic regulator of a chemically distinct subset of DAGs using yeast, fly, and mouse models. Genetic and chemical screens along with lipidomics analysis in yeast reveal that DIP2 prevents the toxic accumulation of specific DAGs in the logarithmic growth phase, which otherwise leads to endoplasmic reticulum stress. We also show that the fatty acyl-AMP ligase-like domains of DIP2 are essential for the redirection of the flux of DAG subspecies to storage lipid, triacylglycerols. DIP2 is associated with vacuoles through mitochondria-vacuole contact sites and such modulation of selective DAG abundance by DIP2 is found to be crucial for optimal vacuole membrane fusion and consequently osmoadaptation in yeast. Thus, the study illuminates an unprecedented DAG metabolism route and provides new insights on how cell fine-tunes DAG subspecies for cellular homeostasis and environmental adaptation.

RevDate: 2022-10-11
CmpDate: 2022-10-11

Kurt F, Kurt B, Filiz E, et al (2022)

Mitochondrial iron transporter (MIT) gene in potato (Solanum tuberosum): comparative bioinformatics, physiological and expression analyses in response to drought and salinity.

Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine, 35(5):875-887.

Mitochondrial iron transporter (MIT) genes are essential for mitochondrial acquisition/import of iron and vital to proper functioning of mitochondria. Unlike other organisms, research on the MITs in plants is limited. The present study provides comparative bioinformatics assays for the potato MIT gene (StMIT) as well as gene expression analyses. The phylogenetic analyses revealed monocots-dicot divergence in MIT proteins and it was also found clade specific motif diversity. In addition, docking analyses indicated that Asp172 and Gly100 residues to be identified as the closest residues binding to ferrous iron. The percentage of structure overlap of the StMIT 3D protein model with Arabidopsis, maize and rice MIT proteins was found between 80.18% and 85.71%. The transcript analyses exhibited that the expression of StMIT was triggered under drought and salinity stresses. The findings of the present study would provide valuable leads for further studies targeting specifically the MIT gene and generally the plant iron metabolism.

RevDate: 2022-10-01
CmpDate: 2022-09-30

Anderson L, Camus MF, Monteith KM, et al (2022)

Variation in mitochondrial DNA affects locomotor activity and sleep in Drosophila melanogaster.

Heredity, 129(4):225-232.

Mitochondria are organelles that produce cellular energy in the form of ATP through oxidative phosphorylation, and this primary function is conserved among many taxa. Locomotion is a trait that is highly reliant on metabolic function and expected to be greatly affected by disruptions to mitochondrial performance. To this end, we aimed to examine how activity and sleep vary between Drosophila melanogaster strains with different geographic origins, how these patterns are affected by mitochondrial DNA (mtDNA) variation, and how breaking up co-evolved mito-nuclear gene combinations affect the studied activity traits. Our results demonstrate that Drosophila strains from different locations differ in sleep and activity, and that females are generally more active than males. By comparing activity and sleep of mtDNA variants introgressed onto a common nuclear background in cytoplasmic hybrid (cybrid) strains, we were able to quantify the among-line variance attributable to mitochondrial DNA, and we establish that mtDNA variation affects both activity and sleep, in a sex-specific manner. Altogether our study highlights the important role that mitochondrial genome variation plays on organismal physiology and behaviour.

RevDate: 2022-09-01
CmpDate: 2022-06-30

Jenkins HL, Graham R, Porter JS, et al (2022)

Unprecedented frequency of mitochondrial introns in colonial bilaterians.

Scientific reports, 12(1):10889.

Animal mitogenomes are typically devoid of introns. Here, we report the largest number of mitochondrial introns ever recorded from bilaterian animals. Mitochondrial introns were identified for the first time from the phylum Bryozoa. They were found in four species from three families (Order Cheilostomatida). A total of eight introns were found in the complete mitogenome of Exechonella vieirai, and five, 17 and 18 introns were found in the partial mitogenomes of Parantropora penelope, Discoporella cookae and Cupuladria biporosa, respectively. Intron-encoded protein domains reverse transcriptase and intron maturase (RVT-IM) were identified in all species. Introns in E. vieirai and P. penelope had conserved Group II intron ribozyme domains V and VI. Conserved domains were lacking from introns in D. cookae and C. biporosa, preventing their further categorization. Putative origins of metazoan introns were explored in a phylogenetic context, using an up-to-date alignment of mitochondrial RVT-IM domains. Results confirmed previous findings of multiple origins of annelid, placozoan and sponge RVT-IM domains and provided evidence for common intron donor sources across metazoan phyla. Our results corroborate growing evidence that some metazoans with regenerative abilities (i.e. placozoans, sponges, annelids and bryozoans) are susceptible to intron integration, most likely via horizontal gene transfer.

RevDate: 2022-09-20
CmpDate: 2022-07-20

Garrido C, Wollman FA, I Lafontaine (2022)

The Evolutionary History of Peptidases Involved in the Processing of Organelle-Targeting Peptides.

Genome biology and evolution, 14(7):.

Most of the proteins present in mitochondria and chloroplasts, the organelles acquired via endosymbiotic events, are encoded in the nucleus and translated into the cytosol. Most of such nuclear-encoded proteins are specifically recognized via an N-terminal-encoded targeting peptide (TP) and imported into the organelles via a translocon machinery. Once imported, the TP is degraded by a succession of cleavage steps ensured by dedicated peptidases. Here, we retrace the evolution of the families of the mitochondrial processing peptidase (MPP), stromal processing peptidase (SPP), presequence protease (PreP), and organellar oligo-peptidase (OOP) that play a central role in TP processing and degradation across the tree of life. Their bacterial distributions are widespread but patchy, revealing unsurprisingly complex history of lateral transfers among bacteria. We provide evidence for the eukaryotic acquisition of MPP, OOP, and PreP by lateral gene transfers from bacteria at the time of the mitochondrial endosymbiosis. We show that the acquisition of SPP and of a second copy of OOP and PreP at the time of the chloroplast endosymbiosis was followed by a differential loss of one PreP paralog in photosynthetic eukaryotes. We identified some contrasting sequence conservations between bacterial and eukaryotic homologs that could reflect differences in the functional context of their peptidase activity. The close vicinity of the eukaryotic peptidases MPP and OOP to those of several bacterial pathogens, showing antimicrobial resistance, supports a scenario where such bacteria were instrumental in the establishment of the proteolytic pathway for TP degradation in organelles. The evidence for their role in the acquisition of PreP is weaker, and none is observed for SPP, although it cannot be excluded by the present study.

RevDate: 2022-07-16
CmpDate: 2022-06-27

Ždralević M, S Giannattasio (2022)

Mitochondrial Research: Yeast and Human Cells as Models.

International journal of molecular sciences, 23(12):.

The evolution of complex eukaryotes would have been impossible without mitochondria, key cell organelles responsible for the oxidative metabolism of sugars and the bulk of ATP production [...].

RevDate: 2022-09-24
CmpDate: 2022-06-27

Solana JC, Chicharro C, García E, et al (2022)

Assembly of a Large Collection of Maxicircle Sequences and Their Usefulness for Leishmania Taxonomy and Strain Typing.

Genes, 13(6):.

Parasites of medical importance, such as Leishmania and Trypanosoma, are characterized by the presence of thousands of circular DNA molecules forming a structure known as kinetoplast, within the mitochondria. The maxicircles, which are equivalent to the mitochondrial genome in other eukaryotes, have been proposed as a promising phylogenetic marker. Using whole-DNA sequencing data, it is also possible to assemble maxicircle sequences as shown here and in previous works. In this study, based on data available in public databases and using a bioinformatics workflow previously reported by our group, we assembled the complete coding region of the maxicircles for 26 prototypical strains of trypanosomatid species. Phylogenetic analysis based on this dataset resulted in a robust tree showing an accurate taxonomy of kinetoplastids, which was also able to discern between closely related Leishmania species that are usually difficult to discriminate by classical methodologies. In addition, we provide a dataset of the maxicircle sequences of 60 Leishmania infantum field isolates from America, Western Europe, North Africa, and Eastern Europe. In agreement with previous studies, our data indicate that L. infantum parasites from Brazil are highly homogeneous and closely related to European strains, which were transferred there during the discovery of America. However, this study showed the existence of different L. infantum populations/clades within the Mediterranean region. A maxicircle signature for each clade has been established. Interestingly, two L. infantum clades were found coexisting in the same region of Spain, one similar to the American strains, represented by the Spanish JPCM5 reference strain, and the other, named "non-JPC like", may be related to an important leishmaniasis outbreak that occurred in Madrid a few years ago. In conclusion, the maxicircle sequence emerges as a robust molecular marker for phylogenetic analysis and species typing within the kinetoplastids, which also has the potential to discriminate intraspecific variability.

RevDate: 2022-09-24
CmpDate: 2022-06-27

Hawkins MTR, Bailey CA, Brown AM, et al (2022)

Nuclear and Mitochondrial Phylogenomics of the Sifakas Reveal Cryptic Variation in the Diademed Sifaka.

Genes, 13(6):.

The most comprehensive phylogenomic reconstruction to date was generated on all nominal taxa within the lemur genus Propithecus. Over 200 wild-caught individuals were included in this study to evaluate the intra and interspecific relationships across this genus. Ultraconserved Elements (UCEs) resulted in well-supported phylogenomic trees. Complete mitochondrial genomes (CMGs) largely agreed with the UCEs, except where a mitochondrial introgression was detected between one clade of the diademed sifaka (Propithecus diadema) and the Milne-Edwards sifaka (P. edwardsi). Additionally, the crowned (P. coronatus) and Von der Decken's (P. deckeni) sifakas belonged to a single admixed lineage from UCEs. Further sampling across these two species is warranted to determine if our sampling represents a hybrid zone. P. diadema recovered two well-supported clades, which were dated and estimated as being ancient as the split between the Perrier's (P. perrierii) and silky (P. candidus) sifakas. The reconstructed demographic history of the two clades also varied over time. We then modeled the modern ecological niches of the two cryptic P. diadema clades and found that they were significantly diverged (p < 0.01). These ecological differences result in a very limited zone of geographic overlap for the P. diadema clades (<60 km2). Niche models also revealed that the Onive River acts as a potential barrier to dispersal between P. diadema and P. edwardsi. Further taxonomic work is required on P. diadema to determine if its taxonomic status should be revised. This first genomic evaluation of the genus resolved the relationships between the taxa and the recovered cryptic diversity within one species.

RevDate: 2022-09-26
CmpDate: 2022-06-27

Orlova VF, Solovyeva EN, Dunayev EA, et al (2022)

Integrative Taxonomy within Eremias multiocellata Complex (Sauria, Lacertidae) from the Western Part of Range: Evidence from Historical DNA.

Genes, 13(6):.

The Kokshaal racerunner, Eremias kokshaaliensis Eremchenko et Panfilov, 1999, together with other central Asian racerunner species, is included in the Eremias multiocellata complex. In the present work, for the first time, the results of the analysis of historical mitochondrial DNA (barcode) are presented and the taxonomic status and preliminary phylogenetic relationships within the complex are specified. We present, for the first time, the results of the molecular analysis using historical DNA recovered from specimens of several species of this complex (paratypes of the Kokshaal racerunner and historical collections of the Kashgar racerunner E. buechneri from Kashgaria) using DNA barcoding.

RevDate: 2022-07-16

Martínez-González JJ, Guevara-Flores A, IP Del Arenal Mena (2022)

Evolutionary Adaptations of Parasitic Flatworms to Different Oxygen Tensions.

Antioxidants (Basel, Switzerland), 11(6):.

During the evolution of the Earth, the increase in the atmospheric concentration of oxygen gave rise to the development of organisms with aerobic metabolism, which utilized this molecule as the ultimate electron acceptor, whereas other organisms maintained an anaerobic metabolism. Platyhelminthes exhibit both aerobic and anaerobic metabolism depending on the availability of oxygen in their environment and/or due to differential oxygen tensions during certain stages of their life cycle. As these organisms do not have a circulatory system, gas exchange occurs by the passive diffusion through their body wall. Consequently, the flatworms developed several adaptations related to the oxygen gradient that is established between the aerobic tegument and the cellular parenchyma that is mostly anaerobic. Because of the aerobic metabolism, hydrogen peroxide (H2O2) is produced in abundance. Catalase usually scavenges H2O2 in mammals; however, this enzyme is absent in parasitic platyhelminths. Thus, the architecture of the antioxidant systems is different, depending primarily on the superoxide dismutase, glutathione peroxidase, and peroxiredoxin enzymes represented mainly in the tegument. Here, we discuss the adaptations that parasitic flatworms have developed to be able to transit from the different metabolic conditions to those they are exposed to during their life cycle.

RevDate: 2022-08-07

P K, Chakraborty B, Rani V, et al (2022)

Rationally designed far-red emitting styryl chromones and a magnetic nanoconjugate for strip-based 'on-site' detection of metabolic markers.

Journal of materials chemistry. B, 10(26):5071-5085.

The global burden of liver damage and renal failure necessitates technology-aided evolution towards point-of-care (POC) testing of metabolic markers. Hence in the prevalence of current health conditions, achieving on-site detection and quantifying serum albumin (SA) can contribute significantly to halting the increased mortality and morbidity rate. Herein, we have rationally designed and synthesized far-red emitting, solvatofluorochromic styryl chromone (SC) derivatives SC1 and SC2, and SC2-conjugated fluorescent magnetic nanoparticles (SCNPs) for sensing SA with a fluorogenic response via interacting at an atypical drug binding site. In solution, the highly sensitive and selective fluorogenic response was evaluated by the prominent amplification and blue-shift in the emission maxima of the probes from deep red to dark yellow through an intermediate orange emission. The transformation of the fluorogen into a fluorophore was manifested through spectroscopic measurements. The stabilization of the probes at protein pockets was ascribed to the non-covalent interactions, such as H-bonding, cation-π, and hydrophobic interactions, as unveiled by docking studies. The practical applications revealed the novelty of SC derivatives through (a) the capability to detect SA isolated from real blood samples via a turn-on fluorescence response; (b) the design of a simple, cheap, and portable test-strip using a glass-slide loaded with solid-state emissive SC2, which provided differential emission color of the SC2-HSA complex in solution and the solid-state with increasing concentration of HSA. Moreover, a smartphone-based color analysis application was employed to obtain the ratio of green and red (G/R) channels, which was utilized for quantitative detection of HSA; (c) the biocompatibility of the SC1 was ascertained through confocal laser scanning microscopic imaging (CLSM). Detailed investigation showed that SC1 could entirely localize in the mitochondria and evolve as a promising biomarker for distinguishing cancer cells from normal cells. Additionally, the validation of uncommon binding of SC1 and SC2 between domains I and III was determined using competition experiments with a known site-specific binder and molecular docking studies. This unique property of the probes can be further exploited to understand the cellular intake of HSA-drug complexes in the multifaceted biological system. These results find the utility of SC derivatives as small molecule-based chemosensors for at-home SA detection and as a biomarker for cancer.

RevDate: 2022-07-16

Della Rocca G, Papini A, Posarelli I, et al (2022)

Ultrastructure of Terpene and Polyphenol Synthesis in the Bark of Cupressus sempervirens After Seiridium cardinale Infection.

Frontiers in microbiology, 13:886331.

Cypress Canker Disease (CCD) pandemic caused by Seiridium cardinale is the major constraint of many Cupressaceae worldwide. One of the main symptoms of the disease is the flow of resin from the cankered barks. While inducible phloem axial resin duct-like structures (PARDs) have recently been characterized from an anatomical point of view, their actual resin production is still being debated and has never been demonstrated. Although the involvement of polyphenolic parenchyma cells (PP cells) in the bark of Cupressus sempervirens after S. cardinale infection was revealed in one of our previous studies using light microscopy, their evolution from the phloem parenchyma cells is yet to be clarified. This study investigated functional and ultrastructural aspects of both PARD-like structures and PP cells by means of more in-depth light (LM) and fluorescence microscopy (FM) combined with histochemical staining (using Sudan red, Fluorol Yellow, NADI Aniline blue black, and Toluidine blue staining), in addition to Transmission Electron Microscope (TEM). Two-year-old stem sections of a C. sempervirens canker-resistant clone (var. "Bolgheri"), artificially inoculated with S. cardinale, were sampled 5, 7, 14, 21, and 45 days after inoculation, for time-course observations. FM observation using Fluorol yellow dye clearly showed the presence of lipid material in PARD-like structures lining cells of the cavity and during their secretion into the duct space/cavity. The same tissues were also positive for NADI staining, revealing the presence of terpenoids. The cytoplasm of the ducts' lining cells was also positive for Sudan red. TEM observation highlighted the involvement of plastids and endoplasmic reticulum in the production of terpenoids and the consequent secretion of terpenoids directly through the plasma membrane, without exhibiting vesicle formation. The presence of a high number of mitochondria around the area of terpenoid production suggests that this process is active and consumes ATP. The LM observations showed that PP cells originated from the phloem parenchyma cells (and possibly albuminous cells) through the accumulation of phenolic substances in the vacuole. Here, plastids were again involved in their production. Thus, the findings of this work suggest that the PARD-like structures can actually be considered PARDs or even bark traumatic resin ducts (BTRD).

RevDate: 2022-07-25
CmpDate: 2022-06-17

Wu B, Hao W, MP Cox (2022)

Reconstruction of gene innovation associated with major evolutionary transitions in the kingdom Fungi.

BMC biology, 20(1):144.

BACKGROUND: Fungi exhibit astonishing diversity with multiple major phenotypic transitions over the kingdom's evolutionary history. As part of this process, fungi developed hyphae, adapted to land environments (terrestrialization), and innovated their sexual structures. These changes also helped fungi establish ecological relationships with other organisms (animals and plants), but the genomic basis of these changes remains largely unknown.

RESULTS: By systematically analyzing 304 genomes from all major fungal groups, together with a broad range of eukaryotic outgroups, we have identified 188 novel orthogroups associated with major changes during the evolution of fungi. Functional annotations suggest that many of these orthogroups were involved in the formation of key trait innovations in extant fungi and are functionally connected. These innovations include components for cell wall formation, functioning of the spindle pole body, polarisome formation, hyphal growth, and mating group signaling. Innovation of mitochondria-localized proteins occurred widely during fungal transitions, indicating their previously unrecognized importance. We also find that prokaryote-derived horizontal gene transfer provided a small source of evolutionary novelty with such genes involved in key metabolic pathways.

CONCLUSIONS: The overall picture is one of a relatively small number of novel genes appearing at major evolutionary transitions in the phylogeny of fungi, with most arising de novo and horizontal gene transfer providing only a small additional source of evolutionary novelty. Our findings contribute to an increasingly detailed portrait of the gene families that define fungal phyla and underpin core features of extant fungi.

RevDate: 2022-08-19
CmpDate: 2022-08-19

Zheng J, Zhao L, Zhao X, et al (2022)

High Genetic Connectivity Inferred from Whole-Genome Resequencing Provides Insight into the Phylogeographic Pattern of Larimichthys polyactis.

Marine biotechnology (New York, N.Y.), 24(4):671-680.

Compared with terrestrial biota, marine fishes usually present lower genetic differentiation among different geographical populations because of high-level gene flow and lack of physical barriers. Understanding the genetic structure of marine fishes is essential for dividing management unit and making reasonable protection measures. The small yellow croaker (Larimichthys polyactis) belongs to the family Sciaenidae, which is an economic fish and widely distributed in the Western Pacific. To delineate genetic diversity and phylogeographic pattern, whole-genome resequencing was used to evaluate genetic connectivity, genetic diversity, and spatial pattern of L. polyactis for the first time. We obtained 6,645,711 high-quality single nucleotide polymorphisms (SNPs) markers from 40 L. polyactis individuals. The phylogenetic analysis, STRUCTURE, principal component analysis, and Fst results all indicated that no genetic structure consistent with the distribution pattern was found. This result revealed high genetic connectivity of L. polyactis in different sampling sites. High genetic diversity was also detected, indicating that there was sufficient evolutionary potential to maintain its effective population size. Besides, a similar result of high genetic connectivity and genetic diversity was also detected by mitochondria DNA marker. Our study demonstrated the persistence of high levels of genetic connectivity and a lack of population structure across L. polyactis in different sea areas. This study aimed to analyze the division of population structure and the reason for the decline and not exhaustion of L. polyactis resource on a genetic level.

RevDate: 2022-09-07
CmpDate: 2022-08-04

Brischigliaro M, Cabrera-Orefice A, Sturlese M, et al (2022)

CG7630 is the Drosophila melanogaster homolog of the cytochrome c oxidase subunit COX7B.

EMBO reports, 23(8):e54825.

The mitochondrial respiratory chain (MRC) is composed of four multiheteromeric enzyme complexes. According to the endosymbiotic origin of mitochondria, eukaryotic MRC derives from ancestral proteobacterial respiratory structures consisting of a minimal set of complexes formed by a few subunits associated with redox prosthetic groups. These enzymes, which are the "core" redox centers of respiration, acquired additional subunits, and increased their complexity throughout evolution. Cytochrome c oxidase (COX), the terminal component of MRC, has a highly interspecific heterogeneous composition. Mammalian COX consists of 14 different polypeptides, of which COX7B is considered the evolutionarily youngest subunit. We applied proteomic, biochemical, and genetic approaches to investigate the COX composition in the invertebrate model Drosophila melanogaster. We identified and characterized a novel subunit which is widely different in amino acid sequence, but similar in secondary and tertiary structures to COX7B, and provided evidence that this object is in fact replacing the latter subunit in virtually all protostome invertebrates. These results demonstrate that although individual structures may differ the composition of COX is functionally conserved between vertebrate and invertebrate species.

RevDate: 2022-08-11
CmpDate: 2022-06-15

Paredes GF, Viehboeck T, Markert S, et al (2022)

Differential regulation of degradation and immune pathways underlies adaptation of the ectosymbiotic nematode Laxus oneistus to oxic-anoxic interfaces.

Scientific reports, 12(1):9725.

Eukaryotes may experience oxygen deprivation under both physiological and pathological conditions. Because oxygen shortage leads to a reduction in cellular energy production, all eukaryotes studied so far conserve energy by suppressing their metabolism. However, the molecular physiology of animals that naturally and repeatedly experience anoxia is underexplored. One such animal is the marine nematode Laxus oneistus. It thrives, invariably coated by its sulfur-oxidizing symbiont Candidatus Thiosymbion oneisti, in anoxic sulfidic or hypoxic sand. Here, transcriptomics and proteomics showed that, whether in anoxia or not, L. oneistus mostly expressed genes involved in ubiquitination, energy generation, oxidative stress response, immune response, development, and translation. Importantly, ubiquitination genes were also highly expressed when the nematode was subjected to anoxic sulfidic conditions, together with genes involved in autophagy, detoxification and ribosome biogenesis. We hypothesize that these degradation pathways were induced to recycle damaged cellular components (mitochondria) and misfolded proteins into nutrients. Remarkably, when L. oneistus was subjected to anoxic sulfidic conditions, lectin and mucin genes were also upregulated, potentially to promote the attachment of its thiotrophic symbiont. Furthermore, the nematode appeared to survive oxygen deprivation by using an alternative electron carrier (rhodoquinone) and acceptor (fumarate), to rewire the electron transfer chain. On the other hand, under hypoxia, genes involved in costly processes (e.g., amino acid biosynthesis, development, feeding, mating) were upregulated, together with the worm's Toll-like innate immunity pathway and several immune effectors (e.g., bactericidal/permeability-increasing proteins, fungicides). In conclusion, we hypothesize that, in anoxic sulfidic sand, L. oneistus upregulates degradation processes, rewires the oxidative phosphorylation and reinforces its coat of bacterial sulfur-oxidizers. In upper sand layers, instead, it appears to produce broad-range antimicrobials and to exploit oxygen for biosynthesis and development.

RevDate: 2022-07-16
CmpDate: 2022-06-30

Jiang X, Coroian D, Barahona E, et al (2022)

Functional Nitrogenase Cofactor Maturase NifB in Mitochondria and Chloroplasts of Nicotiana benthamiana.

mBio, 13(3):e0026822.

Engineering plants to synthesize nitrogenase and assimilate atmospheric N2 will reduce crop dependency on industrial N fertilizers. This technology can be achieved by expressing prokaryotic nitrogen fixation gene products for the assembly of a functional nitrogenase in plants. NifB is a critical nitrogenase component since it catalyzes the first committed step in the biosynthesis of all types of nitrogenase active-site cofactors. Here, we used a library of 30 distinct nifB sequences originating from different phyla and ecological niches to restore diazotrophic growth of an Azotobacter vinelandii nifB mutant. Twenty of these variants rescued the nifB mutant phenotype despite their phylogenetic distance to A. vinelandii. Because multiple protein interactions are required in the iron-molybdenum cofactor (FeMo-co) biosynthetic pathway, the maturation of nitrogenase in a heterologous host can be divided in independent modules containing interacting proteins that function together to produce a specific intermediate. Therefore, nifB functional modules composed of a nifB variant, together with the A. vinelandii NifS and NifU proteins (for biosynthesis of NifB [Fe4S4] clusters) and the FdxN ferredoxin (for NifB function), were expressed in Nicotiana benthamiana chloroplasts and mitochondria. Three archaeal NifB proteins accumulated at high levels in soluble fractions of chloroplasts (Methanosarcina acetivorans and Methanocaldococcus infernus) or mitochondria (M. infernus and Methanothermobacter thermautotrophicus). These NifB proteins were shown to accept [Fe4S4] clusters from NifU and were functional in FeMo-co synthesis in vitro. The accumulation of significant levels of soluble and functional NifB proteins in chloroplasts and mitochondria is critical to engineering biological nitrogen fixation in plants. IMPORTANCE Biological nitrogen fixation is the conversion of inert atmospheric dinitrogen gas into nitrogen-reactive ammonia, a reaction catalyzed by the nitrogenase enzyme of diazotrophic bacteria and archaea. Because plants cannot fix their own nitrogen, introducing functional nitrogenase in cereals and other crop plants would reduce our strong dependency on N fertilizers. NifB is required for the biosynthesis of the active site cofactors of all nitrogenases, which arguably makes it the most important protein in global nitrogen fixation. NifB functionality is therefore a requisite to engineer a plant nitrogenase. The expression of nifB genes from a wide range of prokaryotes into the model diazotroph Azotobacter vinelandii shows a surprising level of genetic complementation suggestive of plasticity in the nitrogenase biosynthetic pathway. In addition, we obtained NifB proteins from both mitochondria and chloroplasts of tobacco that are functional in vitro after reconstitution by providing [Fe4S4] clusters from NifU, paving the way to nitrogenase cofactor biosynthesis in plants.

RevDate: 2022-08-12
CmpDate: 2022-06-14

Groux K, Verschueren A, Nanteau C, et al (2022)

Dynamic full-field optical coherence tomography allows live imaging of retinal pigment epithelium stress model.

Communications biology, 5(1):575.

Retinal degenerative diseases lead to the blindness of millions of people around the world. In case of age-related macular degeneration (AMD), the atrophy of retinal pigment epithelium (RPE) precedes neural dystrophy. But as crucial as understanding both healthy and pathological RPE cell physiology is for those diseases, no current technique allows subcellular in vivo or in vitro live observation of this critical cell layer. To fill this gap, we propose dynamic full-field OCT (D-FFOCT) as a candidate for live observation of in vitro RPE phenotype. In this way, we monitored primary porcine and human stem cell-derived RPE cells in stress model conditions by performing scratch assays. In this study, we quantified wound healing parameters on the stressed RPE, and observed different cell phenotypes, displayed by the D-FFOCT signal. In order to decipher the subcellular contributions to these dynamic profiles, we performed immunohistochemistry to identify which organelles generate the signal and found mitochondria to be the main contributor to D-FFOCT contrast. Altogether, D-FFOCT appears to be an innovative method to follow degenerative disease evolution and could be an appreciated method in the future for live patient diagnostics and to direct treatment choice.

RevDate: 2022-07-16

Ruiz D, Santibañez M, Lavín BA, et al (2022)

Evolution of Mitochondrially Derived Peptides Humanin and MOTSc, and Changes in Insulin Sensitivity during Early Gestation in Women with and without Gestational Diabetes.

Journal of clinical medicine, 11(11):.

Our purpose is to study the evolution of mitochondrially derived peptides (MDPs) and their relationship with changes in insulin sensitivity from the early stages of pregnancy in a cohort of pregnant women with and without gestational diabetes (GDM). MDPs (humanin and MOTSc) were assessed in the first and second trimesters of gestation in 28 pregnant women with gestational diabetes mellitus (GDM) and a subgroup of 45 pregnant women without GDM matched by BMI, age, previous gestations, and time of sampling. Insulin resistance (IR) was defined as a HOMA-IR index ≥70th percentile. We observed a significant reduction in both humanin and MOTSc levels from the first to the second trimesters of pregnancy. After adjusting for predefined variables, including BMI, statistically nonsignificant associations between lower levels of humanin and the occurrence of a high HOMA-IR index were obtained (adjusted OR = 2.63 and 3.14 for the first and second trimesters, linear p-trend 0.260 and 0.175, respectively). Regarding MOTSc, an association was found only for the second trimester: adjusted OR = 7.68 (95% CI 1.49-39.67), linear p-trend = 0.012. No significant associations were observed in humanin change with insulin resistance throughout pregnancy, but changes in MOTSc levels were significantly associated with HOMA-IR index: adjusted OR 3.73 (95% CI 1.03-13.50). In conclusion, MOTSc levels, especially a strong decrease from the first to second trimester of gestation, may be involved in increasing insulin resistance during early gestation.

RevDate: 2022-07-16
CmpDate: 2022-06-13

Cartalas J, Coudray L, A Gobert (2022)

How RNases Shape Mitochondrial Transcriptomes.

International journal of molecular sciences, 23(11):.

Mitochondria are the power houses of eukaryote cells. These endosymbiotic organelles of prokaryote origin are considered as semi-autonomous since they have retained a genome and fully functional gene expression mechanisms. These pathways are particularly interesting because they combine features inherited from the bacterial ancestor of mitochondria with characteristics that appeared during eukaryote evolution. RNA biology is thus particularly diverse in mitochondria. It involves an unexpectedly vast array of factors, some of which being universal to all mitochondria and others being specific from specific eukaryote clades. Among them, ribonucleases are particularly prominent. They play pivotal functions such as the maturation of transcript ends, RNA degradation and surveillance functions that are required to attain the pool of mature RNAs required to synthesize essential mitochondrial proteins such as respiratory chain proteins. Beyond these functions, mitochondrial ribonucleases are also involved in the maintenance and replication of mitochondrial DNA, and even possibly in the biogenesis of mitochondrial ribosomes. The diversity of mitochondrial RNases is reviewed here, showing for instance how in some cases a bacterial-type enzyme was kept in some eukaryotes, while in other clades, eukaryote specific enzymes were recruited for the same function.

RevDate: 2022-07-16
CmpDate: 2022-06-13

Eugenin E, Camporesi E, C Peracchia (2022)

Direct Cell-Cell Communication via Membrane Pores, Gap Junction Channels, and Tunneling Nanotubes: Medical Relevance of Mitochondrial Exchange.

International journal of molecular sciences, 23(11):.

The history of direct cell-cell communication has evolved in several small steps. First discovered in the 1930s in invertebrate nervous systems, it was thought at first to be an exception to the "cell theory", restricted to invertebrates. Surprisingly, however, in the 1950s, electrical cell-cell communication was also reported in vertebrates. Once more, it was thought to be an exception restricted to excitable cells. In contrast, in the mid-1960s, two startling publications proved that virtually all cells freely exchange small neutral and charged molecules. Soon after, cell-cell communication by gap junction channels was reported. While gap junctions are the major means of cell-cell communication, in the early 1980s, evidence surfaced that some cells might also communicate via membrane pores. Questions were raised about the possible artifactual nature of the pores. However, early in this century, we learned that communication via membrane pores exists and plays a major role in medicine, as the structures involved, "tunneling nanotubes", can rescue diseased cells by directly transferring healthy mitochondria into compromised cells and tissues. On the other hand, pathogens/cancer could also use these communication systems to amplify pathogenesis. Here, we describe the evolution of the discovery of these new communication systems and the potential therapeutic impact on several uncurable diseases.

RevDate: 2022-07-16
CmpDate: 2022-06-09

Tassé M, Choquette T, Angers A, et al (2022)

The longest mitochondrial protein in metazoans is encoded by the male-transmitted mitogenome of the bivalve Scrobicularia plana.

Biology letters, 18(6):20220122.

Cytochrome c oxidase subunit II (COX2) is one of the three mitochondrially encoded proteins of the complex IV of the respiratory chain that catalyses the reduction of oxygen to water. The cox2 gene spans about 690 base pairs in most animal species and produces a protein composed of approximately 230 amino acids. We discovered an extreme departure from this pattern in the male-transmitted mitogenome of the bivalve Scrobicularia plana with doubly uniparental inheritance (DUI) of mitochondrial DNA (mtDNA), which possesses an important in-frame insertion of approximately 4.8 kb in its cox2 gene. This feature-an enlarged male cox2 gene-is found in many species with DUI; the COX2 protein can be up to 420 amino acids long. Through RT-PCRs, immunoassays and comparative genetics, the evolution and functionality of this insertion in S. plana were characterized. The in-frame insertion is conserved among individuals from different populations and bears the signature of purifying selection seemingly indicating maintenance of functionality. Its transcription and translation were confirmed: this gene produces a polypeptide of 1892 amino acids, making it the largest metazoan COX2 protein known to date. We hypothesize that these extreme modifications in the COX2 protein affect the metabolism of mitochondria containing the male-transmitted mtDNA in Scrobicularia plana.

RevDate: 2022-06-16
CmpDate: 2022-06-16

Choudhury S, Ananthanarayanan V, KG Ayappa (2022)

Coupling of mitochondrial population evolution to microtubule dynamics in fission yeast cells: a kinetic Monte Carlo study.

Soft matter, 18(23):4483-4492.

Mitochondrial populations in cells are maintained by cycles of fission and fusion events. Perturbation of this balance has been observed in several diseases such as cancer and neurodegeneration. In fission yeast cells, the association of mitochondria with microtubules inhibits mitochondrial fission [Mehta et al., J. Biol. Chem., 2019, 294, 3385], illustrating the intricate coupling between mitochondria and the dynamic population of microtubules within the cell. In order to understand this coupling, we carried out kinetic Monte Carlo (KMC) simulations to predict the evolution of mitochondrial size distributions for different cases; wild-type cells, cells with short and long microtubules, and cells without microtubules. Comparisons are made with mitochondrial distributions reported in experiments with fission yeast cells. Using experimentally determined mitochondrial fission and fusion frequencies, simulations implemented without the coupling of microtubule dynamics predicted an increase in the mean number of mitochondria, equilibrating within 50 s. The mitochondrial length distribution in these models also showed a higher occurrence of shorter mitochondria, implying a greater tendency for fission, similar to the scenario observed in the absence of microtubules and cells with short microtubules. Interestingly, this resulted in overestimating the mean number of mitochondria and underestimating mitochondrial lengths in cells with wild-type and long microtubules. However, coupling mitochondria's fission and fusion events to the microtubule dynamics effectively captured the mitochondrial number and size distributions in wild-type and cells with long microtubules. Thus, the model provides greater physical insight into the temporal evolution of mitochondrial populations in different microtubule environments, allowing one to study both the short-time evolution as observed in the experiments (<5 minutes) as well as their transition towards a steady-state (>15 minutes). Our study illustrates the critical role of microtubules in mitochondrial dynamics and coupling microtubule growth and shrinkage dynamics is critical to predicting the evolution of mitochondrial populations within the cell.

RevDate: 2022-08-12
CmpDate: 2022-08-02

Simon M, Durand S, Ricou A, et al (2022)

APOK3, a pollen killer antidote in Arabidopsis thaliana.

Genetics, 221(4):.

The principles of heredity state that the two alleles carried by a heterozygote are equally transmitted to the progeny. However, genomic regions that escape this rule have been reported in many organisms. It is notably the case of genetic loci referred to as gamete killers, where one allele enhances its transmission by causing the death of the gametes that do not carry it. Gamete killers are of great interest, particularly to understand mechanisms of evolution and speciation. Although being common in plants, only a few, all in rice, have so far been deciphered to the causal genes. Here, we studied a pollen killer found in hybrids between two accessions of Arabidopsis thaliana. Exploring natural variation, we observed this pollen killer in many crosses within the species. Genetic analyses revealed that three genetically linked elements are necessary for pollen killer activity. Using mutants, we showed that this pollen killer works according to a poison-antidote model, where the poison kills pollen grains not producing the antidote. We identified the gene encoding the antidote, a chimeric protein addressed to mitochondria. De novo genomic sequencing in 12 natural variants with different behaviors regarding the pollen killer revealed a hyper variable locus, with important structural variations particularly in killer genotypes, where the antidote gene recently underwent duplications. Our results strongly suggest that the gene has newly evolved within A. thaliana. Finally, we identified in the protein sequence polymorphisms related to its antidote activity.

RevDate: 2022-06-30
CmpDate: 2022-06-08

Dawson NJ, GR Scott (2022)

Adaptive increases in respiratory capacity and O2 affinity of subsarcolemmal mitochondria from skeletal muscle of high-altitude deer mice.

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 36(7):e22391.

Aerobic energy demands have led to the evolution of complex mitochondrial reticula in highly oxidative muscles, but the extent to which metabolic challenges can be met with adaptive changes in physiology of specific mitochondrial fractions remains unresolved. We examined mitochondrial mechanisms supporting adaptive increases in aerobic performance in deer mice (Peromyscus maniculatus) adapted to the hypoxic environment at high altitude. High-altitude and low-altitude mice were born and raised in captivity, and exposed as adults to normoxia or hypobaric hypoxia (12 kPa O2 for 6-8 weeks). Subsarcolemmal and intermyofibrillar mitochondria were isolated from the gastrocnemius, and a comprehensive substrate titration protocol was used to examine mitochondrial physiology and O2 kinetics by high-resolution respirometry and fluorometry. High-altitude mice had greater yield, respiratory capacity for oxidative phosphorylation, and O2 affinity (lower P50) of subsarcolemmal mitochondria compared to low-altitude mice across environments, but there were no species difference in these traits in intermyofibrillar mitochondria. High-altitude mice also had greater capacities of complex II relative to complexes I + II and higher succinate dehydrogenase activities in both mitochondrial fractions. Exposure to chronic hypoxia reduced reactive oxygen species (ROS) emission in high-altitude mice but not in low-altitude mice. Our findings suggest that functional changes in subsarcolemmal mitochondria contribute to improving aerobic performance in hypoxia in high-altitude deer mice. Therefore, physiological variation in specific mitochondrial fractions can help overcome the metabolic challenges of life at high altitude.

RevDate: 2022-08-24
CmpDate: 2022-08-10

Hautekiet P, Saenen ND, Aerts R, et al (2022)

Higher buccal mtDNA content is associated with residential surrounding green in a panel study of primary school children.

Environmental research, 213:113551.

BACKGROUND: Mitochondria are known to respond to environmental stressors but whether green space is associated with mitochondrial abundance is unexplored. Furthermore, as exposures may affect health from early life onwards, we here evaluate if residential green space is associated with mitochondria DNA content (mtDNAc) in children.

METHODS: In primary schoolchildren (COGNAC study), between 2012 and 2014, buccal mtDNAc was repeatedly (three times) assessed using qPCR. Surrounding low (<3m), high (≥3m) and total (sum of low and high) green space within different radii (100m-1000m) from the residence and distance to the nearest large green space (>0.5ha) were estimated using a remote sensing derived map. Given the repeated measures design, we applied a mixed-effects model with school and subject as random effect while adjusting for a priori chosen fixed covariates.

RESULTS: mtDNAc was assessed in 246 children with a total of 436 measurements (mean age 10.3 years). Within a 1000m radius around the residential address, an IQR increment in low (11.0%), high (9.5%), and total (13.9%) green space was associated with a respectively 15.2% (95% CI: 7.2%-23.7%), 10.8% (95% CI: 4.5%-17.5%), and 13.4% (95% CI: 7.4%-19.7%) higher mtDNAc. Conversely, an IQR increment (11.6%) in agricultural area in the same radius was associated with a -3.4% (95% CI: 6.7% to -0.1%) lower mtDNAc. Finally, a doubling in distance to large green space was associated with a -5.2% (95% CI: 7.9 to -2.4%) lower mtDNAc.

CONCLUSION: To our knowledge, this is the first study evaluating associations between residential surrounding green space and mtDNAc in children. Our results showed that green space was associated with a higher mtDNAc in children, which indicates the importance of the early life environment. To what extent these findings contribute to later life health effects should be further examined.

RevDate: 2022-07-25
CmpDate: 2022-06-13

Bremer N, Tria FDK, Skejo J, et al (2022)

Ancestral State Reconstructions Trace Mitochondria But Not Phagocytosis to the Last Eukaryotic Common Ancestor.

Genome biology and evolution, 14(6):.

Two main theories have been put forward to explain the origin of mitochondria in eukaryotes: phagotrophic engulfment (undigested food) and microbial symbiosis (physiological interactions). The two theories generate mutually exclusive predictions about the order in which mitochondria and phagocytosis arose. To discriminate the alternatives, we have employed ancestral state reconstructions (ASR) for phagocytosis as a trait, phagotrophy as a feeding habit, the presence of mitochondria, the presence of plastids, and the multinucleated organization across major eukaryotic lineages. To mitigate the bias introduced by assuming a particular eukaryotic phylogeny, we reconstructed the appearance of these traits across 1789 different rooted gene trees, each having species from opisthokonts, mycetozoa, hacrobia, excavate, archeplastida, and Stramenopiles, Alveolates and Rhizaria. The trees reflect conflicting relationships and different positions of the root. We employed a novel phylogenomic test that summarizes ASR across trees which reconstructs a last eukaryotic common ancestor that possessed mitochondria, was multinucleated, lacked plastids, and was non-phagotrophic as well as non-phagocytic. This indicates that both phagocytosis and phagotrophy arose subsequent to the origin of mitochondria, consistent with findings from comparative physiology. Furthermore, our ASRs uncovered multiple origins of phagocytosis and of phagotrophy across eukaryotes, indicating that, like wings in animals, these traits are useful but neither ancestral nor homologous across groups. The data indicate that mitochondria preceded the origin of phagocytosis, such that phagocytosis cannot have been the mechanism by which mitochondria were acquired.

RevDate: 2022-07-19
CmpDate: 2022-06-02

Calatrava V, Stephens TG, Gabr A, et al (2022)

Retrotransposition facilitated the establishment of a primary plastid in the thecate amoeba Paulinella.

Proceedings of the National Academy of Sciences of the United States of America, 119(23):e2121241119.

The evolution of eukaryotic life was predicated on the development of organelles such as mitochondria and plastids. During this complex process of organellogenesis, the host cell and the engulfed prokaryote became genetically codependent, with the integration of genes from the endosymbiont into the host nuclear genome and subsequent gene loss from the endosymbiont. This process required that horizontally transferred genes become active and properly regulated despite inherent differences in genetic features between donor (endosymbiont) and recipient (host). Although this genetic reorganization is considered critical for early stages of organellogenesis, we have little knowledge about the mechanisms governing this process. The photosynthetic amoeba Paulinella micropora offers a unique opportunity to study early evolutionary events associated with organellogenesis and primary endosymbiosis. This amoeba harbors a “chromatophore,” a nascent photosynthetic organelle derived from a relatively recent cyanobacterial association (∼120 million years ago) that is independent of the evolution of primary plastids in plants (initiated ∼1.5 billion years ago). Analysis of the genome and transcriptome of Paulinella revealed that retrotransposition of endosymbiont-derived nuclear genes was critical for their domestication in the host. These retrocopied genes involved in photoprotection in cyanobacteria became expanded gene families and were “rewired,” acquiring light-responsive regulatory elements that function in the host. The establishment of host control of endosymbiont-derived genes likely enabled the cell to withstand photo-oxidative stress generated by oxygenic photosynthesis in the nascent organelle. These results provide insights into the genetic mechanisms and evolutionary pressures that facilitated the metabolic integration of the host–endosymbiont association and sustained the evolution of a photosynthetic organelle.

RevDate: 2022-09-06
CmpDate: 2022-06-02

Li M, Chen WT, Zhang QL, et al (2022)

Mitochondrial phylogenomics provides insights into the phylogeny and evolution of spiders (Arthropoda: Araneae).

Zoological research, 43(4):566-584.

Spiders are among the most varied terrestrial predators, with highly diverse morphology, ecology, and behavior. Morphological and molecular data have greatly contributed to advances in the phylogeny and evolutionary dynamics of spiders. Here, we performed comprehensive mitochondrial phylogenomics analysis on 78 mitochondrial genomes (mitogenomes) representing 29 families; of these, 23 species from eight families were newly generated. Mesothelae retained the same gene arrangement as the arthropod ancestor (Limulus polyphemus), while Opisthothelae showed extensive rearrangement, with 12 rearrangement types in transfer RNAs (tRNAs) and control region. Most spider tRNAs were extremely truncated and lacked typical dihydrouridine or TΨC arms, showing high tRNA structural diversity; in particular, trnS1 exhibited anticodon diversity across the phylogeny. The evolutionary rates of mitochondrial genes were potentially associated with gene rearrangement or truncated tRNAs. Both mitogenomic sequences and rearrangements possessed phylogenetic characteristics, providing a robust backbone for spider phylogeny, as previously reported. The monophyly of suborder, infraorder, retrolateral tibial apophysis clade, and families (except for Pisauridae) was separately supported, and high-level relationships were resolved as (Mesothelae, (Mygalomorphae, (Entelegynae, (Synspermiata, Hypochilidae)))). The phylogenetic positions of several families were also resolved (e.g., Eresidae, Oecobiidae and Titanoecidae). Two reconstructions of ancestral web type obtained almost identical results, indicating that the common ancestor of spiders likely foraged using a silk-lined burrow. This study, the largest mitochondrial phylogenomics analysis of spiders to date, highlights the usefulness of mitogenomic data not only for providing efficient phylogenetic signals for spider phylogeny, but also for characterizing trait diversification in spider evolution.

RevDate: 2022-07-16
CmpDate: 2022-06-02

Kodama Y, M Fujishima (2022)

Endosymbiotic Chlorella variabilis reduces mitochondrial number in the ciliate Paramecium bursaria.

Scientific reports, 12(1):8216.

Extant symbioses illustrate endosymbiosis is a driving force for evolution and diversification. In the ciliate Paramecium bursaria, the endosymbiotic alga Chlorella variabilis in perialgal vacuole localizes beneath the host cell cortex by adhesion between the perialgal vacuole membrane and host mitochondria. We investigated whether host mitochondria are also affected by algal endosymbiosis. Transmission electron microscopy of host cells showed fewer mitochondria beneath the algae-bearing host cell cortex than that of alga-free cells. To compare the density and distribution of host mitochondria with or without symbiotic algae, we developed a monoclonal antibody against Paramecium mitochondria. Immunofluorescence microscopy with the monoclonal antibody showed that the mitochondrial density of the algae-bearing P. bursaria was significantly lower than that of the alga-free cells. The total cell protein concentration of alga-free P. bursaria cells was approximately 1.8-fold higher than that of algae-bearing cells, and the protein content of mitochondria was significantly higher in alga-free cells than that in the algae-bearing cells. These results corresponded with those obtained by transmission electron and immunofluorescence microscopies. This paper shows that endosymbiotic algae affect reduced mitochondrial number in the host P. bursaria significantly.

RevDate: 2022-06-22
CmpDate: 2022-06-21

Jiang YJ, Jin J, Nan QY, et al (2022)

Coenzyme Q10 attenuates renal fibrosis by inhibiting RIP1-RIP3-MLKL-mediated necroinflammation via Wnt3α/β-catenin/GSK-3β signaling in unilateral ureteral obstruction.

International immunopharmacology, 108:108868.

OBJECTIVE: Coenzyme Q10 (CoQ10) protects against various types of injury, but its role in preventing renal scarring in chronic kidney disease remains an open question. Herein, we evaluated whether CoQ10 attenuates renal fibrosis by interfering with necroinflammation in a rat model of unilateral ureteral obstruction (UUO) and in vitro.

METHODS: Rats with UUO were treated daily with CoQ10 or an RIP inhibitor (necrostatin-1 or GSK872) for 7 days. The influence of CoQ10 on renal injury caused by UUO was evaluated by histopathology and analysis of gene expression, oxidative stress, intracellular organelles, apoptosis, and Wnt3α/β-catenin/GSK-3β signaling·H2O2-exposed human kidney (HK-2) cells were also examined after treatment with CoQ10 or an RIP inhibitor.

RESULTS: UUO induced marked renal tubular necrosis, upregulation of RIP1-RIP3-MLKL axis proteins, activation of the NLRP3 inflammasome, and evolution of renal fibrosis. UUO-induced oxidative stress evoked excessive endoplasmic reticulum stress and mitochondrial dysfunction, which triggered apoptotic cell death through Wnt3α/β-catenin/GSK-3β signaling. All of these effects were mitigated by CoQ10 or an RIP inhibitor. In H2O2-treated HK-2 cells, CoQ10 or an RIP inhibitor suppressed the expression of RIP1-RIP3-MLKL proteins and pyroptosis-related cytokines, and hindered the production of intracellular reactive oxygen species as shown by MitoSOX Red staining and apoptotic cell death but increased cell viability. The CoQ10 or Wnt/β-catenin inhibitor ICG-001 deactivated H2O2-stimulated activation of Wnt3α/β-catenin/GSK-3β signaling.

CONCLUSION: These findings suggest that CoQ10 attenuates renal fibrosis by inhibiting RIP1-RIP3-MLKL-mediated necroinflammation via Wnt3α/β-catenin/GSK-3β signaling in UUO.

RevDate: 2022-07-16
CmpDate: 2022-06-02

Zhang L, Liu K, Zhuan Q, et al (2022)

Mitochondrial Calcium Disorder Affects Early Embryonic Development in Mice through Regulating the ERK/MAPK Pathway.

Oxidative medicine and cellular longevity, 2022:8221361.

The homeostasis of mitochondrial calcium ([Ca2+]mt) in oocytes plays a critical role in maintaining normal reproductive cellular progress such as meiosis. However, little is known about the association between [Ca2+]mt homeostasis and early embryonic development. Two in vitro mouse MII oocyte models were established by using a specific agonist or inhibitor targeting mitochondrial calcium uniporters (MCU) to upregulate or downregulate [Ca2+]mt concentrations. The imbalance of [Ca2+]mt in MII oocytes causes mitochondrial dysfunction and morphological abnormity, leading to an abnormal spindle/chromosome structure. Oocytes in drug-treated groups are less likely to develop into blastocyst during in vitro culture. Abnormal [Ca2+]mt concentrations in oocytes hindered epigenetic modification and regulated mitogen-activated protein kinase (MAPK) signaling that is associated with gene expression. We also found that MAPK/ERK signaling is regulating DNA methylation in MII oocytes to modulate epigenetic modification. These data provide a new insight into the protective role of [Ca2+]mt homeostasis in early embryonic development and also demonstrate a new mechanism of MAPK signaling regulated by [Ca2+]mt that influences epigenetic modification.

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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.

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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.

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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.

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