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Sakamoto F, Kanamori S, Díaz LM, Cádiz A, Ishii Y, Yamaguchi K, Shigenobu S, Nakayama T, Makino T, Kawata M. Detection of evolutionary conserved and accelerated genomic regions related to adaptation to thermal niches in Anolis lizards. Ecol Evol 2024; 14:e11117. [PMID: 38455144 PMCID: PMC10920033 DOI: 10.1002/ece3.11117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 02/18/2024] [Accepted: 02/22/2024] [Indexed: 03/09/2024] Open
Abstract
Understanding the genetic basis for adapting to thermal environments is important due to serious effects of global warming on ectothermic species. Various genes associated with thermal adaptation in lizards have been identified mainly focusing on changes in gene expression or the detection of positively selected genes using coding regions. Only a few comprehensive genome-wide analyses have included noncoding regions. This study aimed to identify evolutionarily conserved and accelerated genomic regions using whole genomes of eight Anolis lizard species that have repeatedly adapted to similar thermal environments in multiple lineages. Evolutionarily conserved genomic regions were extracted as regions with overall sequence conservation (regions with fewer base substitutions) across all lineages compared with the neutral model. Genomic regions that underwent accelerated evolution in the lineage of interest were identified as those with more base substitutions in the target branch than in the entire background branch. Conserved elements across all branches were relatively abundant in "intergenic" genomic regions among noncoding regions. Accelerated regions (ARs) of each lineage contained a significantly greater proportion of noncoding RNA genes than the entire multiple alignment. Common genes containing ARs within 5 kb of their vicinity in lineages with similar thermal habitats were identified. Many genes associated with circadian rhythms and behavior were found in hot-open and cool-shaded habitat lineages. These genes might play a role in contributing to thermal adaptation and assist future studies examining the function of genes involved in thermal adaptation via genome editing.
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Affiliation(s)
- Fuku Sakamoto
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
| | | | - Luis M. Díaz
- National Museum of Natural History of CubaHavanaCuba
| | - Antonio Cádiz
- Faculty of BiologyUniversity of HavanaHavanaCuba
- Present address:
Department of BiologyUniversity of MiamiCoral GablesFloridaUSA
| | - Yuu Ishii
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
| | | | - Shuji Shigenobu
- Trans‐Omics FacilityNational Institute for Basic BiologyOkazakiJapan
- Department of Basic Biology, School of Life ScienceThe Graduate University for Advanced Studies, SOKENDAIOkazakiJapan
| | - Takuro Nakayama
- Division of Life Sciences, Center for Computational SciencesUniversity of TsukubaTsukubaJapan
| | - Takashi Makino
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
| | - Masakado Kawata
- Graduate School of Life SciencesTohoku UniversitySendaiJapan
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Zhao D, Zhang S, Chen J, Zhao J, An P, Xiang H. Members of the class Candidatus Ordosarchaeia imply an alternative evolutionary scenario from methanogens to haloarchaea. ISME J 2024; 18:wrad033. [PMID: 38366248 PMCID: PMC10873845 DOI: 10.1093/ismejo/wrad033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/05/2023] [Accepted: 12/19/2023] [Indexed: 02/18/2024]
Abstract
The origin of methanogenesis can be traced to the common ancestor of non-DPANN archaea, whereas haloarchaea (or Halobacteria) are believed to have evolved from a methanogenic ancestor through multiple evolutionary events. However, due to the accelerated evolution and compositional bias of proteins adapting to hypersaline habitats, Halobacteria exhibit substantial evolutionary divergence from methanogens, and the identification of the closest methanogen (either Methanonatronarchaeia or other taxa) to Halobacteria remains a subject of debate. Here, we obtained five metagenome-assembled genomes with high completeness from soda-saline lakes on the Ordos Plateau in Inner Mongolia, China, and we proposed the name Candidatus Ordosarchaeia for this novel class. Phylogenetic analyses revealed that Ca. Ordosarchaeia is firmly positioned near the median position between the Methanonatronarchaeia and Halobacteria-Hikarchaeia lineages. Functional predictions supported the transitional status of Ca. Ordosarchaeia with the metabolic potential of nonmethanogenic and aerobic chemoheterotrophy, as did remnants of the gene sequences of methylamine/dimethylamine/trimethylamine metabolism and coenzyme M biosynthesis. Based on the similarity of the methyl-coenzyme M reductase genes mcrBGADC in Methanonatronarchaeia with the phylogenetically distant methanogens, an alternative evolutionary scenario is proposed, in which Methanonatronarchaeia, Ca. Ordosarchaeia, Ca. Hikarchaeia, and Halobacteria share a common ancestor that initially lost mcr genes. However, certain members of Methanonatronarchaeia subsequently acquired mcr genes through horizontal gene transfer from distantly related methanogens. This hypothesis is supported by amalgamated likelihood estimation, phylogenetic analysis, and gene arrangement patterns. Altogether, Ca. Ordosarchaeia genomes clarify the sisterhood of Methanonatronarchaeia with Halobacteria and provide new insights into the evolution from methanogens to haloarchaea.
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Affiliation(s)
- Dahe Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shengjie Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Junyu Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Juanjuan Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Peng An
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, Sichuan Normal University, Sichuan 610068, China
| | - Hua Xiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing 101408, China
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Ong JY, Swidah R, Monti M, Schindler D, Dai J, Cai Y. SCRaMbLE: A Study of Its Robustness and Challenges through Enhancement of Hygromycin B Resistance in a Semi-Synthetic Yeast. Bioengineering (Basel) 2021; 8:42. [PMID: 33806931 DOI: 10.3390/bioengineering8030042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/17/2021] [Accepted: 03/20/2021] [Indexed: 11/21/2022] Open
Abstract
Recent advances in synthetic genomics launched the ambitious goal of generating the first synthetic designer eukaryote, based on the model organism Saccharomyces cerevisiae (Sc2.0). Excitingly, the Sc2.0 project is now nearing its completion and SCRaMbLE, an accelerated evolution tool implemented by the integration of symmetrical loxP sites (loxPSym) downstream of almost every non-essential gene, is arguably the most applicable synthetic genome-wide alteration to date. The SCRaMbLE system offers the capability to perform rapid genome diversification, providing huge potential for targeted strain improvement. Here we describe how SCRaMbLE can evolve a semi-synthetic yeast strain housing the synthetic chromosome II (synII) to generate hygromycin B resistant genotypes. Exploiting long-read nanopore sequencing, we show that all structural variations are due to recombination between loxP sites, with no off-target effects. We also highlight a phenomenon imposed on SCRaMbLE termed “essential raft”, where a fragment flanked by a pair of loxPSym sites can move within the genome but cannot be removed due to essentiality restrictions. Despite this, SCRaMbLE was able to explore the genomic space and produce alternative structural compositions that resulted in an increased hygromycin B resistance in the synII strain. We show that among the rearrangements generated via SCRaMbLE, deletions of YBR219C and YBR220C contribute to hygromycin B resistance phenotypes. However, the hygromycin B resistance provided by SCRaMbLEd genomes showed significant improvement when compared to corresponding single deletions, demonstrating the importance of the complex structural variations generated by SCRaMbLE to improve hygromycin B resistance. We anticipate that SCRaMbLE and its successors will be an invaluable tool to predict and evaluate the emergence of antibiotic resistance in yeast.
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Ferris E, Gregg C. Parallel Accelerated Evolution in Distant Hibernators Reveals Candidate Cis Elements and Genetic Circuits Regulating Mammalian Obesity. Cell Rep 2019; 29:2608-2620.e4. [PMID: 31775032 DOI: 10.1016/j.celrep.2019.10.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/21/2019] [Accepted: 10/24/2019] [Indexed: 12/15/2022] Open
Abstract
Obesity is a clinical problem and an important adaptation in many species. Hibernating mammals, for example, become obese, insulin resistant, and hyperinsulinemic to store fat. Here, we combine comparative phylogenomics with large-scale human genome data to uncover candidate cis elements and genetic circuits in different cell types. The Fat Mass and Obesity (FTO) locus, the strongest genetic risk factor for human obesity, is an enriched site for hibernator pARs. Our results uncover noncoding cis elements with putative roles in obesity and hibernation. Obesity is a clinical problem but also an important adaptation in hibernators. By using comparative genomics approaches to analyze the genomes of hibernators from different clades and contrasting the results with human obesity risk loci, Ferris and Gregg found 364 conserved cis elements with putative roles in regulating obesity and hibernation.
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Yang L, Jiang H, Chen J, Lei Y, Sun N, Lv W, Near TJ, He S. Comparative Genomics Reveals Accelerated Evolution of Fright Reaction Genes in Ostariophysan Fishes. Front Genet 2019; 10:1283. [PMID: 31921316 PMCID: PMC6936194 DOI: 10.3389/fgene.2019.01283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 11/21/2019] [Indexed: 11/13/2022] Open
Abstract
The ostariophysian fishes are the most species-rich clade in freshwaters. This diversification has been suggested to be associated with the fright reaction presented in most ostariophysians. However, the genetic forces that underlie fright reaction remains poorly understood. In the present study, through integrating behavioral, physiological, transcriptomic, and evolutionary genomic analyses, we found that the fright reaction has a broad impact on zebrafish at multiple levels, including changes in swimming behaviors, cortisol levels, and gene expression patterns. In total, 1,555 and 1,599 differentially expressed genes were identified in olfactory mucosae and brain of zebrafish, respectively, with a greater number upregulated after the fright reaction. Functional annotation showed that response to stress and signal transduction were strongly represented, which is directly associated with the fright reaction. These differentially expressed genes were shown to be evolved accelerated under the influence of positive selection, indicating that protein-coding evolution has played a major role in fright reaction. We found the basal vomeronasal type 2 receptors (v2r) gene, v2rl1, displayed significantly decrease expression after fright reaction, which suggests that v2rs may be important to detect the alarm substance and induce the fright reaction. Collectively, based on our transcriptome and evolutionary genomics analyses, we suggest that transcriptional plasticity of gene may play an important role in fright reaction in ostariophysian fishes.
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Affiliation(s)
- Liandong Yang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Haifeng Jiang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Juan Chen
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yi Lei
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Ning Sun
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wenqi Lv
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Thomas J Near
- Department of Ecology and Evolutionary Biology and Peabody Museum of Natural History, Yale University, New Haven, CT, United States
| | - Shunping He
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Institute of Deep Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
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Chijiwa T, Inamaru K, Takeuchi A, Maeda M, Yamaguchi K, Shibata H, Hattori S, Oda-Ueda N, Ohno M. Unique structure (construction and configuration) and evolution of the array of small serum protein genes of Protobothrops flavoviridis snake. Biosci Rep 2019; 39:BSR20190560. [PMID: 31213576 DOI: 10.1042/BSR20190560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/06/2019] [Accepted: 06/17/2019] [Indexed: 11/27/2022] Open
Abstract
The nucleotide sequence of Protobothrops flavoviridis (Pf) 30534 bp genome segment which contains genes encoding small serum proteins (SSPs) was deciphered. The genome segment contained five SSP genes (PfSSPs), PfSSP-4, PfSSP-5, PfSSP-1, PfSSP-2, and PfSSP-3 in this order and had characteristic configuration and constructions of the particular nucleotide sequences inserted. Comparison between the configurations of the inserted chicken repeat-1 (CR1) fragments of P. flavoviridis and Ophiophagus hannah (Oh) showed that the nucleotide segment encompassing from PfSSP-1 to PfSSP-2 was inverted. The inactive form of PfSSP-1, named PfSSP-1δ(Ψ), found in the intergenic region (I-Reg) between PfSSP-5 and PfSSP-1 had also been destroyed by insertions of the plural long interspersed nuclear elements (LINEs) and DNA transposons. The L2 LINE inserted into the third intron or the particular repetitive sequences inserted into the second intron structurally divided five PfSSPs into two subgroups, the Long SSP subgroup of PfSSP-1, PfSSP-2 and PfSSP-5 or the Short SSP subgroup of PfSSP-3 and PfSSP-4. The mathematical analysis also showed that PfSSPs of the Long SSP subgroup evolved alternately in an accelerated and neutral manner, whereas those of the Short SSP subgroup evolved in an accelerated manner. Moreover, the ortholog analysis of SSPs of various snakes showed that the evolutionary emerging order of SSPs was as follows: SSP-5, SSP-4, SSP-2, SSP-1, and SSP-3. The unique interpretation about accelerated evolution and the novel idea that the transposable elements such as LINEs and DNA transposons are involved in maintaining the host genome besides its own transposition natures were proposed.
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Ferris E, Abegglen LM, Schiffman JD, Gregg C. Accelerated Evolution in Distinctive Species Reveals Candidate Elements for Clinically Relevant Traits, Including Mutation and Cancer Resistance. Cell Rep 2019. [PMID: 29514101 PMCID: PMC6294302 DOI: 10.1016/j.celrep.2018.02.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The identity of most functional elements in the mammalian genome and the phenotypes they impact are unclear. Here, we perform a genomewide comparative analysis of patterns of accelerated evolution in species with highly distinctive traits to discover candidate functional elements for clinically important phenotypes. We identify accelerated regions (ARs) in the elephant, hibernating bat, orca, dolphin, naked mole rat, and thirteen-lined ground squirrel lineages in mammalian conserved regions, uncovering ~33,000 elements that bind hundreds of different regulatory proteins in humans and mice. ARs in the elephant, the largest land mammal, are uniquely enriched near elephant DNA damage response genes. The genomic hotspot for elephant ARs is the E3 ligase subunit of the Fanconi anemia complex, a master regulator of DNA repair. Additionally, ARs in the six species are associated with specific human clinical phenotypes that have apparent concordance with overt traits in each species.
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Affiliation(s)
- Elliott Ferris
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA
| | - Lisa M Abegglen
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84132-3401, USA; Huntsman Cancer Institute, Salt Lake City, UT, USA
| | - Joshua D Schiffman
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84132-3401, USA; Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84132-3401, USA; Huntsman Cancer Institute, Salt Lake City, UT, USA
| | - Christopher Gregg
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA; Department of Human Genetics, University of Utah, Salt Lake City, UT 84132-3401, USA; New York Stem Cell Foundation, New York, NY, USA.
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Lang KS, Hall AN, Merrikh CN, Ragheb M, Tabakh H, Pollock AJ, Woodward JJ, Dreifus JE, Merrikh H. Replication-Transcription Conflicts Generate R-Loops that Orchestrate Bacterial Stress Survival and Pathogenesis. Cell 2017; 170:787-799.e18. [PMID: 28802046 DOI: 10.1016/j.cell.2017.07.044] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 05/09/2017] [Accepted: 07/25/2017] [Indexed: 12/31/2022]
Abstract
Replication-transcription collisions shape genomes, influence evolution, and promote genetic diseases. Although unclear why, head-on transcription (lagging strand genes) is especially disruptive to replication and promotes genomic instability. Here, we find that head-on collisions promote R-loop formation in Bacillus subtilis. We show that pervasive R-loop formation at head-on collision regions completely blocks replication, elevates mutagenesis, and inhibits gene expression. Accordingly, the activity of the R-loop processing enzyme RNase HIII at collision regions is crucial for stress survival in B. subtilis, as many stress response genes are head-on to replication. Remarkably, without RNase HIII, the ability of the intracellular pathogen Listeria monocytogenes to infect and replicate in hosts is weakened significantly, most likely because many virulence genes are head-on to replication. We conclude that the detrimental effects of head-on collisions stem primarily from excessive R-loop formation and that the resolution of these structures is critical for bacterial stress survival and pathogenesis.
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Abstract
Superfamily Hominoidea, which consists of Hominidae (humans and great apes) and Hylobatidae (gibbons), is well-known for sharing human-like characteristics, however, the genomic origins of these shared unique phenotypes have mainly remained elusive. To decipher the underlying genomic basis of Hominoidea-restricted phenotypes, we identified and characterized Hominoidea-restricted highly conserved noncoding sequences (HCNSs) that are a class of potential regulatory elements which may be involved in evolution of lineage-specific phenotypes. We discovered 679 such HCNSs from human, chimpanzee, gorilla, orangutan and gibbon genomes. These HCNSs were demonstrated to be under purifying selection but with lineage-restricted characteristics different from old CNSs. A significant proportion of their ancestral sequences had accelerated rates of nucleotide substitutions, insertions and deletions during the evolution of common ancestor of Hominoidea, suggesting the intervention of positive Darwinian selection for creating those HCNSs. In contrary to enhancer elements and similar to silencer sequences, these Hominoidea-restricted HCNSs are located in close proximity of transcription start sites. Their target genes are enriched in the nervous system, development and transcription, and they tend to be remotely located from the nearest coding gene. Chip-seq signals and gene expression patterns suggest that Hominoidea-restricted HCNSs are likely to be functional regulatory elements by imposing silencing effects on their target genes in a tissue-restricted manner during fetal brain development. These HCNSs, emerged through adaptive evolution and conserved through purifying selection, represent a set of promising targets for future functional studies of the evolution of Hominoidea-restricted phenotypes.
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Affiliation(s)
- Morteza Mahmoudi Saber
- Division of Population Genetics, National Institute of Genetics, Mishima, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan
| | - Naruya Saitou
- Division of Population Genetics, National Institute of Genetics, Mishima, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan
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Abstract
We previously discovered that lagging strand genes evolve faster in Bacillus subtilis (and potentially other bacteria). Lagging strand genes are transcribed in the head-on orientation with respect to DNA replication, leading to collisions between the two machineries that stall replication and can destabilize genomes. Our previous work indicated that the increased mutagenesis of head-on genes depends on transcription-coupled repair and the activity of an error prone polymerase which is likely activated in response to these collisions. Recently, it was proposed that sequence context is a major contributor to the increased mutagenesis and evolution of head-on genes. These models are based on laboratory-based evolution experiments performed in B. subtilis. However, critical evolutionary analyses of naturally occurring single nucleotide polymorphisms (SNPs) in wild strains were not performed. Using the genomic sequences from nine closely related wild B. subtilis strains, we analyzed over 200,000 naturally occurring SNPs as a proxy for natural mutation patterns for all genes and in particular, head-on genes. Our analysis suggests that (frame-independent) triplet sequence context can impact mutation rates: certain triplet sequences (TAG, CCC, CTA, and ACC) accumulate SNPs at a higher rate and are depleted from the genome. However, the triplet sequences previously identified as mutagenic in laboratory experiments (CCG, GCG, and CAC) do not have an elevated rate of SNP accumulation and are not depleted from the genome. Importantly, dN/dS analyses indicate that the accelerated evolution of head-on genes is not dependent on any particular triplet sequence. Thus, in agreement with our previous results, mutagenic transcription-coupled repair, rather than sequence context, is sufficient to explain the accelerated evolution of head-on genes.
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Affiliation(s)
| | - Eli Weiss
- Microbiology Department, University of Washington, Seattle, USA
| | - Houra Merrikh
- Microbiology Department, University of Washington, Seattle, USA
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Abstract
Accelerated evolution of regulatory sequence can alter the expression pattern of target genes, and cause phenotypic changes. In this study, we used DNase I hypersensitive sites (DHSs) to annotate putative regulatory sequences in the human genome, and conducted a genome-wide analysis of the effects of accelerated evolution on regulatory sequences. Working under the assumption that local ancient repeat elements of DHSs are under neutral evolution, we discovered that ∼0.44% of DHSs are under accelerated evolution (ace-DHSs). We found that ace-DHSs tend to be more active than background DHSs, and are strongly associated with epigenetic marks of active transcription. The target genes of ace-DHSs are significantly enriched in neuron-related functions, and their expression levels are positively selected in the human brain. Thus, these lines of evidences strongly suggest that accelerated evolution on regulatory sequences plays important role in the evolution of human-specific phenotypes.
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Affiliation(s)
- Xinran Dong
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai, P.R. China
| | - Xiao Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai, P.R. China
| | - Feng Zhang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai, P.R. China
| | - Weidong Tian
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biostatistics and Computational Biology, School of Life Sciences, Fudan University, Shanghai, P.R. China Children's Hospital of Fudan University, Shanghai, P.R. China
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Abstract
Family Hominidae, which includes humans and great apes, is recognized for unique complex social behavior and intellectual abilities. Despite the increasing genome data, however, the genomic origin of its phenotypic uniqueness has remained elusive. Clade-specific genes and highly conserved noncoding sequences (HCNSs) are among the high-potential evolutionary candidates involved in driving clade-specific characters and phenotypes. On this premise, we analyzed whole genome sequences along with gene orthology data retrieved from major DNA databases to find Hominidae-specific (HS) genes and HCNSs. We discovered that Down syndrome critical region 4 (DSCR4) is the only experimentally verified gene uniquely present in Hominidae. DSCR4 has no structural homology to any known protein and was inferred to have emerged in several steps through LTR/ERV1, LTR/ERVL retrotransposition, and transversion. Using the genomic distance as neutral evolution threshold, we identified 1,658 HS HCNSs. Polymorphism coverage and derived allele frequency analysis of HS HCNSs showed that these HCNSs are under purifying selection, indicating that they may harbor important functions. They are overrepresented in promoters/untranslated regions, in close proximity of genes involved in sensory perception of sound and developmental process, and also showed a significantly lower nucleosome occupancy probability. Interestingly, many ancestral sequences of the HS HCNSs showed very high evolutionary rates. This suggests that new functions emerged through some kind of positive selection, and then purifying selection started to operate to keep these functions.
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Affiliation(s)
- Morteza Mahmoudi Saber
- Department of Biological Sciences, Graduate School of Science, University of Tokyo Division of Population Genetics, National Institute of Genetics, Mishima, Japan
| | - Isaac Adeyemi Babarinde
- Division of Population Genetics, National Institute of Genetics, Mishima, Japan Department of Genetics, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan
| | - Nilmini Hettiarachchi
- Division of Population Genetics, National Institute of Genetics, Mishima, Japan Department of Genetics, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan
| | - Naruya Saitou
- Department of Biological Sciences, Graduate School of Science, University of Tokyo Division of Population Genetics, National Institute of Genetics, Mishima, Japan Department of Genetics, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan
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Abstract
Triplophysa fishes are the primary component of the fish fauna on the Tibetan Plateau and are well adapted to the high-altitude environment. Despite the importance of Triplophysa fishes on the plateau, the genetic mechanisms of the adaptations of these fishes to this high-altitude environment remain poorly understood. In this study, we generated the transcriptome sequences for three Triplophysa fishes, that is, Triplophysa siluroides, Triplophysa scleroptera, and Triplophysa dalaica, and used these and the previously available transcriptome and genome sequences from fishes living at low altitudes to identify potential genetic mechanisms for the high-altitude adaptations in Triplophysa fishes. An analysis of 2,269 orthologous genes among cave fish (Astyanax mexicanus), zebrafish (Danio rerio), large-scale loach (Paramisgurnus dabryanus), and Triplophysa fishes revealed that each of the terminal branches of the Triplophysa fishes had a significantly higher ratio of nonsynonymous to synonymous substitutions than that of the branches of the fishes from low altitudes, which provided consistent evidence for genome-wide rapid evolution in the Triplophysa genus. Many of the GO (Gene Ontology) categories associated with energy metabolism and hypoxia response exhibited accelerated evolution in the Triplophysa fishes compared with the large-scale loach. The genes that exhibited signs of positive selection and rapid evolution in the Triplophysa fishes were also significantly enriched in energy metabolism and hypoxia response categories. Our analysis identified widespread Triplophysa-specific nonsynonymous mutations in the fast evolving genes and positively selected genes. Moreover, we detected significant evidence of positive selection in the HIF (hypoxia-inducible factor)-1A and HIF-2B genes in Triplophysa fishes and found that the Triplophysa-specific nonsynonymous mutations in the HIF-1A and HIF-2B genes were associated with functional changes. Overall, our study provides new insights into the adaptations and evolution of fishes in the high-altitude environment of the Tibetan Plateau and complements previous findings on the adaptations of mammals and birds to high altitudes.
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Affiliation(s)
- Ying Wang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China University of the Chinese Academy of Sciences, Beijing, China
| | - Liandong Yang
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China University of the Chinese Academy of Sciences, Beijing, China
| | - Kun Zhou
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, China
| | - Yanping Zhang
- Gansu Key Laboratory of Cold Water Fishes Germplasm Resources and Genetics Breeding, Gansu Fishers Research Institute, Lanzhou, China
| | - Zhaobin Song
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, China
| | - Shunping He
- The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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Nikaido M, Ota T, Hirata T, Suzuki H, Satta Y, Aibara M, Mzighani SI, Sturmbauer C, Hagino-Yamagishi K, Okada N. Multiple episodic evolution events in V1R receptor genes of East-African cichlids. Genome Biol Evol 2014; 6:1135-44. [PMID: 24803573 PMCID: PMC4040994 DOI: 10.1093/gbe/evu086] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Fish use olfaction to detect a variety of nonvolatile chemical signals, and thus, this sense is key to survival and communication. However, the contribution of the olfactory sense to social—especially reproductive—interactions in cichlids is still controversial. To obtain insights into this issue, we investigated the genes encoding V1Rs—possible candidates for reproductive pheromone receptors—among East-African cichlids. Interestingly, we found an excess of nonsynonymous over synonymous substitutions in four of six V1R genes in multiple cichlid lineages. First, we found that highly dimorphic V1R2 allele groups were shared among the cichlids inhabiting all East-African Great Lakes emerged through the episodic accumulation of the nonsynonymous substitutions prior to the radiation of the Lake Tanganyika species flock. We further detected such episodic events in V1R1 of the tribe Tropheini, and in V1R3 and V1R6 of the tribe Trematocarini. The excess of nonsynonymous substitutions in these examples were indicated as dN/dS > 1, which were all statistically significant by Fisher’s exact test. Furthermore, we speculate that the amino acid changes in these episodic events are likely functional switch because they occurred in the putative ligand-binding pocket. Our finding of the occurrence of multiple episodic events and the unexpected gene diversity in one unique gene family is suggestive of the contribution of the V1R to the species diversification and the social interaction in cichlids.
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Affiliation(s)
- Masato Nikaido
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Tomoki Ota
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Tadashi Hirata
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hikoyu Suzuki
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yoko Satta
- Department of Biosystems Science, School of Advanced Sciences, The Graduate University for Advanced Studies (Sokendai), Hayama, Japan
| | - Mitsuto Aibara
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, JapanFoundation for Advancement of International Science, Tsukuba, Japan
| | - Semvua I Mzighani
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, JapanTanzania Fisheries Research Institute, Dar es Salaam, Tanzania
| | | | - Kimiko Hagino-Yamagishi
- Department of Dementia and Higher Brain Function, Integrated Neuroscience Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Norihiro Okada
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, JapanFoundation for Advancement of International Science, Tsukuba, JapanDepartment of Life Sciences, National Cheng Kung University, Tainan, Taiwan
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15
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Dawson HD, Loveland JE, Pascal G, Gilbert JGR, Uenishi H, Mann KM, Sang Y, Zhang J, Carvalho-Silva D, Hunt T, Hardy M, Hu Z, Zhao SH, Anselmo A, Shinkai H, Chen C, Badaoui B, Berman D, Amid C, Kay M, Lloyd D, Snow C, Morozumi T, Cheng RPY, Bystrom M, Kapetanovic R, Schwartz JC, Kataria R, Astley M, Fritz E, Steward C, Thomas M, Wilming L, Toki D, Archibald AL, Bed’Hom B, Beraldi D, Huang TH, Ait-Ali T, Blecha F, Botti S, Freeman TC, Giuffra E, Hume DA, Lunney JK, Murtaugh MP, Reecy JM, Harrow JL, Rogel-Gaillard C, Tuggle CK. Structural and functional annotation of the porcine immunome. BMC Genomics 2013; 14:332. [PMID: 23676093 PMCID: PMC3658956 DOI: 10.1186/1471-2164-14-332] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/03/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The domestic pig is known as an excellent model for human immunology and the two species share many pathogens. Susceptibility to infectious disease is one of the major constraints on swine performance, yet the structure and function of genes comprising the pig immunome are not well-characterized. The completion of the pig genome provides the opportunity to annotate the pig immunome, and compare and contrast pig and human immune systems. RESULTS The Immune Response Annotation Group (IRAG) used computational curation and manual annotation of the swine genome assembly 10.2 (Sscrofa10.2) to refine the currently available automated annotation of 1,369 immunity-related genes through sequence-based comparison to genes in other species. Within these genes, we annotated 3,472 transcripts. Annotation provided evidence for gene expansions in several immune response families, and identified artiodactyl-specific expansions in the cathelicidin and type 1 Interferon families. We found gene duplications for 18 genes, including 13 immune response genes and five non-immune response genes discovered in the annotation process. Manual annotation provided evidence for many new alternative splice variants and 8 gene duplications. Over 1,100 transcripts without porcine sequence evidence were detected using cross-species annotation. We used a functional approach to discover and accurately annotate porcine immune response genes. A co-expression clustering analysis of transcriptomic data from selected experimental infections or immune stimulations of blood, macrophages or lymph nodes identified a large cluster of genes that exhibited a correlated positive response upon infection across multiple pathogens or immune stimuli. Interestingly, this gene cluster (cluster 4) is enriched for known general human immune response genes, yet contains many un-annotated porcine genes. A phylogenetic analysis of the encoded proteins of cluster 4 genes showed that 15% exhibited an accelerated evolution as compared to 4.1% across the entire genome. CONCLUSIONS This extensive annotation dramatically extends the genome-based knowledge of the molecular genetics and structure of a major portion of the porcine immunome. Our complementary functional approach using co-expression during immune response has provided new putative immune response annotation for over 500 porcine genes. Our phylogenetic analysis of this core immunome cluster confirms rapid evolutionary change in this set of genes, and that, as in other species, such genes are important components of the pig's adaptation to pathogen challenge over evolutionary time. These comprehensive and integrated analyses increase the value of the porcine genome sequence and provide important tools for global analyses and data-mining of the porcine immune response.
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Affiliation(s)
- Harry D Dawson
- USDA-ARS, Beltsville Human Nutrition Research Center, Diet, Genomics, and Immunology Laboratory, Beltsville, MD 20705, USA
| | - Jane E Loveland
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Géraldine Pascal
- INRA, UMR85 Physiologie de la Reproduction et des Comportements, F-37380, Nouzilly, France
| | - James GR Gilbert
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Hirohide Uenishi
- National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Katherine M Mann
- USDA ARS BA Animal Parasitic Diseases Laboratory, Beltsville, MD 20705, USA
| | - Yongming Sang
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Jie Zhang
- Laboratory of Animal Genetics, Breeding, and Reproduction, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Denise Carvalho-Silva
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK,Current affiliation: EMBL Outstation-Hinxton, European Bioinformatics Institute, Wellcome Trust Genome Campus, Cambs CB10 1SD, UK
| | - Toby Hunt
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Matthew Hardy
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Zhiliang Hu
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Shu-Hong Zhao
- Laboratory of Animal Genetics, Breeding, and Reproduction, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Anna Anselmo
- Parco Tecnologico Padano, Integrative Biology Unit, via A. Einstein, 26900, Lodi, Italy
| | - Hiroki Shinkai
- National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Celine Chen
- USDA-ARS, Beltsville Human Nutrition Research Center, Diet, Genomics, and Immunology Laboratory, Beltsville, MD 20705, USA
| | - Bouabid Badaoui
- Parco Tecnologico Padano, Integrative Biology Unit, via A. Einstein, 26900, Lodi, Italy
| | - Daniel Berman
- USDA ARS BA Animal Parasitic Diseases Laboratory, Beltsville, MD 20705, USA
| | - Clara Amid
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK,Current affiliation: EMBL Outstation-Hinxton, European Bioinformatics Institute, Wellcome Trust Genome Campus, Cambs CB10 1SD, UK
| | - Mike Kay
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - David Lloyd
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Catherine Snow
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Takeya Morozumi
- Institute of Japan Association for Technology in Agriculture, Forestry and Fisheries, 446-1 Ippaizuka, Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan
| | - Ryan Pei-Yen Cheng
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Megan Bystrom
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Ronan Kapetanovic
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - John C Schwartz
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA
| | - Ranjit Kataria
- National Bureau of Animal Genetic Resources, P.B. 129, GT Road By-Pass, Karnal 132001, (Haryana), India
| | - Matthew Astley
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Eric Fritz
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Charles Steward
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Mark Thomas
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Laurens Wilming
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Daisuke Toki
- Institute of Japan Association for Technology in Agriculture, Forestry and Fisheries, 446-1 Ippaizuka, Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan
| | - Alan L Archibald
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Bertrand Bed’Hom
- INRA, UMR1313 Génétique Animale et Biologie Intégrative, F-78350, Jouy-en-Josas, France
| | - Dario Beraldi
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Ting-Hua Huang
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Tahar Ait-Ali
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Frank Blecha
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
| | - Sara Botti
- Parco Tecnologico Padano, Integrative Biology Unit, via A. Einstein, 26900, Lodi, Italy
| | - Tom C Freeman
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Elisabetta Giuffra
- Parco Tecnologico Padano, Integrative Biology Unit, via A. Einstein, 26900, Lodi, Italy,INRA, UMR1313 Génétique Animale et Biologie Intégrative, F-78350, Jouy-en-Josas, France
| | - David A Hume
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Joan K Lunney
- USDA ARS BA Animal Parasitic Diseases Laboratory, Beltsville, MD 20705, USA
| | - Michael P Murtaugh
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA
| | - James M Reecy
- Department of Animal Science, Iowa State University, Ames, IA 50011, USA
| | - Jennifer L Harrow
- Informatics Department, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambs CB10 1SA, UK
| | - Claire Rogel-Gaillard
- INRA, UMR1313 Génétique Animale et Biologie Intégrative, F-78350, Jouy-en-Josas, France
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Arambula D, Wong W, Medhekar BA, Guo H, Gingery M, Czornyj E, Liu M, Dey S, Ghosh P, Miller JF. Surface display of a massively variable lipoprotein by a Legionella diversity-generating retroelement. Proc Natl Acad Sci U S A 2013; 110:8212-7. [PMID: 23633572 DOI: 10.1073/pnas.1301366110] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Diversity-generating retroelements (DGRs) are a unique family of retroelements that confer selective advantages to their hosts by facilitating localized DNA sequence evolution through a specialized error-prone reverse transcription process. We characterized a DGR in Legionella pneumophila, an opportunistic human pathogen that causes Legionnaires disease. The L. pneumophila DGR is found within a horizontally acquired genomic island, and it can theoretically generate 10(26) unique nucleotide sequences in its target gene, legionella determinent target A (ldtA), creating a repertoire of 10(19) distinct proteins. Expression of the L. pneumophila DGR resulted in transfer of DNA sequence information from a template repeat to a variable repeat (VR) accompanied by adenine-specific mutagenesis of progeny VRs at the 3'end of ldtA. ldtA encodes a twin-arginine translocated lipoprotein that is anchored in the outer leaflet of the outer membrane, with its C-terminal variable region surface exposed. Related DGRs were identified in L. pneumophila clinical isolates that encode unique target proteins with homologous VRs, demonstrating the adaptability of DGR components. This work characterizes a DGR that diversifies a bacterial protein and confirms the hypothesis that DGR-mediated mutagenic homing occurs through a conserved mechanism. Comparative bioinformatics predicts that surface display of massively variable proteins is a defining feature of a subset of bacterial DGRs.
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Olivera BM, Watkins M, Bandyopadhyay P, Imperial JS, de la Cotera EPH, Aguilar MB, Vera EL, Concepcion GP, Lluisma A. Adaptive radiation of venomous marine snail lineages and the accelerated evolution of venom peptide genes. Ann N Y Acad Sci 2012; 1267:61-70. [PMID: 22954218 PMCID: PMC3488454 DOI: 10.1111/j.1749-6632.2012.06603.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
An impressive biodiversity (>10,000 species) of marine snails (suborder Toxoglossa or superfamily Conoidea) have complex venoms, each containing approximately 100 biologically active, disulfide-rich peptides. In the genus Conus, the most intensively investigated toxoglossan lineage (∼500 species), a small set of venom gene superfamilies undergo rapid sequence hyperdiversification within their mature toxin regions. Each major lineage of Toxoglossa has its own distinct set of venom gene superfamilies. Two recently identified venom gene superfamilies are expressed in the large Turridae clade, but not in Conus. Thus, as major venomous molluscan clades expand, a small set of lineage-specific venom gene superfamilies undergo accelerated evolution. The juxtaposition of extremely conserved signal sequences with hypervariable mature peptide regions is unprecedented and raises the possibility that in these gene superfamilies, the signal sequences are conserved as a result of an essential role they play in enabling rapid sequence evolution of the region of the gene that encodes the active toxin.
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18
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Abstract
Olfactory receptor (OR) is a large family of G protein–coupled receptors that can detect odorant in order to generate the sense of smell. They constitute one of the largest multiple gene families in animals including primates. To better understand the variation in odor perception and evolution of OR genes among primates, we computationally identified OR gene repertoires in orangutans, marmosets, and mouse lemurs and investigated the birth-and-death process of OR genes in the primate lineage. The results showed that 1) all the primate species studied have no more than 400 intact OR genes, fewer than rodents and canine; 2) Despite the similar number of OR genes in the genome, the makeup of the OR gene repertoires between different primate species is quite different as they had undergone dramatic birth-and-death evolution with extensive gene losses in the lineages leading to current species; 3) Apes and Old World monkey (OWM) have similar fraction of pseudogenes, whereas New World monkey (NWM) have fewer pseudogenes. To measure the selective pressure that had affected the OR gene repertoires in primates, we compared the ratio of nonsynonymous with synonymous substitution rates by using 70 one-to-one orthologous quintets among five primate species. We found that OR genes showed relaxed selective constraints in apes (humans, chimpanzees, and orangutans) than in OWMs (macaques) and NWMs (marmosets). We concluded that OR gene repertoires in primates have evolved in such a way to adapt to their respective living environments. Differential selective constraints might play important role in the primate OR gene evolution in each primate species.
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Affiliation(s)
- Dong Dong
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
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