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Hara Y, Kuraku S. Intragenomic mutational heterogeneity: structural and functional insights from gene evolution. Trends Genet 2025:S0168-9525(25)00075-7. [PMID: 40328580 DOI: 10.1016/j.tig.2025.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2025] [Revised: 03/27/2025] [Accepted: 03/28/2025] [Indexed: 05/08/2025]
Abstract
Variation of mutation rates between species has been documented over decades, but the variation between different regions of a genome has been less often discussed. Recent studies using high-quality sequence data have revealed previously unknown levels of intragenomic heterogeneity of mutation rates and their association with other structural and functional features of DNA sequences. This article reviews accumulating evidence of this intragenomic heterogeneity and speculates its cause and influence on organismal phenotypes.
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Affiliation(s)
- Yuichiro Hara
- Department of Data Science, Kitasato University School of Frontier Engineering, Sagamihara, Japan; Research Center for Genome & Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Shigehiro Kuraku
- Molecular Life History Laboratory, National Institute of Genetics, Mishima, Japan; Department of Genetics, SOKENDAI (Graduate University for Advanced Studies), Mishima, Japan.
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2
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James JE, Lascoux M. Amino Acid Properties, Substitution Rates, and the Nearly Neutral Theory. Genome Biol Evol 2025; 17:evaf025. [PMID: 39971341 PMCID: PMC11884779 DOI: 10.1093/gbe/evaf025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2024] [Revised: 02/05/2025] [Accepted: 02/12/2025] [Indexed: 02/21/2025] Open
Abstract
Do the properties of amino acids affect their rates of substitution? The neutral theory predicts that greater selective constraint leads to slower rates of evolution; similarly, we expect amino acids that are more different from each other to have lower rates of exchange because such changes are most likely to affect protein structure and function. Here, we test these predictions, using substitution rates estimated from empirical amino acid exchangeability matrices. To measure degree of amino acid difference, we focused on two physicochemical properties, charge and size, uncorrelated metrics that are known to have important implications for protein structure and function. We find that for both charge and size, amino acid pairs with large differences had lower rates of substitution. We also found that amino acids that differed in both properties had the lowest rates of substitution, suggesting that both physicochemical properties are under selective constraint. Mutation properties, such as the number of mutations or the number of transitions as opposed to transversions separating amino acid pairs, were also important predictors of substitution rates. The relationship between amino acid substitution rates and differences in their physiochemical properties holds across several taxonomically restricted datasets. This finding suggests that purifying selection affects amino acid substitution rates in a similar manner across taxonomic groups with different effective population sizes.
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Affiliation(s)
- Jennifer E James
- Department of Cell and Molecular Biology, SciLifeLab, Uppsala University, Uppsala, Sweden
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Martin Lascoux
- Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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3
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Waneka G, Pate B, Monroe JG, Sloan DB. Exploring the Relationship Between Gene Expression and Low-Frequency Somatic Mutations in Arabidopsis with Duplex Sequencing. Genome Biol Evol 2024; 16:evae213. [PMID: 39365161 PMCID: PMC11489876 DOI: 10.1093/gbe/evae213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 09/07/2024] [Accepted: 09/10/2024] [Indexed: 10/05/2024] Open
Abstract
Intragenomic mutation rates can vary dramatically due to transcription-associated mutagenesis or transcription-coupled repair, which vary based on local epigenomic modifications that are nonuniformly distributed across genomes. One feature associated with decreased mutation is higher expression level, which depends on environmental cues. To understand the magnitude of expression-dependent mutation rate variation, we perturbed expression through a heat treatment in Arabidopsis thaliana. We quantified gene expression to identify differentially expressed genes, which we then targeted for mutation detection using duplex sequencing. This approach provided a highly accurate measurement of the frequency of rare somatic mutations in vegetative plant tissues, which has been a recent source of uncertainty. Somatic mutations in plants may be useful for understanding drivers of DNA damage and repair in the germline since plants experience late germline segregation and both somatic and germline cells share common repair machinery. We included mutant lines lacking mismatch repair (MMR) and base excision repair (BER) capabilities to understand how repair mechanisms may drive biased mutation accumulation. We found wild-type (WT) and BER mutant mutation frequencies to be very low (mean variant frequency 1.8 × 10-8 and 2.6 × 10-8, respectively), while MMR mutant frequencies were significantly elevated (1.13 × 10-6). Interestingly, in the MMR mutant lines, there was no difference in the somatic mutation frequencies between temperature treatments or between highly versus lowly expressed genes. The extremely low somatic variant frequencies in WT plants indicate that larger datasets will be needed to address fundamental evolutionary questions about whether environmental change leads to gene-specific changes in mutation rate.
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Affiliation(s)
- Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Braden Pate
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - J Grey Monroe
- Department of Plant Sciences, University of California, Davis, Davis, CA, USA
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO, USA
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4
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Liang X, Yang S, Wang D, Knief U. Characterization and distribution of de novo mutations in the zebra finch. Commun Biol 2024; 7:1243. [PMID: 39358581 PMCID: PMC11447093 DOI: 10.1038/s42003-024-06945-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 09/24/2024] [Indexed: 10/04/2024] Open
Abstract
Germline de novo mutations (DNMs) provide the raw material for evolution. The DNM rate varies considerably between species, sexes and chromosomes. Here, we identify DNMs in the zebra finch (Taeniopygia guttata) across 16 parent-offspring trios using two genome assemblies of different quality. Using an independent genotyping assay, we validate 82% of the 150 candidate DNMs. DNM rates are consistent between both assemblies, with estimates of 6.14 × 10-9 and 6.36 × 10-9 per site per generation. We observe a strong paternal bias in DNM rates (male-to-female ratio ɑ ≈ 4), but this bias is in transition mutations only, leading to a transition-to-transversion ratio of 3.18 and 3.57. Finally, we find that DNMs tend to be randomly distributed across chromosomes, not associated with recombination hotspots or genic regions. However, the sex chromosome chrZ shows a roughly fourfold increased DNM rate compared to autosomes, which is more than the expected increase due to chrZ spending two-thirds of its time in males. Overall, our results further enhance our understanding of DNMs in passerine songbirds.
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Affiliation(s)
- Xixi Liang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shuai Yang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Daiping Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Ulrich Knief
- Evolutionary Biology & Ecology, Faculty of Biology, University of Freiburg, Freiburg, Germany
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5
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Polizzi B, Calvez V, Charlat S, Rajon E. (Epi)mutation Rates and the Evolution of Composite Trait Architectures. Am Nat 2024; 204:E42-E56. [PMID: 39179232 DOI: 10.1086/731461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2024]
Abstract
AbstractMutation rates vary widely along genomes and across inheritance systems. This suggests that complex traits-resulting from the contributions of multiple determinants-might be composite in terms of the underlying mutation rates. Here we investigate through mathematical modeling whether such a heterogeneity may drive changes in a trait's architecture, especially in fluctuating environments, where phenotypic instability can be beneficial. We first identify a convexity principle related to the shape of the trait's fitness function, setting conditions under which composite architectures should be adaptive or, conversely and more commonly, should be selected against. Simulations reveal, however, that applying this principle to realistic evolving populations requires taking into account pervasive epistatic interactions that take place in the system. Indeed, the fate of a mutation affecting the architecture depends on the (epi)genetic background, which itself depends on the current architecture in the population. We tackle this problem by borrowing the adaptive dynamics framework from evolutionary ecology-where it is routinely used to deal with such resident/mutant dependencies-and find that the principle excluding composite architectures generally prevails. Yet the predicted evolutionary trajectories will typically depend on the initial architecture, possibly resulting in historical contingencies. Finally, by relaxing the large population size assumption, we unexpectedly find that not only the strength of selection on a trait's architecture but also its direction depend on population size, revealing a new occurrence of the recently identified phenomenon coined "sign inversion."
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6
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Beichman AC, Zhu L, Harris K. The Evolutionary Interplay of Somatic and Germline Mutation Rates. Annu Rev Biomed Data Sci 2024; 7:83-105. [PMID: 38669515 DOI: 10.1146/annurev-biodatasci-102523-104225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024]
Abstract
Novel sequencing technologies are making it increasingly possible to measure the mutation rates of somatic cell lineages. Accurate germline mutation rate measurement technologies have also been available for a decade, making it possible to assess how this fundamental evolutionary parameter varies across the tree of life. Here, we review some classical theories about germline and somatic mutation rate evolution that were formulated using principles of population genetics and the biology of aging and cancer. We find that somatic mutation rate measurements, while still limited in phylogenetic diversity, seem consistent with the theory that selection to preserve the soma is proportional to life span. However, germline and somatic theories make conflicting predictions regarding which species should have the most accurate DNA repair. Resolving this conflict will require carefully measuring how mutation rates scale with time and cell division and achieving a better understanding of mutation rate pleiotropy among cell types.
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Affiliation(s)
- Annabel C Beichman
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA;
| | - Luke Zhu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Kelley Harris
- Computational Biology Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA;
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7
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Wu K, Qin D, Qian Y, Liu H. A new era of mutation rate analyses: Concepts and methods. Zool Res 2024; 45:767-780. [PMID: 38894520 PMCID: PMC11298668 DOI: 10.24272/j.issn.2095-8137.2024.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
The mutation rate is a pivotal biological characteristic, intricately governed by natural selection and historically garnering considerable attention. Recent advances in high-throughput sequencing and analytical methodologies have profoundly transformed our understanding in this domain, ushering in an unprecedented era of mutation rate research. This paper aims to provide a comprehensive overview of the key concepts and methodologies frequently employed in the study of mutation rates. It examines various types of mutations, explores the evolutionary dynamics and associated theories, and synthesizes both classical and contemporary hypotheses. Furthermore, this review comprehensively explores recent advances in understanding germline and somatic mutations in animals and offers an overview of experimental methodologies, mutational patterns, molecular mechanisms, and driving forces influencing variations in mutation rates across species and tissues. Finally, it proposes several potential research directions and pressing questions for future investigations.
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Affiliation(s)
- Kun Wu
- Center for Evolutionary & Organismal Biology and the Fourth Affiliated Hospital of Zhejiang University, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Danqi Qin
- Center for Evolutionary & Organismal Biology and the Fourth Affiliated Hospital of Zhejiang University, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yang Qian
- Center for Evolutionary & Organismal Biology and the Fourth Affiliated Hospital of Zhejiang University, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Haoxuan Liu
- Center for Evolutionary & Organismal Biology and the Fourth Affiliated Hospital of Zhejiang University, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China. E-mail:
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Baduel P, Sammarco I, Barrett R, Coronado‐Zamora M, Crespel A, Díez‐Rodríguez B, Fox J, Galanti D, González J, Jueterbock A, Wootton E, Harney E. The evolutionary consequences of interactions between the epigenome, the genome and the environment. Evol Appl 2024; 17:e13730. [PMID: 39050763 PMCID: PMC11266121 DOI: 10.1111/eva.13730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/30/2024] [Accepted: 05/22/2024] [Indexed: 07/27/2024] Open
Abstract
The epigenome is the suite of interacting chemical marks and molecules that helps to shape patterns of development, phenotypic plasticity and gene regulation, in part due to its responsiveness to environmental stimuli. There is increasing interest in understanding the functional and evolutionary importance of this sensitivity under ecologically realistic conditions. Observations that epigenetic variation abounds in natural populations have prompted speculation that it may facilitate evolutionary responses to rapid environmental perturbations, such as those occurring under climate change. A frequent point of contention is whether epigenetic variants reflect genetic variation or are independent of it. The genome and epigenome often appear tightly linked and interdependent. While many epigenetic changes are genetically determined, the converse is also true, with DNA sequence changes influenced by the presence of epigenetic marks. Understanding how the epigenome, genome and environment interact with one another is therefore an essential step in explaining the broader evolutionary consequences of epigenomic variation. Drawing on results from experimental and comparative studies carried out in diverse plant and animal species, we synthesize our current understanding of how these factors interact to shape phenotypic variation in natural populations, with a focus on identifying similarities and differences between taxonomic groups. We describe the main components of the epigenome and how they vary within and between taxa. We review how variation in the epigenome interacts with genetic features and environmental determinants, with a focus on the role of transposable elements (TEs) in integrating the epigenome, genome and environment. And we look at recent studies investigating the functional and evolutionary consequences of these interactions. Although epigenetic differentiation in nature is likely often a result of drift or selection on stochastic epimutations, there is growing evidence that a significant fraction of it can be stably inherited and could therefore contribute to evolution independently of genetic change.
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Affiliation(s)
- Pierre Baduel
- Institut de Biologie de l'Ecole Normale SupérieurePSL University, CNRSParisFrance
| | - Iris Sammarco
- Institute of Botany of the Czech Academy of SciencesPrůhoniceCzechia
| | - Rowan Barrett
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | | | | | | | - Janay Fox
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Dario Galanti
- Institute of Evolution and Ecology (EvE)University of TuebingenTübingenGermany
| | | | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and AquacultureNord UniversityBodøNorway
| | - Eric Wootton
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Ewan Harney
- Institute of Evolutionary BiologyCSIC, UPFBarcelonaSpain
- School of BiosciencesUniversity of SheffieldSheffieldUK
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9
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Quiroz D, Oya S, Lopez-Mateos D, Zhao K, Pierce A, Ortega L, Ali A, Carbonell-Bejerano P, Yarov-Yarovoy V, Suzuki S, Hayashi G, Osakabe A, Monroe G. H3K4me1 recruits DNA repair proteins in plants. THE PLANT CELL 2024; 36:2410-2426. [PMID: 38531669 PMCID: PMC11132887 DOI: 10.1093/plcell/koae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/28/2024]
Abstract
DNA repair proteins can be recruited by their histone reader domains to specific epigenomic features, with consequences on intragenomic mutation rate variation. Here, we investigated H3K4me1-associated hypomutation in plants. We first examined 2 proteins which, in plants, contain Tudor histone reader domains: PRECOCIOUS DISSOCIATION OF SISTERS 5 (PDS5C), involved in homology-directed repair, and MUTS HOMOLOG 6 (MSH6), a mismatch repair protein. The MSH6 Tudor domain of Arabidopsis (Arabidopsis thaliana) binds to H3K4me1 as previously demonstrated for PDS5C, which localizes to H3K4me1-rich gene bodies and essential genes. Mutations revealed by ultradeep sequencing of wild-type and msh6 knockout lines in Arabidopsis show that functional MSH6 is critical for the reduced rate of single-base substitution (SBS) mutations in gene bodies and H3K4me1-rich regions. We explored the breadth of these mechanisms among plants by examining a large rice (Oryza sativa) mutation data set. H3K4me1-associated hypomutation is conserved in rice as are the H3K4me1-binding residues of MSH6 and PDS5C Tudor domains. Recruitment of DNA repair proteins by H3K4me1 in plants reveals convergent, but distinct, epigenome-recruited DNA repair mechanisms from those well described in humans. The emergent model of H3K4me1-recruited repair in plants is consistent with evolutionary theory regarding mutation modifier systems and offers mechanistic insight into intragenomic mutation rate variation in plants.
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Affiliation(s)
- Daniela Quiroz
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
- Integrative Genetics and Genomics, University of California Davis, Davis, CA 95616, USA
| | - Satoyo Oya
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
- Laboratory of Genetics, Department of Biological Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Diego Lopez-Mateos
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
- Biophysics Graduate Group, University of California Davis, Davis, CA 95616, USA
| | - Kehan Zhao
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
- Plant Biology Graduate Group, University of California Davis, Davis, CA 95616, USA
| | - Alice Pierce
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
- Plant Biology Graduate Group, University of California Davis, Davis, CA 95616, USA
| | - Lissandro Ortega
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
| | - Alissza Ali
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
| | | | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
- Biophysics Graduate Group, University of California Davis, Davis, CA 95616, USA
| | - Sae Suzuki
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya 464-0814, Japan
| | - Gosuke Hayashi
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya 464-0814, Japan
| | - Akihisa Osakabe
- Laboratory of Genetics, Department of Biological Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Grey Monroe
- Department of Plant Sciences, University of California Davis, Davis, CA 95616, USA
- Integrative Genetics and Genomics, University of California Davis, Davis, CA 95616, USA
- Plant Biology Graduate Group, University of California Davis, Davis, CA 95616, USA
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10
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Waneka G, Pate B, Monroe JG, Sloan DB. Investigating low frequency somatic mutations in Arabidopsis with Duplex Sequencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.31.578196. [PMID: 38352550 PMCID: PMC10862904 DOI: 10.1101/2024.01.31.578196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Mutations are the source of novel genetic diversity but can also lead to disease and maladaptation. The conventional view is that mutations occur randomly with respect to their environment-specific fitness consequences. However, intragenomic mutation rates can vary dramatically due to transcription coupled repair and based on local epigenomic modifications, which are non-uniformly distributed across genomes. One sequence feature associated with decreased mutation is higher expression level, which can vary depending on environmental cues. To understand whether the association between expression level and mutation rate creates a systematic relationship with environment-specific fitness effects, we perturbed expression through a heat treatment in Arabidopsis thaliana. We quantified gene expression to identify differentially expressed genes, which we then targeted for mutation detection using Duplex Sequencing. This approach provided a highly accurate measurement of the frequency of rare somatic mutations in vegetative plant tissues, which has been a recent source of uncertainty in plant mutation research. We included mutant lines lacking mismatch repair (MMR) and base excision repair (BER) capabilities to understand how repair mechanisms may drive biased mutation accumulation. We found wild type (WT) and BER mutant mutation frequencies to be very low (mean variant frequency 1.8×10-8 and 2.6×10-8, respectively), while MMR mutant frequencies were significantly elevated (1.13×10-6). These results show that somatic variant frequencies are extremely low in WT plants, indicating that larger datasets will be needed to address the fundamental evolutionary question as to whether environmental change leads to gene-specific changes in mutation rate.
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Affiliation(s)
- Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Braden Pate
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - J Grey Monroe
- Department of Plant Sciences, University of California, Davis, Davis, CA USA
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
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11
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Livnat A, Love AC. Mutation and evolution: Conceptual possibilities. Bioessays 2024; 46:e2300025. [PMID: 38254311 DOI: 10.1002/bies.202300025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 01/24/2024]
Abstract
Although random mutation is central to models of evolutionary change, a lack of clarity remains regarding the conceptual possibilities for thinking about the nature and role of mutation in evolution. We distinguish several claims at the intersection of mutation, evolution, and directionality and then characterize a previously unrecognized category: complex conditioned mutation. Empirical evidence in support of this category suggests that the historically famous fluctuation test should be revisited, and new experiments should be undertaken with emerging experimental techniques to facilitate detecting mutation rates within specific loci at an ultra-high, individual base pair resolution.
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Affiliation(s)
- Adi Livnat
- Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Alan C Love
- Department of Philosophy and Minnesota Center for Philosophy of Science, University of Minnesota (Twin Cities), Minneapolis, Minnesota, USA
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12
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Horton JS, Taylor TB. Mutation bias and adaptation in bacteria. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001404. [PMID: 37943288 PMCID: PMC10710837 DOI: 10.1099/mic.0.001404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 10/11/2023] [Indexed: 11/10/2023]
Abstract
Genetic mutation, which provides the raw material for evolutionary adaptation, is largely a stochastic force. However, there is ample evidence showing that mutations can also exhibit strong biases, with some mutation types and certain genomic positions mutating more often than others. It is becoming increasingly clear that mutational bias can play a role in determining adaptive outcomes in bacteria in both the laboratory and the clinic. As such, understanding the causes and consequences of mutation bias can help microbiologists to anticipate and predict adaptive outcomes. In this review, we provide an overview of the mechanisms and features of the bacterial genome that cause mutational biases to occur. We then describe the environmental triggers that drive these mechanisms to be more potent and outline the adaptive scenarios where mutation bias can synergize with natural selection to define evolutionary outcomes. We conclude by describing how understanding mutagenic genomic features can help microbiologists predict areas sensitive to mutational bias, and finish by outlining future work that will help us achieve more accurate evolutionary forecasts.
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Affiliation(s)
- James S. Horton
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, BA2 7AY, UK
| | - Tiffany B. Taylor
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, BA2 7AY, UK
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13
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Lynch M, Ali F, Lin T, Wang Y, Ni J, Long H. The divergence of mutation rates and spectra across the Tree of Life. EMBO Rep 2023; 24:e57561. [PMID: 37615267 PMCID: PMC10561183 DOI: 10.15252/embr.202357561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/25/2023] Open
Abstract
Owing to advances in genome sequencing, genome stability has become one of the most scrutinized cellular traits across the Tree of Life. Despite its centrality to all things biological, the mutation rate (per nucleotide site per generation) ranges over three orders of magnitude among species and several-fold within individual phylogenetic lineages. Within all major organismal groups, mutation rates scale negatively with the effective population size of a species and with the amount of functional DNA in the genome. This relationship is most parsimoniously explained by the drift-barrier hypothesis, which postulates that natural selection typically operates to reduce mutation rates until further improvement is thwarted by the power of random genetic drift. Despite this constraint, the molecular mechanisms underlying DNA replication fidelity and repair are free to wander, provided the performance of the entire system is maintained at the prevailing level. The evolutionary flexibility of the mutation rate bears on the resolution of several prior conundrums in phylogenetic and population-genetic analysis and raises challenges for future applications in these areas.
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Affiliation(s)
- Michael Lynch
- Biodesign Center for Mechanisms of EvolutionArizona State UniversityTempeAZUSA
| | - Farhan Ali
- Biodesign Center for Mechanisms of EvolutionArizona State UniversityTempeAZUSA
| | - Tongtong Lin
- Institute of Evolution and Marine Biodiversity, KLMMEOcean University of ChinaQingdaoChina
| | - Yaohai Wang
- Institute of Evolution and Marine Biodiversity, KLMMEOcean University of ChinaQingdaoChina
| | - Jiahao Ni
- Institute of Evolution and Marine Biodiversity, KLMMEOcean University of ChinaQingdaoChina
| | - Hongan Long
- Institute of Evolution and Marine Biodiversity, KLMMEOcean University of ChinaQingdaoChina
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14
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Staunton PM, Peters AJ, Seoighe C. Somatic mutations inferred from RNA-seq data highlight the contribution of replication timing to mutation rate variation in a model plant. Genetics 2023; 225:iyad128. [PMID: 37450609 PMCID: PMC10550316 DOI: 10.1093/genetics/iyad128] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 03/23/2023] [Accepted: 06/11/2023] [Indexed: 07/18/2023] Open
Abstract
Variation in the rates and characteristics of germline and somatic mutations across the genome of an organism is informative about DNA damage and repair processes and can also shed light on aspects of organism physiology and evolution. We adapted a recently developed method for inferring somatic mutations from bulk RNA-seq data and applied it to a large collection of Arabidopsis thaliana accessions. The wide range of genomic data types available for A. thaliana enabled us to investigate the relationships of multiple genomic features with the variation in the somatic mutation rate across the genome of this model plant. We observed that late replicated regions showed evidence of an elevated rate of somatic mutation compared to genomic regions that are replicated early. We identified transcriptional strand asymmetries, consistent with the effects of transcription-coupled damage and/or repair. We also observed a negative relationship between the inferred somatic mutation count and the H3K36me3 histone mark which is well documented in the literature of human systems. In addition, we were able to support previous reports of an inverse relationship between inferred somatic mutation count and guanine-cytosine content as well as a positive relationship between inferred somatic mutation count and DNA methylation for both cytosine and noncytosine mutations.
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Affiliation(s)
- Patrick M Staunton
- School of Mathematical and Statistical Sciences, University of Galway, Galway H91 TK33, Ireland
| | - Andrew J Peters
- School of Mathematical and Statistical Sciences, University of Galway, Galway H91 TK33, Ireland
| | - Cathal Seoighe
- School of Mathematical and Statistical Sciences, University of Galway, Galway H91 TK33, Ireland
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15
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Majic P, Payne JL. Developmental Selection and the Perception of Mutation Bias. Mol Biol Evol 2023; 40:msad179. [PMID: 37556606 PMCID: PMC10443735 DOI: 10.1093/molbev/msad179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/22/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023] Open
Abstract
The notion that mutations are random relative to their fitness effects is central to the Neo-Darwinian view of evolution. However, a recent interpretation of the patterns of mutation accumulation in the genome of Arabidopsis thaliana has challenged this notion, arguing for the presence of a targeted DNA repair mechanism that causes a nonrandom association of mutation rates and fitness effects. Specifically, this mechanism was suggested to cause a reduction in the rates of mutations on essential genes, thus lowering the rates of deleterious mutations. Central to this argument were attempts to rule out selection at the population level. Here, we offer an alternative and parsimonious interpretation of the patterns of mutation accumulation previously attributed to mutation bias, showing how they can instead or additionally be caused by developmental selection, that is selection occurring at the cellular level during the development of a multicellular organism. Thus, the depletion of deleterious mutations in A. thaliana may indeed be the result of a selective process, rather than a bias in mutation. More broadly, our work highlights the importance of considering development in the interpretation of population-genetic analyses of multicellular organisms, and it emphasizes that efforts to identify mechanisms involved in mutational biases should explicitly account for developmental selection.
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Affiliation(s)
- Paco Majic
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Joshua L Payne
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
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16
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Monroe JG, Murray KD, Xian W, Srikant T, Carbonell-Bejerano P, Becker C, Lensink M, Exposito-Alonso M, Klein M, Hildebrandt J, Neumann M, Kliebenstein D, Weng ML, Imbert E, Ågren J, Rutter MT, Fenster CB, Weigel D. Reply to: Re-evaluating evidence for adaptive mutation rate variation. Nature 2023; 619:E57-E60. [PMID: 37495874 PMCID: PMC10371858 DOI: 10.1038/s41586-023-06315-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Affiliation(s)
| | - Kevin D Murray
- Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Wenfei Xian
- Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Thanvi Srikant
- Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | | | - Claude Becker
- Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | | | - Moises Exposito-Alonso
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Marie Klein
- University of California Davis, Davis, CA, USA
| | | | - Manuela Neumann
- Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | | | - Mao-Lun Weng
- Department of Biology, Westfield State University, Westfield, MA, USA
| | - Eric Imbert
- ISEM, University of Montpellier, Montpellier, France
| | - Jon Ågren
- Department of Ecology and Genetics, EBC, Uppsala University, Uppsala, Sweden
| | - Matthew T Rutter
- Department of Biology, College of Charleston, Charleston, SC, USA
| | - Charles B Fenster
- Oak Lake Field Station, South Dakota State University, Brookings, SD, USA
| | - Detlef Weigel
- Max Planck Institute for Biology Tübingen, Tübingen, Germany.
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17
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Charlesworth B, Jensen JD. Population Genetic Considerations Regarding Evidence for Biased Mutation Rates in Arabidopsis thaliana. Mol Biol Evol 2023; 40:msac275. [PMID: 36572441 PMCID: PMC9907473 DOI: 10.1093/molbev/msac275] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
It has recently been proposed that lower mutation rates in gene bodies compared with upstream and downstream sequences in Arabidopsis thaliana are the result of an "adaptive" modification of the rate of beneficial and deleterious mutations in these functional regions. This claim was based both on analyses of mutation accumulation lines and on population genomics data. Here, we show that several questionable assumptions were used in the population genomics analyses. In particular, we demonstrate that the difference between gene bodies and less selectively constrained sequences in the magnitude of Tajima's D can in principle be explained by the presence of sites subject to purifying selection and does not require lower mutation rates in regions experiencing selective constraints.
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Affiliation(s)
- Brian Charlesworth
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH8 9PU, United Kingdom
| | - Jeffrey D Jensen
- School of Life Sciences, Arizona State University, Tempe, 85281 AZ
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18
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Zhang J. What Has Genomics Taught An Evolutionary Biologist? GENOMICS, PROTEOMICS & BIOINFORMATICS 2023; 21:1-12. [PMID: 36720382 PMCID: PMC10373158 DOI: 10.1016/j.gpb.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/06/2023] [Accepted: 01/19/2023] [Indexed: 01/30/2023]
Abstract
Genomics, an interdisciplinary field of biology on the structure, function, and evolution of genomes, has revolutionized many subdisciplines of life sciences, including my field of evolutionary biology, by supplying huge data, bringing high-throughput technologies, and offering a new approach to biology. In this review, I describe what I have learned from genomics and highlight the fundamental knowledge and mechanistic insights gained. I focus on three broad topics that are central to evolutionary biology and beyond-variation, interaction, and selection-and use primarily my own research and study subjects as examples. In the next decade or two, I expect that the most important contributions of genomics to evolutionary biology will be to provide genome sequences of nearly all known species on Earth, facilitate high-throughput phenotyping of natural variants and systematically constructed mutants for mapping genotype-phenotype-fitness landscapes, and assist the determination of causality in evolutionary processes using experimental evolution.
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Affiliation(s)
- Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
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