1
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Berdan EL, Barton NH, Butlin R, Charlesworth B, Faria R, Fragata I, Gilbert KJ, Jay P, Kapun M, Lotterhos KE, Mérot C, Durmaz Mitchell E, Pascual M, Peichel CL, Rafajlović M, Westram AM, Schaeffer SW, Johannesson K, Flatt T. How chromosomal inversions reorient the evolutionary process. J Evol Biol 2023; 36:1761-1782. [PMID: 37942504 DOI: 10.1111/jeb.14242] [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: 05/05/2023] [Revised: 09/13/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
Inversions are structural mutations that reverse the sequence of a chromosome segment and reduce the effective rate of recombination in the heterozygous state. They play a major role in adaptation, as well as in other evolutionary processes such as speciation. Although inversions have been studied since the 1920s, they remain difficult to investigate because the reduced recombination conferred by them strengthens the effects of drift and hitchhiking, which in turn can obscure signatures of selection. Nonetheless, numerous inversions have been found to be under selection. Given recent advances in population genetic theory and empirical study, here we review how different mechanisms of selection affect the evolution of inversions. A key difference between inversions and other mutations, such as single nucleotide variants, is that the fitness of an inversion may be affected by a larger number of frequently interacting processes. This considerably complicates the analysis of the causes underlying the evolution of inversions. We discuss the extent to which these mechanisms can be disentangled, and by which approach.
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Affiliation(s)
- Emma L Berdan
- Bioinformatics Core, Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Nicholas H Barton
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Roger Butlin
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- Ecology and Evolutionary Biology, School of Bioscience, The University of Sheffield, Sheffield, UK
| | - Brian Charlesworth
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Rui Faria
- CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Inês Fragata
- CHANGE - Global Change and Sustainability Institute/Animal Biology Department, cE3c - Center for Ecology, Evolution and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisbon, Portugal
| | | | - Paul Jay
- Center for GeoGenetics, University of Copenhagen, Copenhagen, Denmark
| | - Martin Kapun
- Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
- Central Research Laboratories, Natural History Museum of Vienna, Vienna, Austria
| | - Katie E Lotterhos
- Department of Marine and Environmental Sciences, Northeastern University, Boston, Massachusetts, USA
| | - Claire Mérot
- UMR 6553 Ecobio, Université de Rennes, OSUR, CNRS, Rennes, France
| | - Esra Durmaz Mitchell
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Functional Genomics & Metabolism Research Unit, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
| | - Marta Pascual
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Catherine L Peichel
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Marina Rafajlović
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
- Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
| | - Anja M Westram
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Stephen W Schaeffer
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Kerstin Johannesson
- Linnaeus Centre for Marine Evolutionary Biology, University of Gothenburg, Gothenburg, Sweden
- Tjärnö Marine Laboratory, Department of Marine Sciences, University of Gothenburg, Strömstad, Sweden
| | - Thomas Flatt
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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2
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Baumdicker F, Bisschop G, Goldstein D, Gower G, Ragsdale AP, Tsambos G, Zhu S, Eldon B, Ellerman EC, Galloway JG, Gladstein AL, Gorjanc G, Guo B, Jeffery B, Kretzschmar WW, Lohse K, Matschiner M, Nelson D, Pope NS, Quinto-Cortés CD, Rodrigues MF, Saunack K, Sellinger T, Thornton K, van Kemenade H, Wohns AW, Wong Y, Gravel S, Kern AD, Koskela J, Ralph PL, Kelleher J. Efficient ancestry and mutation simulation with msprime 1.0. Genetics 2021; 220:6460344. [PMID: 34897427 PMCID: PMC9176297 DOI: 10.1093/genetics/iyab229] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/03/2021] [Indexed: 11/13/2022] Open
Abstract
Stochastic simulation is a key tool in population genetics, since the models involved are often analytically intractable and simulation is usually the only way of obtaining ground-truth data to evaluate inferences. Because of this, a large number of specialized simulation programs have been developed, each filling a particular niche, but with largely overlapping functionality and a substantial duplication of effort. Here, we introduce msprime version 1.0, which efficiently implements ancestry and mutation simulations based on the succinct tree sequence data structure and the tskit library. We summarize msprime’s many features, and show that its performance is excellent, often many times faster and more memory efficient than specialized alternatives. These high-performance features have been thoroughly tested and validated, and built using a collaborative, open source development model, which reduces duplication of effort and promotes software quality via community engagement.
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Affiliation(s)
- Franz Baumdicker
- Cluster of Excellence "Controlling Microbes to Fight Infections", Mathematical and Computational Population Genetics, University of Tübingen, 72076 Tübingen, Germany
| | - Gertjan Bisschop
- Institute of Evolutionary Biology,The University of Edinburgh, EH9 3FL, UK
| | - Daniel Goldstein
- Khoury College of Computer Sciences, Northeastern University, MA 02115, USA.,No affiliation
| | - Graham Gower
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Aaron P Ragsdale
- Department of Integrative Biology, University of Wisconsin-Madison, WI 53706, USA
| | - Georgia Tsambos
- Melbourne Integrative Genomics, School of Mathematics and Statistics, University of Melbourne, Victoria, 3010, Australia
| | - Sha Zhu
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF, UK
| | - Bjarki Eldon
- Leibniz Institute for Evolution and Biodiversity Science,Museum für Naturkunde Berlin, 10115, Germany
| | | | - Jared G Galloway
- Institute of Ecology and Evolution, Department of Biology, University of Oregon, OR 97403-5289, USA.,Computational Biology Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98102, USA
| | - Ariella L Gladstein
- Department of Genetics, University of North Carolina at Chapel Hill, NC 27599-7264, USA.,Embark Veterinary, Inc., Boston, MA 02111, USA
| | - Gregor Gorjanc
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, EH25 9RG, UK
| | - Bing Guo
- Institute for Genome Sciences,University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Ben Jeffery
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF, UK
| | - Warren W Kretzschmar
- Center for Hematology and Regenerative Medicine, Karolinska Institute, 141 83 Huddinge, Sweden
| | - Konrad Lohse
- Institute of Evolutionary Biology,The University of Edinburgh, EH9 3FL, UK
| | | | - Dominic Nelson
- Department of Human Genetics, McGill University, Montréal, QC H3A 0C7, Canada
| | - Nathaniel S Pope
- Department of Entomology, Pennsylvania State University, PA 16802, USA
| | - Consuelo D Quinto-Cortés
- National Laboratory of Genomics for Biodiversity (LANGEBIO), Unit of Advanced Genomics, CINVESTAV, Irapuato, Mexico
| | - Murillo F Rodrigues
- Institute of Ecology and Evolution, Department of Biology, University of Oregon, OR 97403-5289, USA
| | - Kumar Saunack
- IIT Bombay, Powai, Mumbai 400 076, Maharashtra, India
| | - Thibaut Sellinger
- Professorship for Population Genetics, Department of Life Science Systems, Technical University of Munich, 85354 Freising, Germany
| | - Kevin Thornton
- Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA
| | | | - Anthony W Wohns
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF, UK.,Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yan Wong
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF, UK
| | - Simon Gravel
- Department of Human Genetics, McGill University, Montréal, QC H3A 0C7, Canada
| | - Andrew D Kern
- Institute of Ecology and Evolution, Department of Biology, University of Oregon, OR 97403-5289, USA
| | - Jere Koskela
- Department of Statistics, University of Warwick, CV4 7AL, UK
| | - Peter L Ralph
- Institute of Ecology and Evolution, Department of Biology, University of Oregon, OR 97403-5289, USA.,Department of Mathematics, University of Oregon, OR 97403-5289 USA
| | - Jerome Kelleher
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, OX3 7LF, UK
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3
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Kapun M, Flatt T. The adaptive significance of chromosomal inversion polymorphisms inDrosophila melanogaster. Mol Ecol 2018; 28:1263-1282. [DOI: 10.1111/mec.14871] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/01/2018] [Accepted: 09/10/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Martin Kapun
- Department of BiologyUniversity of Fribourg Fribourg Switzerland
| | - Thomas Flatt
- Department of BiologyUniversity of Fribourg Fribourg Switzerland
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4
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Fuller ZL, Haynes GD, Richards S, Schaeffer SW. Genomics of natural populations: Evolutionary forces that establish and maintain gene arrangements inDrosophila pseudoobscura. Mol Ecol 2017; 26:6539-6562. [DOI: 10.1111/mec.14381] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/04/2017] [Accepted: 10/07/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Zachary L. Fuller
- Department of Biology; 208 Erwin W. Mueller Laboratory; The Pennsylvania State University; University Park PA USA
| | - Gwilym D. Haynes
- Department of Biology; 208 Erwin W. Mueller Laboratory; The Pennsylvania State University; University Park PA USA
| | - Stephen Richards
- Human Genome Sequencing Center; Baylor College of Medicine; Houston TX USA
| | - Stephen W. Schaeffer
- Department of Biology; 208 Erwin W. Mueller Laboratory; The Pennsylvania State University; University Park PA USA
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5
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Lindtke D, Lucek K, Soria-Carrasco V, Villoutreix R, Farkas TE, Riesch R, Dennis SR, Gompert Z, Nosil P. Long-term balancing selection on chromosomal variants associated with crypsis in a stick insect. Mol Ecol 2017; 26:6189-6205. [DOI: 10.1111/mec.14280] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 07/12/2017] [Accepted: 07/24/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Dorothea Lindtke
- Department of Biological Sciences; University of Calgary; Calgary AB Canada
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - Kay Lucek
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
- Department of Environmental Sciences; University of Basel; Basel Switzerland
| | | | - Romain Villoutreix
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - Timothy E. Farkas
- Department of Ecology and Evolutionary Biology; University of Connecticut; Storrs CT USA
| | - Rüdiger Riesch
- School of Biological Sciences; Royal Holloway; University of London; Egham UK
| | - Stuart R. Dennis
- Department of Aquatic Ecology; Eawag: Swiss Federal Institute of Aquatic Science and Technology; Dübendorf Switzerland
| | - Zach Gompert
- Department of Biology; Utah State University; Logan UT USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
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6
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Potter S, Bragg JG, Blom MPK, Deakin JE, Kirkpatrick M, Eldridge MDB, Moritz C. Chromosomal Speciation in the Genomics Era: Disentangling Phylogenetic Evolution of Rock-wallabies. Front Genet 2017; 8:10. [PMID: 28265284 PMCID: PMC5301020 DOI: 10.3389/fgene.2017.00010] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/18/2017] [Indexed: 12/24/2022] Open
Abstract
The association of chromosome rearrangements (CRs) with speciation is well established, and there is a long history of theory and evidence relating to "chromosomal speciation." Genomic sequencing has the potential to provide new insights into how reorganization of genome structure promotes divergence, and in model systems has demonstrated reduced gene flow in rearranged segments. However, there are limits to what we can understand from a small number of model systems, which each only tell us about one episode of chromosomal speciation. Progressing from patterns of association between chromosome (and genic) change, to understanding processes of speciation requires both comparative studies across diverse systems and integration of genome-scale sequence comparisons with other lines of evidence. Here, we showcase a promising example of chromosomal speciation in a non-model organism, the endemic Australian marsupial genus Petrogale. We present initial phylogenetic results from exon-capture that resolve a history of divergence associated with extensive and repeated CRs. Yet it remains challenging to disentangle gene tree heterogeneity caused by recent divergence and gene flow in this and other such recent radiations. We outline a way forward for better integration of comparative genomic sequence data with evidence from molecular cytogenetics, and analyses of shifts in the recombination landscape and potential disruption of meiotic segregation and epigenetic programming. In all likelihood, CRs impact multiple cellular processes and these effects need to be considered together, along with effects of genic divergence. Understanding the effects of CRs together with genic divergence will require development of more integrative theory and inference methods. Together, new data and analysis tools will combine to shed light on long standing questions of how chromosome and genic divergence promote speciation.
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Affiliation(s)
- Sally Potter
- Research School of Biology, Australian National University, ActonACT, Australia
- Australian Museum Research Institute, Australian Museum, SydneyNSW, Australia
| | - Jason G. Bragg
- National Herbarium of New South Wales, The Royal Botanic Gardens and Domain Trust, SydneyNSW, Australia
| | - Mozes P. K. Blom
- Department of Bioinformatics and Genetics, Swedish Museum of Natural HistoryStockholm, Sweden
| | - Janine E. Deakin
- Institute for Applied Ecology, University of Canberra, BruceACT, Australia
| | - Mark Kirkpatrick
- Department of Integrative Biology, University of Texas, AustinTX, USA
| | - Mark D. B. Eldridge
- Australian Museum Research Institute, Australian Museum, SydneyNSW, Australia
| | - Craig Moritz
- Research School of Biology, Australian National University, ActonACT, Australia
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7
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Kirkpatrick M. The Evolution of Genome Structure by Natural and Sexual Selection. J Hered 2016; 108:3-11. [PMID: 27388336 DOI: 10.1093/jhered/esw041] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/28/2016] [Indexed: 11/13/2022] Open
Abstract
Progress on understanding how genome structure evolves is accelerating with the arrival of new genomic, comparative, and theoretical approaches. This article reviews progress in understanding how chromosome inversions and sex chromosomes evolve, and how their evolution affects species' ecology. Analyses of clines in inversion frequencies in flies and mosquitoes imply strong local adaptation, and roles for both over- and under dominant selection. Those results are consistent with the hypothesis that inversions become established when they capture locally adapted alleles. Inversions can carry alleles that are beneficial to closely related species, causing them to introgress following hybridization. Models show that this "adaptive cassette" scenario can trigger large range expansions, as recently happened in malaria mosquitoes. Sex chromosomes are the most rapidly evolving genome regions of some taxa. Sexually antagonistic selection may be the key force driving transitions of sex determination between different pairs of chromosomes and between XY and ZW systems. Fusions between sex-chromosomes and autosomes most often involve the Y chromosome, a pattern that can be explained if fusions are mildly deleterious and fix by drift. Sexually antagonistic selection is one of several hypotheses to explain the recent discovery that the sex determination system has strong effects on the adult sex ratios of tetrapods. The emerging view of how genome structure evolves invokes a much richer constellation of forces than was envisioned during the Golden Age of research on Drosophila karyotypes.
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Affiliation(s)
- Mark Kirkpatrick
- From the Department of Integrative Biology C-0990, University of Texas, Austin, TX 78712 USA (Kirkpatrick).
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8
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Kelleher J, Etheridge AM, McVean G. Efficient Coalescent Simulation and Genealogical Analysis for Large Sample Sizes. PLoS Comput Biol 2016; 12:e1004842. [PMID: 27145223 PMCID: PMC4856371 DOI: 10.1371/journal.pcbi.1004842] [Citation(s) in RCA: 328] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/02/2016] [Indexed: 01/23/2023] Open
Abstract
A central challenge in the analysis of genetic variation is to provide realistic genome simulation across millions of samples. Present day coalescent simulations do not scale well, or use approximations that fail to capture important long-range linkage properties. Analysing the results of simulations also presents a substantial challenge, as current methods to store genealogies consume a great deal of space, are slow to parse and do not take advantage of shared structure in correlated trees. We solve these problems by introducing sparse trees and coalescence records as the key units of genealogical analysis. Using these tools, exact simulation of the coalescent with recombination for chromosome-sized regions over hundreds of thousands of samples is possible, and substantially faster than present-day approximate methods. We can also analyse the results orders of magnitude more quickly than with existing methods. Our understanding of the distribution of genetic variation in natural populations has been driven by mathematical models of the underlying biological and demographic processes. A key strength of such coalescent models is that they enable efficient simulation of data we might see under a variety of evolutionary scenarios. However, current methods are not well suited to simulating genome-scale data sets on hundreds of thousands of samples, which is essential if we are to understand the data generated by population-scale sequencing projects. Similarly, processing the results of large simulations also presents researchers with a major challenge, as it can take many days just to read the data files. In this paper we solve these problems by introducing a new way to represent information about the ancestral process. This new representation leads to huge gains in simulation speed and storage efficiency so that large simulations complete in minutes and the output files can be processed in seconds.
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Affiliation(s)
- Jerome Kelleher
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | | | - Gilean McVean
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Department of Statistics, University of Oxford, Oxford, United Kingdom
- Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom
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9
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Rane RV, Rako L, Kapun M, Lee SF, Hoffmann AA. Genomic evidence for role of inversion 3RP of Drosophila melanogaster in facilitating climate change adaptation. Mol Ecol 2015; 24:2423-32. [PMID: 25789416 DOI: 10.1111/mec.13161] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 01/14/2023]
Abstract
Chromosomal inversion polymorphisms are common in animals and plants, and recent models suggest that alternative arrangements spread by capturing different combinations of alleles acting additively or epistatically to favour local adaptation. It is also thought that inversions typically maintain favoured combinations for a long time by suppressing recombination between alternative chromosomal arrangements. Here, we consider patterns of linkage disequilibrium and genetic divergence in an old inversion polymorphism in Drosophila melanogaster (In(3R)Payne) known to be associated with climate change adaptation and a recent invasion event into Australia. We extracted, karyotyped and sequenced whole chromosomes from two Australian populations, so that changes in the arrangement of the alleles between geographically separated tropical and temperate areas could be compared. Chromosome-wide linkage disequilibrium (LD) analysis revealed strong LD within the region spanned by In(3R)Payne. This genomic region also showed strong differentiation between the tropical and the temperate populations, but no differentiation between different karyotypes from the same population, after controlling for chromosomal arrangement. Patterns of differentiation across the chromosome arm and in gene ontologies were enhanced by the presence of the inversion. These data support the notion that inversions are strongly selected by bringing together combinations of genes, but it is still not clear if such combinations act additively or epistatically. Our data suggest that climatic adaptation through inversions can be dynamic, reflecting changes in the relative abundance of different forms of an inversion and ongoing evolution of allelic content within an inversion.
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Affiliation(s)
- Rahul V Rane
- School of Biosciences, Bio21 Institute, University of Melbourne, 30 Flemington Road, Parkville, Vic., 3010, Australia
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10
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Arenas M. Advances in computer simulation of genome evolution: toward more realistic evolutionary genomics analysis by approximate bayesian computation. J Mol Evol 2015; 80:189-92. [PMID: 25808249 DOI: 10.1007/s00239-015-9673-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/19/2015] [Indexed: 11/29/2022]
Abstract
NGS technologies present a fast and cheap generation of genomic data. Nevertheless, ancestral genome inference is not so straightforward due to complex evolutionary processes acting on this material such as inversions, translocations, and other genome rearrangements that, in addition to their implicit complexity, can co-occur and confound ancestral inferences. Recently, models of genome evolution that accommodate such complex genomic events are emerging. This letter explores these novel evolutionary models and proposes their incorporation into robust statistical approaches based on computer simulations, such as approximate Bayesian computation, that may produce a more realistic evolutionary analysis of genomic data. Advantages and pitfalls in using these analytical methods are discussed. Potential applications of these ancestral genomic inferences are also pointed out.
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Affiliation(s)
- Miguel Arenas
- Centre for Molecular Biology "Severo Ochoa", Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (CSIC-UAM), C/Nicolás Cabrera, 1, Cantoblanco, 28049, Madrid, Spain,
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11
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Matrix inversions for chromosomal inversions: a method to construct summary statistics in complex coalescent models. Theor Popul Biol 2014; 97:1-10. [PMID: 25091264 DOI: 10.1016/j.tpb.2014.07.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 07/09/2014] [Accepted: 07/22/2014] [Indexed: 12/27/2022]
Abstract
Chromosomal inversions allow genetic divergence of locally adapted populations by reducing recombination between chromosomes with different arrangements. While patterns of genetic variation within inverted regions are increasingly documented, inferential methods are largely missing to analyze such data. Previous work has provided expectations for coalescence patterns of neutral sites linked to an inversion polymorphism in two locally adapted populations. Here, we define a method to construct summary statistics in such complex population structure models. Under a scenario of selection on the inversion breakpoints, we first construct estimators of the migration rate between the two habitats, and of the recombination rate of a nucleotide site between the two inversion backgrounds. Next, we analyze the disequilibrium between two sites within an inversion and provide an estimator of the distinct recombination rate between these two sites in homokaryotypes and heterokaryotypes. These estimators should be suitable summary statistics for simulation-based methods that can handle the complex dependences in the data.
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12
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Koch E, Ristroph M, Kirkpatrick M. Long range linkage disequilibrium across the human genome. PLoS One 2013; 8:e80754. [PMID: 24349013 PMCID: PMC3861250 DOI: 10.1371/journal.pone.0080754] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/17/2013] [Indexed: 11/19/2022] Open
Abstract
Long-range linkage disequilibria (LRLD) between sites that are widely separated on chromosomes may suggest that population admixture, epistatic selection, or other evolutionary forces are at work. We quantified patterns of LRLD on a chromosome-wide level in the YRI population of the HapMap dataset of single nucleotide polymorphisms (SNPs). We calculated the disequilibrium between all pairs of SNPs on each chromosome (a total of >2×10(11) values) and evaluated significance of overall disequilibrium using randomization. The results show an excess of associations between pairs of distant sites (separated by >0.25 cM) on all of the 22 autosomes. We discuss possible explanations for this observation.
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Affiliation(s)
- Evan Koch
- Department of Integrative Biology, University of Texas, Austin, Texas, United States of America
| | - Mickey Ristroph
- Department of Integrative Biology, University of Texas, Austin, Texas, United States of America
| | - Mark Kirkpatrick
- Department of Integrative Biology, University of Texas, Austin, Texas, United States of America
- * E-mail:
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