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Marques DA, Jones FC, Di Palma F, Kingsley DM, Reimchen TE. Genomic changes underlying repeated niche shifts in an adaptive radiation. Evolution 2022; 76:1301-1319. [PMID: 35398888 PMCID: PMC9320971 DOI: 10.1111/evo.14490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 01/21/2023]
Abstract
In adaptive radiations, single lineages rapidly diversify by adapting to many new niches. Little is known yet about the genomic mechanisms involved, that is, the source of genetic variation or genomic architecture facilitating or constraining adaptive radiation. Here, we investigate genomic changes associated with repeated invasion of many different freshwater niches by threespine stickleback in the Haida Gwaii archipelago, Canada, by resequencing single genomes from one marine and 28 freshwater populations. We find 89 likely targets of parallel selection in the genome that are enriched for old standing genetic variation. In contrast to theoretical expectations, their genomic architecture is highly dispersed with little clustering. Candidate genes and genotype-environment correlations match the three major environmental axes predation regime, light environment, and ecosystem size. In a niche space with these three dimensions, we find that the more divergent a new niche from the ancestral marine habitat, the more loci show signatures of parallel selection. Our findings suggest that the genomic architecture of parallel adaptation in adaptive radiation depends on the steepness of ecological gradients and the dimensionality of the niche space.
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Affiliation(s)
- David A. Marques
- Department of BiologyUniversity of VictoriaVictoriaBCV8W 3N5Canada
- Aquatic Ecology and Evolution, Institute of Ecology and EvolutionUniversity of BernBernCH‐3012Switzerland
- Department of Fish Ecology and Evolution, Centre for Ecology, Evolution, and BiogeochemistrySwiss Federal Institute of Aquatic Science and Technology (EAWAG), Eawag ‐ Swiss Federal Institute of Aquatic Science and TechnologyKastanienbaumCH‐6047Switzerland
- Natural History Museum BaselBaselCH‐4051Switzerland
| | - Felicity C. Jones
- Howard Hughes Medical Institute, Stanford University School of MedicineStanfordCalifornia94305USA
- Department of Developmental BiologyStanford University School of MedicineStanfordCalifornia94305USA
- Friedrich Miescher Laboratory of the Max Planck SocietyTübingen72076Germany
| | - Federica Di Palma
- Earlham InstituteNorwichNR4 7UZUnited Kingdom
- Department of Biological SciencesUniversity of East AngliaNorwichNR4 7TJUnited Kingdom
| | - David M. Kingsley
- Howard Hughes Medical Institute, Stanford University School of MedicineStanfordCalifornia94305USA
- Department of Developmental BiologyStanford University School of MedicineStanfordCalifornia94305USA
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2
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Sabatino SJ, Pereira P, Carneiro M, Dilytė J, Archer JP, Munoz A, Nonnis-Marzano F, Murias A. The genetics of adaptation in freshwater Eurasian shad ( Alosa). Ecol Evol 2022; 12:e8908. [PMID: 35646309 PMCID: PMC9130566 DOI: 10.1002/ece3.8908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 11/10/2022] Open
Abstract
Studying the genetics of phenotypic convergence can yield important insights into adaptive evolution. Here, we conducted a comparative genomic study of four lineages (species and subspecies) of anadromous shad (Alosa) that have independently evolved life cycles entirely completed in freshwater. Three naturally diverged (A. fallax lacustris, A. f. killarnensis, and A. macedonica), and the fourth (A. alosa) was artificially landlocked during the last century. To conduct this analysis, we assembled and annotated a draft of the A. alosa genome and generated whole‐genome sequencing for 16 anadromous and freshwater populations of shad. Widespread evidence for parallel genetic changes in freshwater populations within lineages was found. In freshwater A. alosa, which have only been diverging for tens of generations, this shows that parallel adaptive evolution can rapidly occur. However, parallel genetic changes across lineages were comparatively rare. The degree of genetic parallelism was not strongly related to the number of shared polymorphisms between lineages, thus suggesting that other factors such as divergence among ancestral populations or environmental variation may influence genetic parallelism across these lineages. These overall patterns were exemplified by genetic differentiation involving a paralog of ATPase‐α1 that appears to be under selection in just two of the more distantly related lineages studied, A. f. lacustris and A. alosa. Our findings provide insights into the genetic architecture of adaptation and parallel evolution along a continuum of population divergence.
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Affiliation(s)
- Stephen J Sabatino
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal.,Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal
| | - Paulo Pereira
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal.,Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal
| | - Miguel Carneiro
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal.,Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal
| | - Jolita Dilytė
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal
| | - John Patrick Archer
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal
| | - Antonio Munoz
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal
| | - Francesco Nonnis-Marzano
- Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal.,Department of Chemistry, Life Sciences and Environmental Sustainability Università di Parma Parma Italy
| | - Antonio Murias
- CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal.,BIOPOLIS - Program in Genomics, Biodiversity and Land Planning CIBIO Vairão Portugal.,Departamento de Biologia Faculdade de Ciências Universidade do Porto Porto Portugal
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3
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Shi Y, Bouska KL, McKinney GJ, Dokai W, Bartels A, McPhee MV, Larson WA. Gene flow influences the genomic architecture of local adaptation in six riverine fish species. Mol Ecol 2021; 32:1549-1566. [PMID: 34878685 DOI: 10.1111/mec.16317] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/15/2021] [Accepted: 12/01/2021] [Indexed: 11/30/2022]
Abstract
Understanding how gene flow influences adaptive divergence is important for predicting adaptive responses. Theoretical studies suggest that when gene flow is high, clustering of adaptive genes in fewer genomic regions would protect adaptive alleles from recombination and thus be selected for, but few studies have tested it with empirical data. Here, we used restriction site-associated sequencing to generate genomic data for six fish species with contrasting life histories from six reaches of the Upper Mississippi River System, USA. We used four differentiation-based outlier tests and three genotype-environment association analyses to define neutral single nucleotide polymorphisms (SNPs) and outlier SNPs that were putatively under selection. We then examined the distribution of outlier SNPs along the genome and investigated whether these SNPs were found in genomic islands of differentiation and inversions. We found that gene flow varied among species, and outlier SNPs were clustered more tightly in species with higher gene flow. The two species with the highest overall FST (0.0303-0.0720) and therefore lowest gene flow showed little evidence of clusters of outlier SNPs, with outlier SNPs in these species spreading uniformly across the genome. In contrast, nearly all outlier SNPs in the species with the lowest FST (0.0003) were found in a single large putative inversion. Two other species with intermediate gene flow (FST ~ 0.0025-0.0050) also showed clustered genomic architectures, with most islands of differentiation clustered on a few chromosomes. Our results provide important empirical evidence to support the hypothesis that increasingly clustered architecture of local adaptation is associated with high gene flow.
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Affiliation(s)
- Yue Shi
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA.,Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Kristen L Bouska
- U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, USA
| | - Garrett J McKinney
- NRC Research Associateship Program, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
| | - William Dokai
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA.,Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Andrew Bartels
- Long Term Resource Monitoring Program, Wisconsin Department of Natural Resources, La Crosse, Wisconsin, USA
| | - Megan V McPhee
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA
| | - Wesley A Larson
- National Oceanographic and Atmospheric Administration, Auke Bay Laboratories, National Marine Fisheries Service, Alaska Fisheries Science Center, Juneau, Alaska, USA.,U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
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4
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Salisbury SJ, Ruzzante DE. Genetic Causes and Consequences of Sympatric Morph Divergence in Salmonidae: A Search for Mechanisms. Annu Rev Anim Biosci 2021; 10:81-106. [PMID: 34758272 DOI: 10.1146/annurev-animal-051021-080709] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Repeatedly and recently evolved sympatric morphs exhibiting consistent phenotypic differences provide natural experimental replicates of speciation. Because such morphs are observed frequently in Salmonidae, this clade provides a rare opportunity to uncover the genomic mechanisms underpinning speciation. Such insight is also critical for conserving salmonid diversity, the loss of which could have significant ecological and economic consequences. Our review suggests that genetic differentiation among sympatric morphs is largely nonparallel apart from a few key genes that may be critical for consistently driving morph differentiation. We discuss alternative levels of parallelism likely underlying consistent morph differentiation and identify several factors that may temper this incipient speciation between sympatric morphs, including glacial history and contemporary selective pressures. Our synthesis demonstrates that salmonids are useful for studying speciation and poses additional research questions to be answered by future study of this family. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- S J Salisbury
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada; ,
| | - D E Ruzzante
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada; ,
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5
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Winkelmüller TM, Entila F, Anver S, Piasecka A, Song B, Dahms E, Sakakibara H, Gan X, Kułak K, Sawikowska A, Krajewski P, Tsiantis M, Garrido-Oter R, Fukushima K, Schulze-Lefert P, Laurent S, Bednarek P, Tsuda K. Gene expression evolution in pattern-triggered immunity within Arabidopsis thaliana and across Brassicaceae species. THE PLANT CELL 2021; 33:1863-1887. [PMID: 33751107 PMCID: PMC8290292 DOI: 10.1093/plcell/koab073] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 02/24/2021] [Indexed: 05/20/2023]
Abstract
Plants recognize surrounding microbes by sensing microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). Despite their significance for microbial control, the evolution of PTI responses remains largely uncharacterized. Here, by employing comparative transcriptomics of six Arabidopsis thaliana accessions and three additional Brassicaceae species to investigate PTI responses, we identified a set of genes that commonly respond to the MAMP flg22 and genes that exhibit species-specific expression signatures. Variation in flg22-triggered transcriptome responses across Brassicaceae species was incongruent with their phylogeny, while expression changes were strongly conserved within A. thaliana. We found the enrichment of WRKY transcription factor binding sites in the 5'-regulatory regions of conserved and species-specific responsive genes, linking the emergence of WRKY-binding sites with the evolution of gene expression patterns during PTI. Our findings advance our understanding of the evolution of the transcriptome during biotic stress.
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Affiliation(s)
- Thomas M Winkelmüller
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Frederickson Entila
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Shajahan Anver
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Present address: Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Anna Piasecka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Baoxing Song
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Present address: Institute for Genomic Diversity, Cornell University, Ithaca, New York
| | - Eik Dahms
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Hitoshi Sakakibara
- RIKEN Center for Sustainable Resource Science, 230-0045 Yokohama, Japan
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Xiangchao Gan
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Karolina Kułak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
- Present address: Department of Computational Biology, Adam Mickiewicz University, 61-614 Poznań, Poland
| | - Aneta Sawikowska
- Department of Mathematical and Statistical Methods, Poznań University of Life Sciences, 60-628 Poznań, Poland
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznań, Poland
| | - Paweł Krajewski
- Institute of Plant Genetics, Polish Academy of Sciences, 60-479 Poznań, Poland
| | - Miltos Tsiantis
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Ruben Garrido-Oter
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Kenji Fukushima
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, 97082 Würzburg, Germany
| | - Paul Schulze-Lefert
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Stefan Laurent
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
| | - Paweł Bednarek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Kenichi Tsuda
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Interdisciplinary Science Research Institute, Huazhong Agricultural University, 430070 Wuhan, China
- The Provincial Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, 430070 Wuhan, China
- Department of Plant–Microbe Interactions, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
- Author for correspondence:
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6
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Seabra SG, Rodrigues AS, Silva SE, Neto AC, Pina-Martins F, Marabuto E, Thompson V, Wilson MR, Yurtsever S, Halkka A, Rebelo MT, Borges PA, Quartau JA, Jiggins CD, Paulo OS. Population structure, adaptation and divergence of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), revealed by genomic and morphological data. PeerJ 2021; 9:e11425. [PMID: 34131518 PMCID: PMC8176912 DOI: 10.7717/peerj.11425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/17/2021] [Indexed: 11/20/2022] Open
Abstract
Understanding patterns of population differentiation and gene flow in insect vectors of plant diseases is crucial for the implementation of management programs of disease. We investigated morphological and genome-wide variation across the distribution range of the spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Auchenorrhyncha, Aphrophoridae), presently the most important vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. We found genome-wide divergence between P. spumarius and a very closely related species, P. tesselatus Melichar, 1899, at RAD sequencing markers. The two species may be identified by the morphology of male genitalia but are not differentiated at mitochondrial COI, making DNA barcoding with this gene ineffective. This highlights the importance of using integrative approaches in taxonomy. We detected admixture between P. tesselatus from Morocco and P. spumarius from the Iberian Peninsula, suggesting gene-flow between them. Within P. spumarius, we found a pattern of isolation-by-distance in European populations, likely acting alongside other factors restricting gene flow. Varying levels of co-occurrence of different lineages, showing heterogeneous levels of admixture, suggest other isolation mechanisms. The transatlantic populations of North America and Azores were genetically closer to the British population analyzed here, suggesting an origin from North-Western Europe, as already detected with mitochondrial DNA. Nevertheless, these may have been produced through different colonization events. We detected SNPs with signatures of positive selection associated with environmental variables, especially related to extremes and range variation in temperature and precipitation. The population genomics approach provided new insights into the patterns of divergence, gene flow and adaptation in these spittlebugs and led to several hypotheses that require further local investigation.
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Affiliation(s)
- Sofia G. Seabra
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Ana S.B. Rodrigues
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Sara E. Silva
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Ana Carina Neto
- CESAM - Centre for Environmental and Marine Studies, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Francisco Pina-Martins
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Eduardo Marabuto
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | | | - Michael R. Wilson
- National Museum of Wales, Department of Natural Sciences, Cardiff, United Kingdom
| | - Selçuk Yurtsever
- Trakya University, Biology Department, Science Faculty, Edirne, Turkey
| | - Antti Halkka
- Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Maria Teresa Rebelo
- CESAM - Centre for Environmental and Marine Studies, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Paulo A.V. Borges
- cE3c - Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, Faculty of Agriculture and Environment, Department of Environmental Sciences and Engineering, Universidade dos Açores, Angra do Heroísmo, Açores, Portugal
| | - José A. Quartau
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Chris D. Jiggins
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Octávio S. Paulo
- E3c - Centre for Ecology, Evolution and Environmental Changes, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
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7
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Flanagan SP, Rose E, Jones AG. The population genomics of repeated freshwater colonizations by Gulf pipefish. Mol Ecol 2021; 30:1672-1687. [PMID: 33580570 DOI: 10.1111/mec.15841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 12/30/2020] [Accepted: 02/01/2021] [Indexed: 12/17/2022]
Abstract
How organisms adapt to the novel challenges imposed by the colonization of a new habitat has long been a central question in evolutionary biology. When multiple populations of the same species independently adapt to similar environmental challenges, the question becomes whether the populations have arrived at their adaptations through the same genetic mechanisms. In recent years, genetic techniques have been used to tackle these questions by investigating the genome-level changes underlying local adaptation. Here, we present a genomic analysis of colonization of freshwater habitats by a primarily marine fish, the Gulf pipefish (Syngnathus scovelli). We sample pipefish from four geographically distinct freshwater locations and use double-digest restriction site associated DNA sequencing to compare them to 12 previously studied saltwater populations. The two most geographically distant and isolated freshwater populations are the most genetically distinct, although demographic analysis suggests that these populations are experiencing ongoing migration with their saltwater neighbours. Additionally, outlier regions were found genome-wide, showing parallelism across ecotype pairs. We conclude that these multiple freshwater colonizations involve similar genomic regions, despite the large geographical distances and different underlying mechanisms. These similar patterns are probably facilitated by the interacting effects of intrinsic barriers, gene flow among populations and ecological selection in the Gulf pipefish.
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Affiliation(s)
- Sarah P Flanagan
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Emily Rose
- Department of Biology, Valdosta State University, Valdosta, GA, USA
| | - Adam G Jones
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
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8
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Becher H, Brown MR, Powell G, Metherell C, Riddiford NJ, Twyford AD. Maintenance of Species Differences in Closely Related Tetraploid Parasitic Euphrasia (Orobanchaceae) on an Isolated Island. PLANT COMMUNICATIONS 2020; 1:100105. [PMID: 33367265 PMCID: PMC7748025 DOI: 10.1016/j.xplc.2020.100105] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/24/2020] [Accepted: 08/27/2020] [Indexed: 05/02/2023]
Abstract
Polyploidy is pervasive in angiosperm evolution and plays important roles in adaptation and speciation. However, polyploid groups are understudied due to complex sequence homology, challenging genome assembly, and taxonomic complexity. Here, we study adaptive divergence in taxonomically complex eyebrights (Euphrasia), where recent divergence, phenotypic plasticity, and hybridization blur species boundaries. We focus on three closely related tetraploid species with contrasting ecological preferences that are sympatric on Fair Isle, a small isolated island in the British Isles. Using a common garden experiment, we show a genetic component to the morphological differences present between these species. Using whole-genome sequencing and a novel k-mer approach we call "Tetmer", we demonstrate that the species are of allopolyploid origin, with a sub-genome divergence of approximately 5%. Using ∼2 million SNPs, we show sub-genome homology across species, with a very low sequence divergence characteristic of recent speciation. This genetic variation is broadly structured by species, with clear divergence of Fair Isle heathland Euphrasia micrantha, while grassland Euphrasia arctica and coastal Euphrasia foulaensis are more closely related. Overall, we show that tetraploid Euphrasia is a system of allopolyploids of postglacial species divergence, where adaptation to novel environments may be conferred by old variants rearranged into new genetic lineages.
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Affiliation(s)
- Hannes Becher
- University of Edinburgh, School of Biological Sciences, Institute of Evolutionary Biology, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
- Corresponding author
| | - Max R. Brown
- University of Edinburgh, School of Biological Sciences, Institute of Evolutionary Biology, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Gavin Powell
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, UK
| | - Chris Metherell
- Botanical Society of Britain and Ireland, 4 High Firs Crescent, Harpenden, Hertfordshire AL5 1NA, UK
| | | | - Alex D. Twyford
- University of Edinburgh, School of Biological Sciences, Institute of Evolutionary Biology, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR, UK
- Corresponding author
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9
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Terekhanova NV, Barmintseva AE, Kondrashov AS, Bazykin GA, Mugue NS. Architecture of Parallel Adaptation in Ten Lacustrine Threespine Stickleback Populations from the White Sea Area. Genome Biol Evol 2020; 11:2605-2618. [PMID: 31406984 PMCID: PMC6761963 DOI: 10.1093/gbe/evz175] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2019] [Indexed: 12/20/2022] Open
Abstract
Adaptation of threespine stickleback to freshwater involves parallel recruitment of freshwater alleles in clusters of closely linked sites, or divergence islands (DIs). However, it remains unclear to what extent the DIs and the alleles that constitute them coincide between populations that underwent adaptation to freshwater independently. We examine threespine sticklebacks from ten freshwater lakes that emerged 500–1500 years ago in the White Sea basin, with the emphasis on repeatability of genomic patterns of adaptation among the lake populations and the role of local recombination rate in the distribution and structure of DIs. The 65 detected DIs are clustered in the genome, forming 12 aggregations, and this clustering cannot be explained by the variation of the recombination rate. Only 21 of the DIs are present in all the freshwater populations, likely being indispensable for successful colonization of freshwater environment by the ancestral marine population. Within most DIs, the same set of single nucleotide polymorphisms (SNPs) distinguish marine and freshwater haplotypes in all the lake populations; however, in some DIs, freshwater alleles differ between populations, suggesting that they could have been established by recruitment of different haplotypes in different populations.
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Affiliation(s)
- Nadezhda V Terekhanova
- Skolkovo Institute of Science and Technology, Skolkovo, Russia.,Sector for Molecular Evolution, Institute for Information Transmission Problems of the RAS (Kharkevich Institute), Moscow, Russia
| | - Anna E Barmintseva
- Laboratory of Molecular Genetics, Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia
| | - Alexey S Kondrashov
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan.,M. V. Lomonosov Moscow State University, Moscow, Russia
| | - Georgii A Bazykin
- Skolkovo Institute of Science and Technology, Skolkovo, Russia.,Sector for Molecular Evolution, Institute for Information Transmission Problems of the RAS (Kharkevich Institute), Moscow, Russia
| | - Nikolai S Mugue
- Laboratory of Molecular Genetics, Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia.,N. K. Koltzov Institute of Developmental Biology RAS, Moscow, Russia
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10
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Huang Y, Feulner PGD, Eizaguirre C, Lenz TL, Bornberg-Bauer E, Milinski M, Reusch TBH, Chain FJJ. Genome-Wide Genotype-Expression Relationships Reveal Both Copy Number and Single Nucleotide Differentiation Contribute to Differential Gene Expression between Stickleback Ecotypes. Genome Biol Evol 2020; 11:2344-2359. [PMID: 31298693 PMCID: PMC6735750 DOI: 10.1093/gbe/evz148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2019] [Indexed: 12/11/2022] Open
Abstract
Repeated and independent emergence of trait divergence that matches habitat differences is a sign of parallel evolution by natural selection. Yet, the molecular underpinnings that are targeted by adaptive evolution often remain elusive. We investigate this question by combining genome-wide analyses of copy number variants (CNVs), single nucleotide polymorphisms (SNPs), and gene expression across four pairs of lake and river populations of the three-spined stickleback (Gasterosteus aculeatus). We tested whether CNVs that span entire genes and SNPs occurring in putative cis-regulatory regions contribute to gene expression differences between sticklebacks from lake and river origins. We found 135 gene CNVs that showed a significant positive association between gene copy number and gene expression, suggesting that CNVs result in dosage effects that can fuel phenotypic variation and serve as substrates for habitat-specific selection. Copy number differentiation between lake and river sticklebacks also contributed to expression differences of two immune-related genes in immune tissues, cathepsin A and GIMAP7. In addition, we identified SNPs in cis-regulatory regions (eSNPs) associated with the expression of 1,865 genes, including one eSNP upstream of a carboxypeptidase gene where both the SNP alleles differentiated and the gene was differentially expressed between lake and river populations. Our study highlights two types of mutations as important sources of genetic variation involved in the evolution of gene expression and in potentially facilitating repeated adaptation to novel environments.
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Affiliation(s)
- Yun Huang
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Biodiversity Research Center, Academia Sinica, Taipei, Taiwan, ROC
| | - Philine G D Feulner
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution and Biogeochemistry, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Switzerland
| | - Christophe Eizaguirre
- School of Biological and Chemical Sciences, Queen Mary University of London, United Kingdom
| | - Tobias L Lenz
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Erich Bornberg-Bauer
- Evolutionary Bioinformatics, Institute for Evolution and Biodiversity, Westfälische Wilhelms University, Münster, Germany
| | - Manfred Milinski
- Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Thorsten B H Reusch
- Marine Evolutionary Ecology, GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
| | - Frédéric J J Chain
- Department of Biological Sciences, University of Massachusetts Lowell, USA
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11
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Costa D, Sotelo G, Kaliontzopoulou A, Carvalho J, Butlin R, Hollander J, Faria R. Hybridization patterns between two marine snails, Littorina fabalis and L. obtusata. Ecol Evol 2020; 10:1158-1179. [PMID: 32076505 PMCID: PMC7029087 DOI: 10.1002/ece3.5943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/21/2019] [Accepted: 11/27/2019] [Indexed: 01/22/2023] Open
Abstract
Characterizing the patterns of hybridization between closely related species is crucial to understand the role of gene flow in speciation. In particular, systems comprising multiple contacts between sister species offer an outstanding opportunity to investigate how reproductive isolation varies with environmental conditions, demography and geographic contexts of divergence. The flat periwinkles, Littorina obtusata and L. fabalis (Gastropoda), are two intertidal sister species with marked ecological differences compatible with late stages of speciation. Although hybridization between the two was previously suggested, its extent across the Atlantic shores of Europe remained largely unknown. Here, we combined genetic (microsatellites and mtDNA) and morphological data (shell and male genital morphology) from multiple populations of flat periwinkles in north-western Iberia to assess the extent of current and past hybridization between L. obtusata and L. fabalis under two contrasting geographic settings of divergence (sympatry and allopatry). Hybridization signatures based on both mtDNA and microsatellites were stronger in sympatric sites, although evidence for recent extensive admixture was found in a single location. Misidentification of individuals into species based on shell morphology was higher in sympatric than in allopatric sites. However, despite hybridization, species distinctiveness based on this phenotypic trait together with male genital morphology remained relatively high. The observed variation in the extent of hybridization among locations provides a rare opportunity for future studies on the consequences of different levels of gene flow for reinforcement, thus informing about the mechanisms underlying the completion of speciation.
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Affiliation(s)
- Diana Costa
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- Department of BiologyFaculty of SciencesUniversity of PortoPortoPortugal
- CIIMARInterdisciplinary Centre of Marine and Environmental ResearchUniversity of PortoPortoPortugal
| | - Graciela Sotelo
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
| | - Antigoni Kaliontzopoulou
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
| | - João Carvalho
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- cE3cCentre for Ecology, Evolution and Environmental ChangesDepartamento de Biologia AnimalFaculdade de Ciências da Universidade de LisboaLisbonPortugal
| | - Roger Butlin
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
- Department of Marine SciencesUniversity of GothenburgGothenburgSweden
| | - Johan Hollander
- Department of BiologyAquatic Ecology UnitLund UniversityLundSweden
- Global Ocean InstituteWorld Maritime UniversityMalmöSweden
| | - Rui Faria
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- CIIMARInterdisciplinary Centre of Marine and Environmental ResearchUniversity of PortoPortoPortugal
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
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12
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Hood GR, Powell THQ, Doellman MM, Sim SB, Glover M, Yee WL, Goughnour RB, Mattsson M, Schwarz D, Feder JL. Rapid and repeatable host plant shifts drive reproductive isolation following a recent human-mediated introduction of the apple maggot fly, Rhagoletis pomonella. Evolution 2019; 74:156-168. [PMID: 31729753 DOI: 10.1111/evo.13882] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/24/2019] [Accepted: 10/27/2019] [Indexed: 01/26/2023]
Abstract
Ecological speciation via host-shifting is often invoked as a mechanism for insect diversification, but the relative importance of this process is poorly understood. The shift of Rhagoletis pomonella in the 1850s from the native downy hawthorn, Crataegus mollis, to introduced apple, Malus pumila, is a classic example of sympatric host race formation, a hypothesized early stage of ecological speciation. The accidental human-mediated introduction of R. pomonella into the Pacific Northwest (PNW) in the late 1970s allows us to investigate how novel ecological opportunities may trigger divergent adaptation and host race formation on a rapid timescale. Since the introduction, the fly has spread in the PNW, where in addition to apple, it now infests native black hawthorn, Crataegus douglasii, and introduced ornamental hawthorn, Crataegus monogyna. We use this "natural experiment" to test for genetic differentiation among apple, black, and ornamental hawthorn flies co-occurring at three sympatric sites. We report evidence that populations of all three host-associations are genetically differentiated at the local level, indicating that partial reproductive isolation has evolved in this novel habitat. Our results suggest that conditions suitable for initiating host-associated divergence may be common in nature, allowing for the rapid evolution of new host races when ecological opportunity arises.
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Affiliation(s)
- Glen R Hood
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, 48202
| | - Thomas H Q Powell
- Department of Biological Sciences, Binghamton University, Binghamton, New York, 13902
| | - Meredith M Doellman
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556
| | - Sheina B Sim
- USDA-ARS Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center, Hilo, Hawaii, 96720
| | - Mary Glover
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556
| | - Wee L Yee
- USDA-ARS Yakima Agricultural Research Laboratory, Wapato, Washington, 98951
| | | | - Monte Mattsson
- Environmental Services, City of Portland, Portland, Oregon, 97204
| | - Dietmar Schwarz
- Department of Biology, Western Washington University, Bellingham, Washington, 98225
| | - Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556.,Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, Indiana, 46556.,Environmental Change Initiative, University of Notre Dame, Notre Dame, Indiana, 46556
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13
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Wang X, Maher KH, Zhang N, Que P, Zheng C, Liu S, Wang B, Huang Q, Chen D, Yang X, Zhang Z, Székely T, Urrutia AO, Liu Y. Demographic Histories and Genome-Wide Patterns of Divergence in Incipient Species of Shorebirds. Front Genet 2019; 10:919. [PMID: 31781152 PMCID: PMC6857203 DOI: 10.3389/fgene.2019.00919] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 08/30/2019] [Indexed: 12/30/2022] Open
Abstract
Understanding how incipient species are maintained with gene flow is a fundamental question in evolutionary biology. Whole genome sequencing of multiple individuals holds great potential to illustrate patterns of genomic differentiation as well as the associated evolutionary histories. Kentish (Charadrius alexandrinus) and the white-faced (C. dealbatus) plovers, which differ in their phenotype, ecology and behavior, are two incipient species and parapatrically distributed in East Asia. Previous studies show evidence of genetic diversification with gene flow between the two plovers. Under this scenario, it is of great importance to explore the patterns of divergence at the genomic level and to determine whether specific regions are involved in reproductive isolation and local adaptation. Here we present the first population genomic analysis of the two incipient species based on the de novo Kentish plover reference genome and resequenced populations. We show that the two plover lineages are distinct in both nuclear and mitochondrial genomes. Using model-based coalescence analysis, we found that population sizes of Kentish plover increased whereas white-faced plovers declined during the Last Glaciation Period. Moreover, the two plovers diverged allopatrically, with gene flow occurring after secondary contact. This has resulted in low levels of genome-wide differentiation, although we found evidence of a few highly differentiated genomic regions in both the autosomes and the Z-chromosome. This study illustrates that incipient shorebird species with gene flow after secondary contact can exhibit discrete divergence at specific genomic regions and provides basis to further exploration on the genetic basis of relevant phenotypic traits.
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Affiliation(s)
- Xuejing Wang
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Kathryn H. Maher
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Nan Zhang
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Pinjia Que
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Chenqing Zheng
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Department of Bioinformatics, Shenzhen Realomics Biological Technology Ltd, Shenzhen, China
| | - Simin Liu
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Biao Wang
- School of Biosciences, University of Melbourne, Parkville, VIC, Australia
| | - Qin Huang
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - De Chen
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Xu Yang
- Department of Bioinformatics, Shenzhen Realomics Biological Technology Ltd, Shenzhen, China
| | - Zhengwang Zhang
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Tamás Székely
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Araxi O. Urrutia
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
- Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Yang Liu
- State Key Laboratory of Biocontrol, Department of Ecology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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14
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Rougeux C, Gagnaire P, Praebel K, Seehausen O, Bernatchez L. Polygenic selection drives the evolution of convergent transcriptomic landscapes across continents within a Nearctic sister species complex. Mol Ecol 2019; 28:4388-4403. [DOI: 10.1111/mec.15226] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/06/2019] [Accepted: 08/08/2019] [Indexed: 12/22/2022]
Affiliation(s)
- Clément Rougeux
- Département de biologie Institut de Biologie Intégrative et des Systèmes (IBIS) Université Laval Québec City QC Canada
| | | | - Kim Praebel
- Norwegian College of Fishery Science UiT The Arctic University of Norway Tromsø Norway
| | - Ole Seehausen
- Aquatic Ecology and Evolution Institute of Ecology & Evolution University of Bern Bern Switzerland
| | - Louis Bernatchez
- Département de biologie Institut de Biologie Intégrative et des Systèmes (IBIS) Université Laval Québec City QC Canada
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15
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Campbell CR, Poelstra JW, Yoder AD. What is Speciation Genomics? The roles of ecology, gene flow, and genomic architecture in the formation of species. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly063] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | - J W Poelstra
- Department of Biology, Duke University, Durham, NC, USA
| | - Anne D Yoder
- Department of Biology, Duke University, Durham, NC, USA
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16
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Jacobs A, Hughes MR, Robinson PC, Adams CE, Elmer KR. The Genetic Architecture Underlying the Evolution of a Rare Piscivorous Life History Form in Brown Trout after Secondary Contact and Strong Introgression. Genes (Basel) 2018; 9:genes9060280. [PMID: 29857499 PMCID: PMC6026935 DOI: 10.3390/genes9060280] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/16/2018] [Accepted: 05/17/2018] [Indexed: 01/17/2023] Open
Abstract
Identifying the genetic basis underlying phenotypic divergence and reproductive isolation is a longstanding problem in evolutionary biology. Genetic signals of adaptation and reproductive isolation are often confounded by a wide range of factors, such as variation in demographic history or genomic features. Brown trout (Salmo trutta) in the Loch Maree catchment, Scotland, exhibit reproductively isolated divergent life history morphs, including a rare piscivorous (ferox) life history form displaying larger body size, greater longevity and delayed maturation compared to sympatric benthivorous brown trout. Using a dataset of 16,066 SNPs, we analyzed the evolutionary history and genetic architecture underlying this divergence. We found that ferox trout and benthivorous brown trout most likely evolved after recent secondary contact of two distinct glacial lineages, and identified 33 genomic outlier windows across the genome, of which several have most likely formed through selection. We further identified twelve candidate genes and biological pathways related to growth, development and immune response potentially underpinning the observed phenotypic differences. The identification of clear genomic signals divergent between life history phenotypes and potentially linked to reproductive isolation, through size assortative mating, as well as the identification of the underlying demographic history, highlights the power of genomic studies of young species pairs for understanding the factors shaping genetic differentiation.
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Affiliation(s)
- Arne Jacobs
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
| | - Martin R Hughes
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
- Scottish Centre for Ecology and the Natural Environment, University of Glasgow, Rowardennan, Loch Lomond, Glasgow G63 0AW, Scotland, UK.
| | - Paige C Robinson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
| | - Colin E Adams
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
- Scottish Centre for Ecology and the Natural Environment, University of Glasgow, Rowardennan, Loch Lomond, Glasgow G63 0AW, Scotland, UK.
| | - Kathryn R Elmer
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
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17
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Rougeux C, Bernatchez L, Gagnaire PA. Modeling the Multiple Facets of Speciation-with-Gene-Flow toward Inferring the Divergence History of Lake Whitefish Species Pairs (Coregonus clupeaformis). Genome Biol Evol 2018; 9:2057-2074. [PMID: 28903535 PMCID: PMC5737413 DOI: 10.1093/gbe/evx150] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2017] [Indexed: 02/07/2023] Open
Abstract
Parallel divergence across replicated species pairs occurring in similar environmental contrasts may arise through distinct evolutionary scenarios. Deciphering whether such parallelism actually reflects repeated parallel divergence driven by divergent selection or a single divergence event with subsequent gene flow needs to be ascertained. Reconstructing historical gene flow is therefore of fundamental interest to understand how demography and selection jointly shaped genomic divergence during speciation. Here, we use an extended modeling framework to explore the multiple facets of speciation-with-gene-flow with demo-genetic divergence models that capture both temporal and genomic variation in effective population size and migration rate. We investigate the divergence history of replicate sympatric species pairs of Lake Whitefish (normal benthic and dwarf limnetic) characterized by variable degrees of ecological divergence and reproductive isolation. Genome-wide SNPs were used to document the extent of genetic differentiation in each species pair, and 26 divergence models were fitted and compared with the unfolded joint allele frequency spectrum of each pair. We found evidence that a recent (circa 3,000–4,000 generations) asymmetrical secondary contact between expanding postglacial populations has accompanied Whitefish diversification. Our results suggest that heterogeneous genomic differentiation has emerged through the combined effects of linked selection generating variable rates of lineage sorting across the genome during geographical isolation, and heterogeneous introgression eroding divergence at different rates across the genome upon secondary contact. This study thus provides a new retrospective insight into the historical demographic and selective processes that shaped a continuum of divergence associated with ecological speciation.
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Affiliation(s)
- Clément Rougeux
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Canada
| | - Louis Bernatchez
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Canada
| | - Pierre-Alexandre Gagnaire
- Université de Montpellier, Place Eugène Bataillon, France.,Institut des Sciences de l'Évolution de Montpellier-UMR 5554 UM-CNRS-IRD-EPHE, Place Eugène Bataillon, Montpellier, France
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18
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Nadeau NJ, Kawakami T. Population Genomics of Speciation and Admixture. POPULATION GENOMICS 2018. [DOI: 10.1007/13836_2018_24] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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19
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Peichel CL, Marques DA. The genetic and molecular architecture of phenotypic diversity in sticklebacks. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0486. [PMID: 27994127 DOI: 10.1098/rstb.2015.0486] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2016] [Indexed: 11/12/2022] Open
Abstract
A major goal of evolutionary biology is to identify the genotypes and phenotypes that underlie adaptation to divergent environments. Stickleback fish, including the threespine stickleback (Gasterosteus aculeatus) and the ninespine stickleback (Pungitius pungitius), have been at the forefront of research to uncover the genetic and molecular architecture that underlies phenotypic diversity and adaptation. A wealth of quantitative trait locus (QTL) mapping studies in sticklebacks have provided insight into long-standing questions about the distribution of effect sizes during adaptation as well as the role of genetic linkage in facilitating adaptation. These QTL mapping studies have also provided a basis for the identification of the genes that underlie phenotypic diversity. These data have revealed that mutations in regulatory elements play an important role in the evolution of phenotypic diversity in sticklebacks. Genetic and molecular studies in sticklebacks have also led to new insights on the genetic basis of repeated evolution and suggest that the same loci are involved about half of the time when the same phenotypes evolve independently. When the same locus is involved, selection on standing variation and repeated mutation of the same genes have both contributed to the evolution of similar phenotypes in independent populations.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
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Affiliation(s)
- Catherine L Peichel
- Divisions of Basic Sciences and Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - David A Marques
- Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland.,Department of Fish Ecology and Evolution, Eawag, Swiss Federal Institute for Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland
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20
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Ravinet M, Faria R, Butlin RK, Galindo J, Bierne N, Rafajlović M, Noor MAF, Mehlig B, Westram AM. Interpreting the genomic landscape of speciation: a road map for finding barriers to gene flow. J Evol Biol 2017; 30:1450-1477. [DOI: 10.1111/jeb.13047] [Citation(s) in RCA: 306] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 12/14/2022]
Affiliation(s)
- M. Ravinet
- Centre for Ecological and Evolutionary Synthesis; University of Oslo; Oslo Norway
- National Institute of Genetics; Mishima Shizuoka Japan
| | - R. Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos; InBIO, Laboratório Associado; Universidade do Porto; Vairão Portugal
- Department of Experimental and Health Sciences; IBE, Institute of Evolutionary Biology (CSIC-UPF); Pompeu Fabra University; Barcelona Spain
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - R. K. Butlin
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
- Department of Marine Sciences; Centre for Marine Evolutionary Biology; University of Gothenburg; Gothenburg Sweden
| | - J. Galindo
- Department of Biochemistry, Genetics and Immunology; University of Vigo; Vigo Spain
| | - N. Bierne
- CNRS; Université Montpellier; ISEM; Station Marine Sète France
| | - M. Rafajlović
- Department of Physics; University of Gothenburg; Gothenburg Sweden
| | | | - B. Mehlig
- Department of Physics; University of Gothenburg; Gothenburg Sweden
| | - A. M. Westram
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
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21
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Southcott L, Kronforst MR. A neutral view of the evolving genomic architecture of speciation. Ecol Evol 2017; 7:6358-6366. [PMID: 28861239 PMCID: PMC5574762 DOI: 10.1002/ece3.3190] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 05/18/2017] [Accepted: 05/21/2017] [Indexed: 11/18/2022] Open
Abstract
Analyses of genomewide polymorphism data have begun to shed light on speciation and adaptation. Genome scans to identify regions of the genome that are unusually different between populations or species, possibly due to divergent natural or sexual selection, are widespread in speciation genomics. Theoretical and empirical work suggests that such outlier regions may grow faster than linearly during speciation with gene flow due to a rapid transition between low and high reproductive isolation. We investigate whether this pattern could be attributed to neutral processes by simulating genomes under neutral evolution with varying amounts and timing of gene flow. Under both neutral evolution and divergent selection, simulations with little or no gene flow, or with a long allopatric period after its cessation, resulted in faster than linear growth of the proportion of the genome lying in outlier regions. Without selection, higher recent gene flow erased differentiation; with divergent selection, these same scenarios produced nonlinear growth to a plateau. Our results suggest that, given a history of gene flow, the growth of the divergent genome is informative about selection during divergence, but that in many scenarios, this pattern does not easily distinguish neutral and non-neutral processes during speciation with gene flow.
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Affiliation(s)
- Laura Southcott
- Committee on Evolutionary BiologyUniversity of ChicagoChicagoILUSA
| | - Marcus R. Kronforst
- Committee on Evolutionary BiologyUniversity of ChicagoChicagoILUSA
- Department of Ecology and EvolutionUniversity of ChicagoChicagoILUSA
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22
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Plekhanova E, Vishnyakova MA, Bulyntsev S, Chang PL, Carrasquilla-Garcia N, Negash K, Wettberg EV, Noujdina N, Cook DR, Samsonova MG, Nuzhdin SV. Genomic and phenotypic analysis of Vavilov's historic landraces reveals the impact of environment and genomic islands of agronomic traits. Sci Rep 2017; 7:4816. [PMID: 28684880 PMCID: PMC5500531 DOI: 10.1038/s41598-017-05087-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 05/24/2017] [Indexed: 12/30/2022] Open
Abstract
The Vavilov Institute of Plant Genetic Resources (VIR), in St. Petersburg, Russia, houses a unique genebank, with historical collections of landraces. When they were collected, the geographical distribution and genetic diversity of most crops closely reflected their historical patterns of cultivation established over the preceding millennia. We employed a combination of genomics, computational biology and phenotyping to characterize VIR's 147 chickpea accessions from Turkey and Ethiopia, representing chickpea's center of origin and a major location of secondary diversity. Genotyping by sequencing identified 14,059 segregating polymorphisms and genome-wide association studies revealed 28 GWAS hits in potential candidate genes likely to affect traits of agricultural importance. The proportion of polymorphisms shared among accessions is a strong predictor of phenotypic resemblance, and of environmental similarity between historical sampling sites. We found that 20 out of 28 polymorphisms, associated with multiple traits, including days to maturity, plant phenology, and yield-related traits such as pod number, localized to chromosome 4. We hypothesize that selection and introgression via inadvertent hybridization between more and less advanced morphotypes might have resulted in agricultural improvement genes being aggregated to genomic 'agro islands', and in genotype-to-phenotype relationships resembling widespread pleiotropy.
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Affiliation(s)
- Elena Plekhanova
- Department of Applied Mathematics, Peter the Great St.Petersburg Polytechnic University, St. Petersburg, Russia
| | - Margarita A Vishnyakova
- Federal Research Centre All-Russian N.I. Vavilov Institute of Plant Genetic Resources (VIR), St. Petersburg, Russia
| | - Sergey Bulyntsev
- Federal Research Centre All-Russian N.I. Vavilov Institute of Plant Genetic Resources (VIR), St. Petersburg, Russia
| | - Peter L Chang
- Department of Plant Pathology, University of California, Davis, CA, USA.,Program Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, USA
| | | | - Kassaye Negash
- Department of Plant Pathology, University of California, Davis, CA, USA
| | - Eric von Wettberg
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, USA
| | - Nina Noujdina
- School of Architecture, University of Southern California, Los Angeles, CA, USA
| | - Douglas R Cook
- Department of Plant Pathology, University of California, Davis, CA, USA
| | - Maria G Samsonova
- Department of Applied Mathematics, Peter the Great St.Petersburg Polytechnic University, St. Petersburg, Russia
| | - Sergey V Nuzhdin
- Department of Applied Mathematics, Peter the Great St.Petersburg Polytechnic University, St. Petersburg, Russia. .,Program Molecular and Computation Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, USA.
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23
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Ragland GJ, Doellman MM, Meyers PJ, Hood GR, Egan SP, Powell THQ, Hahn DA, Nosil P, Feder JL. A test of genomic modularity among life-history adaptations promoting speciation with gene flow. Mol Ecol 2017; 26:3926-3942. [DOI: 10.1111/mec.14178] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/12/2017] [Accepted: 04/14/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Gregory J. Ragland
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Environmental Change Initiative; University of Notre Dame; Notre Dame IN USA
- Department of Integrative Biology; University of Colorado - Denver; Denver CO USA
| | | | - Peter J. Meyers
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
| | - Glen R. Hood
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Biosciences; Rice University; Houston TX USA
| | - Scott P. Egan
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Biosciences; Rice University; Houston TX USA
- Advanced Diagnostics and Therapeutics Initiative; University of Notre Dame; Notre Dame IN USA
| | - Thomas H. Q. Powell
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Department of Entomology and Nematology; University of Florida; Gainesville FL USA
- Department of Biological Sciences; State University of New York - Binghamton; Binghamton NY USA
| | - Daniel A. Hahn
- Department of Entomology and Nematology; University of Florida; Gainesville FL USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - Jeffrey L. Feder
- Department of Biological Sciences; University of Notre Dame; Notre Dame IN USA
- Environmental Change Initiative; University of Notre Dame; Notre Dame IN USA
- Advanced Diagnostics and Therapeutics Initiative; University of Notre Dame; Notre Dame IN USA
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24
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Huuskonen H, Shikano T, Mehtätalo L, Kettunen J, Eronen R, Toiviainen A, Kekäläinen J. Anthropogenic environmental changes induce introgression in sympatric whitefish ecotypes. Biol J Linn Soc Lond 2017. [DOI: 10.1093/biolinnean/blx010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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25
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Hansen MM, Rogers SM. Recipient of the 2016 Molecular Ecology Prize: Louis Bernatchez - advancing the conservation of aquatic resources with his contributions on the ecological genomics of adaptation and speciation. Mol Ecol 2017; 26:413-419. [PMID: 28130941 DOI: 10.1111/mec.13941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael M Hansen
- Department of Bioscience, Aarhus University, Ny Munkegade 116., DK-8000, Aarhus C, Denmark
| | - Sean M Rogers
- Department of Biological Sciences, University of Calgary, 2500 University Dr., NW, Calgary, AB, T2N 1N4, Canada
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26
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Dion-Côté AM, Symonová R, Lamaze FC, Pelikánová Š, Ráb P, Bernatchez L. Standing chromosomal variation in Lake Whitefish species pairs: the role of historical contingency and relevance for speciation. Mol Ecol 2016; 26:178-192. [PMID: 27545583 DOI: 10.1111/mec.13816] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 08/08/2016] [Accepted: 08/11/2016] [Indexed: 12/19/2022]
Abstract
The role of chromosome changes in speciation remains a debated topic, although demographic conditions associated with divergence should promote their appearance. We tested a potential relationship between chromosome changes and speciation by studying two Lake Whitefish (Coregonus clupeaformis) lineages that recently colonized postglacial lakes following allopatry. A dwarf limnetic species evolved repeatedly from the normal benthic species, becoming reproductively isolated. Lake Whitefish hybrids experience mitotic and meiotic instability, which may result from structurally divergent chromosomes. Motivated by this observation, we test the hypothesis that chromosome organization differs between Lake Whitefish species pairs using cytogenetics. While chromosome and fundamental numbers are conserved between the species (2n = 80, NF = 98), we observe extensive polymorphism of subtle karyotype traits. We describe intrachromosomal differences associated with heterochromatin and repetitive DNA, and test for parallelism among three sympatric species pairs. Multivariate analyses support the hypothesis that differentiation at the level of subchromosomal markers mostly appeared during allopatry. Yet we find no evidence for parallelism between species pairs among lakes, consistent with colonization effect or postcolonization differentiation. The reported intrachromosomal polymorphisms do not appear to play a central role in driving adaptive divergence between normal and dwarf Lake Whitefish. We discuss how chromosomal differentiation in the Lake Whitefish system may contribute to the destabilization of mitotic and meiotic chromosome segregation in hybrids, as documented previously. The chromosome structures detected here are still difficult to sequence and assemble, demonstrating the value of cytogenetics as a complementary approach to understand the genomic bases of speciation.
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Affiliation(s)
- Anne-Marie Dion-Côté
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, 1030, Avenue de la Médecine, Québec, Québec, Canada, G1V 0A6
| | - Radka Symonová
- Research Institute for Limnology, University of Innsbruck, Mondseestraße 9, A-5310, Mondsee, Austria
| | - Fabien C Lamaze
- Ontario Institut for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario, Canada, M5G 0A3
| | - Šárka Pelikánová
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, AS CR, vvi, Liběchov, 277 21, Czech Republic
| | - Petr Ráb
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, AS CR, vvi, Liběchov, 277 21, Czech Republic
| | - Louis Bernatchez
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, 1030, Avenue de la Médecine, Québec, Québec, Canada, G1V 0A6
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27
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Hendrick MF, Finseth FR, Mathiasson ME, Palmer KA, Broder EM, Breigenzer P, Fishman L. The genetics of extreme microgeographic adaptation: an integrated approach identifies a major gene underlying leaf trichome divergence in Yellowstone Mimulus guttatus. Mol Ecol 2016; 25:5647-5662. [PMID: 27393073 DOI: 10.1111/mec.13753] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 06/15/2016] [Accepted: 06/22/2016] [Indexed: 12/30/2022]
Abstract
Microgeographic adaptation provides a particularly interesting context for understanding the genetic basis of phenotypic divergence and may also present unique empirical challenges. In particular, plant adaptation to extreme soil mosaics may generate barriers to gene flow or shifts in mating system that confound simple genomic scans for adaptive loci. Here, we combine three approaches - quantitative trait locus (QTL) mapping of candidate intervals in controlled crosses, population resequencing (PoolSeq) and analyses of wild recombinant individuals - to investigate one trait associated with Mimulus guttatus (yellow monkeyflower) adaptation to geothermal soils in Yellowstone National Park. We mapped a major QTL causing dense leaf trichomes in thermally adapted plants to a <50-kb region of linkage Group 14 (Tr14) previously implicated in trichome divergence between independent M. guttatus populations. A PoolSeq scan of Tr14 region revealed a cluster of six genes, coincident with the inferred QTL peak, with high allele frequency differences sufficient to explain observed phenotypic differentiation. One of these, the R2R3 MYB transcription factor Migut.N02661, is a plausible functional candidate and was also strongly associated (r2 = 0.27) with trichome phenotype in analyses of wild-collected admixed individuals. Although functional analyses will be necessary to definitively link molecular variants in Tr14 with trichome divergence, our analyses are a major step in that direction. They point to a simple, and parallel, genetic basis for one axis of Mimulus guttatus adaptation to an extreme habitat, suggest a broadly conserved genetic basis for trichome variation across flowering plants and pave the way for further investigations of this challenging case of microgeographic incipient speciation.
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Affiliation(s)
- Margaret F Hendrick
- Division of Biological Sciences, University of Montana, 32 Campus Dr., Missoula, MT, 59812, USA.,Department of Earth and Environment, Boston University, 685 Commonwealth Ave., Boston, MA, 02215, USA
| | - Findley R Finseth
- Division of Biological Sciences, University of Montana, 32 Campus Dr., Missoula, MT, 59812, USA
| | - Minna E Mathiasson
- School of Biology and Ecology, University of Maine, 5751 Murray Hall, Orono, ME, 04469, USA
| | - Kristen A Palmer
- Department of Biology, Wheaton College, 26 E. Main St., Norton, MA, 02766, USA
| | - Emma M Broder
- Biology Department, Wesleyan University, 45 Wyllys Ave., Middletown, CT, 06259, USA
| | - Peter Breigenzer
- Division of Biological Sciences, University of Montana, 32 Campus Dr., Missoula, MT, 59812, USA
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, 32 Campus Dr., Missoula, MT, 59812, USA
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28
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Stuglik MT, Babik W. Genomic heterogeneity of historical gene flow between two species of newts inferred from transcriptome data. Ecol Evol 2016; 6:4513-25. [PMID: 27386093 PMCID: PMC4930998 DOI: 10.1002/ece3.2152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 01/31/2023] Open
Abstract
The role of gene flow in species formation is a major unresolved issue in speciation biology. Progress in this area requires information on the long-term patterns of gene flow between diverging species. Here, we used thousands of single-nucleotide polymorphisms derived from transcriptome resequencing and a method modeling the joint frequency spectrum of these polymorphisms to reconstruct patterns of historical gene flow between two Lissotriton newts: L. vulgaris (Lv) and L. montandoni (Lm). We tested several models of divergence including complete isolation and various scenarios of historical gene flow. The model of secondary contact received the highest support. According to this model, the species split from their common ancestor ca. 5.5 million years (MY) ago, evolved in isolation for ca. 2 MY, and have been exchanging genes for the last 3.5 MY Demographic changes have been inferred in both species, with the current effective population size of ca. 0.7 million in Lv and 0.2 million in Lm. The postdivergence gene flow resulted in two-directional introgression which affected the genomes of both species, but was more pronounced from Lv to Lm. Interestingly, we found evidence for genomic heterogeneity of interspecific gene flow. This study demonstrates the complexity of long-term gene flow between distinct but incompletely reproductively isolated taxa which divergence was initiated millions of years ago.
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Affiliation(s)
- Michał T. Stuglik
- Institute of Environmental SciencesJagiellonian UniversityGronostajowa 730387KrakowPoland
| | - Wiesław Babik
- Institute of Environmental SciencesJagiellonian UniversityGronostajowa 730387KrakowPoland
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29
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Prabh N, Rödelsperger C. Are orphan genes protein-coding, prediction artifacts, or non-coding RNAs? BMC Bioinformatics 2016; 17:226. [PMID: 27245157 PMCID: PMC4888513 DOI: 10.1186/s12859-016-1102-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/24/2016] [Indexed: 12/26/2022] Open
Abstract
Background Current genome sequencing projects reveal substantial numbers of taxonomically restricted, so called orphan genes that lack homology with genes from other evolutionary lineages. However, it is not clear to what extent orphan genes are real, genomic artifacts, or represent non-coding RNAs. Results Here, we use a simple set of assumptions to test the nature of orphan genes. First, a sequence that is transcribed is considered a real biological entity. Second, every sequence that is supported by proteome data or shows a depletion of non-synonymous substitutions is a protein-coding gene. Using genomic, transcriptomic and proteomic data for the nematode Pristionchus pacificus, we show that between 4129–7997 (42–81 %) of predicted orphan genes are expressed and 3818–7545 (39–76 %) of orphan genes are under negative selection. In three cases that exhibited strong evolutionary constraint but lacked expression evidence in 14 RNA-seq samples, we could experimentally validate the predicted gene structures. Comparing different data sets to infer selection on orphan gene clusters, we find that the presence of a closely related genome provides the most powerful resource to robustly identify evidence of negative selection. However, even in the absence of other genomic data, the availability of paralogous sequences was enough to show negative selection in 8–10 % of orphan genes. Conclusions Our study shows that the great majority of previously identified orphan genes in P. pacificus are indeed protein-coding genes. Even though this work represents a case study on a single species, our approach can be transferred to genomic data of other non-model organisms in order to ascertain the protein-coding nature of orphan genes.
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Affiliation(s)
- Neel Prabh
- Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany
| | - Christian Rödelsperger
- Department for Evolutionary Biology, Max-Planck-Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany.
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30
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Brennan AC, Hiscock SJ, Abbott RJ. Genomic architecture of phenotypic divergence between two hybridizing plant species along an elevational gradient. AOB PLANTS 2016; 8:plw022. [PMID: 27083198 PMCID: PMC4887755 DOI: 10.1093/aobpla/plw022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 03/19/2016] [Indexed: 05/03/2023]
Abstract
Knowledge of the genetic basis of phenotypic divergence between species and how such divergence is caused and maintained is crucial to an understanding of speciation and the generation of biodiversity. The hybrid zone between Senecio aethnensis and S. chrysanthemifolius on Mount Etna, Sicily, provides a well-studied example of species divergence in response to conditions at different elevations, despite hybridization and gene flow. Here, we investigate the genetic architecture of divergence between these two species using a combination of quantitative trait locus (QTL) mapping and genetic differentiation measures based on genetic marker analysis. A QTL architecture characterized by physical QTL clustering, epistatic interactions between QTLs, and pleiotropy was identified, and is consistent with the presence of divergent QTL complexes resistant to gene flow. A role for divergent selection between species was indicated by significant negative associations between levels of interspecific genetic differentiation at mapped marker gene loci and map distance from QTLs and hybrid incompatibility loci. Within-species selection contributing to interspecific differentiation was evidenced by negative associations between interspecific genetic differentiation and genetic diversity within species. These results show that the two Senecio species, while subject to gene flow, maintain divergent genomic regions consistent with local selection within species and selection against hybrids between species which, in turn, contribute to the maintenance of their distinct phenotypic differences.
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Affiliation(s)
- Adrian C Brennan
- School of Biology, University of St Andrews, Harold Mitchell Building, St Andrews, Fife KY16 9TH, UK Estación Biológica de Doñana (EBD-CSIC), Avenida Américo Vespucio s/n, 41092 Sevilla, Spain Present address: School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, UK
| | - Simon J Hiscock
- School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
| | - Richard J Abbott
- School of Biology, University of St Andrews, Harold Mitchell Building, St Andrews, Fife KY16 9TH, UK
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31
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Filatov DA, Osborne OG, Papadopulos AST. Demographic history of speciation in a Senecio altitudinal hybrid zone on Mt. Etna. Mol Ecol 2016; 25:2467-81. [PMID: 26994342 DOI: 10.1111/mec.13618] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 02/29/2016] [Accepted: 02/29/2016] [Indexed: 01/16/2023]
Abstract
Hybrid zones typically form as a result of species coming into secondary contact, but can also be established in situ as an ecotonal hybrid zone, a situation which has been reported far less frequently. An altitudinal hybrid zone on Mount Etna between two ragwort species (the low elevation Senecio chrysanthemifolius and high elevation S. aethnensis) could potentially represent either of these possibilities. However, a scenario of secondary contact vs. speciation with gene flow has not been explicitly tested. Here, we test these alternatives and demonstrate that the data do not support secondary contact. Furthermore, we report that the previous analyses of speciation history of these species were based on admixed populations, which has led to inflated estimates of ongoing, interspecific gene flow. Our new analyses, based on 'pure' S. aethnensis and S. chrysanthemifolius populations, reveal gene exchange of less than one effective migrant per generation, a level low enough to allow the species to accumulate neutral, genomewide differences. Overall, our results are consistent with a scenario of speciation with gene flow and a divergence time which coincides with the rise of Mt. Etna to altitudes above 2000 m (~150 KY). Further work to quantify the role of adaptation to contrasting environments of high and low altitudes will be needed to support the scenario of recent ecological speciation in this system.
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Affiliation(s)
- Dmitry A Filatov
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - Owen G Osborne
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - Alexander S T Papadopulos
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.,Royal Botanic Gardens, Kew, Richmond, TW9 3AB, UK
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32
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Uebbing S, Künstner A, Mäkinen H, Backström N, Bolivar P, Burri R, Dutoit L, Mugal CF, Nater A, Aken B, Flicek P, Martin FJ, Searle SMJ, Ellegren H. Divergence in gene expression within and between two closely related flycatcher species. Mol Ecol 2016; 25:2015-28. [PMID: 26928872 PMCID: PMC4879514 DOI: 10.1111/mec.13596] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/15/2016] [Accepted: 02/17/2016] [Indexed: 12/12/2022]
Abstract
Relatively little is known about the character of gene expression evolution as species diverge. It is for instance unclear if gene expression generally evolves in a clock‐like manner (by stabilizing selection or neutral evolution) or if there are frequent episodes of directional selection. To gain insights into the evolutionary divergence of gene expression, we sequenced and compared the transcriptomes of multiple organs from population samples of collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca), two species which diverged less than one million years ago. Ordination analysis separated samples by organ rather than by species. Organs differed in their degrees of expression variance within species and expression divergence between species. Variance was negatively correlated with expression breadth and protein interactivity, suggesting that pleiotropic constraints reduce gene expression variance within species. Variance was correlated with between‐species divergence, consistent with a pattern expected from stabilizing selection and neutral evolution. Using an expression PST approach, we identified genes differentially expressed between species and found 16 genes uniquely expressed in one of the species. For one of these, DPP7, uniquely expressed in collared flycatcher, the absence of expression in pied flycatcher could be associated with a ≈20‐kb deletion including 11 of 13 exons. This study of a young vertebrate speciation model system expands our knowledge of how gene expression evolves as natural populations become reproductively isolated.
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Affiliation(s)
- Severin Uebbing
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Axel Künstner
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Hannu Mäkinen
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Niclas Backström
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Paulina Bolivar
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Reto Burri
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Ludovic Dutoit
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Carina F Mugal
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Alexander Nater
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Bronwen Aken
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Paul Flicek
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Fergal J Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Stephen M J Searle
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Hans Ellegren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
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33
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Rosenzweig BK, Pease JB, Besansky NJ, Hahn MW. Powerful methods for detecting introgressed regions from population genomic data. Mol Ecol 2016; 25:2387-97. [PMID: 26945783 DOI: 10.1111/mec.13610] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/22/2016] [Indexed: 12/31/2022]
Abstract
Understanding the types and functions of genes that are able to cross species boundaries-and those that are not-is an important step in understanding the forces maintaining species as largely independent lineages across the remainder of the genome. With large next-generation sequencing data sets we are now able to ask whether introgression has occurred across the genome, and multiple methods have been proposed to detect the signature of such events. Here, we introduce a new summary statistic that can be used to test for introgression, RNDmin , that makes use of the minimum pairwise sequence distance between two population samples relative to divergence to an outgroup. We find that our method offers a modest increase in power over other, related tests, but that all such tests have high power to detect introgressed loci when migration is recent and strong. RNDmin is robust to variation in the mutation rate, and remains reliable even when estimates of the divergence time between sister species are inaccurate. We apply RNDmin to population genomic data from the African mosquitoes Anopheles quadriannulatus and A. arabiensis, identifying three novel candidate regions for introgression. Interestingly, one of the introgressed loci is on the X chromosome, but outside of an inversion separating these two species. Our results suggest that significant, but rare, sharing of alleles is occurring between species that diverged more than 1 million years ago, and that application of these methods to additional systems are likely to reveal similar results.
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Affiliation(s)
- Benjamin K Rosenzweig
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47405, USA
| | - James B Pease
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47405, USA.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Nora J Besansky
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Matthew W Hahn
- School of Informatics and Computing, Indiana University, Bloomington, IN, 47405, USA.,Department of Biology, Indiana University, Bloomington, IN, 47405, USA
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34
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Marques DA, Lucek K, Meier JI, Mwaiko S, Wagner CE, Excoffier L, Seehausen O. Genomics of Rapid Incipient Speciation in Sympatric Threespine Stickleback. PLoS Genet 2016; 12:e1005887. [PMID: 26925837 PMCID: PMC4771382 DOI: 10.1371/journal.pgen.1005887] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 01/29/2016] [Indexed: 01/18/2023] Open
Abstract
Ecological speciation is the process by which reproductively isolated populations emerge as a consequence of divergent natural or ecologically-mediated sexual selection. Most genomic studies of ecological speciation have investigated allopatric populations, making it difficult to infer reproductive isolation. The few studies on sympatric ecotypes have focused on advanced stages of the speciation process after thousands of generations of divergence. As a consequence, we still do not know what genomic signatures of the early onset of ecological speciation look like. Here, we examined genomic differentiation among migratory lake and resident stream ecotypes of threespine stickleback reproducing in sympatry in one stream, and in parapatry in another stream. Importantly, these ecotypes started diverging less than 150 years ago. We obtained 34,756 SNPs with restriction-site associated DNA sequencing and identified genomic islands of differentiation using a Hidden Markov Model approach. Consistent with incipient ecological speciation, we found significant genomic differentiation between ecotypes both in sympatry and parapatry. Of 19 islands of differentiation resisting gene flow in sympatry, all were also differentiated in parapatry and were thus likely driven by divergent selection among habitats. These islands clustered in quantitative trait loci controlling divergent traits among the ecotypes, many of them concentrated in one region with low to intermediate recombination. Our findings suggest that adaptive genomic differentiation at many genetic loci can arise and persist in sympatry at the very early stage of ecotype divergence, and that the genomic architecture of adaptation may facilitate this.
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Affiliation(s)
- David A. Marques
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- * E-mail:
| | - Kay Lucek
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Department of Animal and Plant Science, University of Sheffield, Sheffield, United Kingdom
| | - Joana I. Meier
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Salome Mwaiko
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Catherine E. Wagner
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
- Biodiversity Institute, University of Wyoming, Wyoming, United States of America
| | - Laurent Excoffier
- Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Ole Seehausen
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Department of Fish Ecology and Evolution, Centre of Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
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Ferchaud AL, Hansen MM. The impact of selection, gene flow and demographic history on heterogeneous genomic divergence: three-spine sticklebacks in divergent environments. Mol Ecol 2015; 25:238-59. [DOI: 10.1111/mec.13399] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 09/15/2015] [Accepted: 09/21/2015] [Indexed: 01/14/2023]
Affiliation(s)
- Anne-Laure Ferchaud
- Department of Bioscience; Aarhus University; Ny Munkegade 114-116 DK-8000 Aarhus C Denmark
| | - Michael M. Hansen
- Department of Bioscience; Aarhus University; Ny Munkegade 114-116 DK-8000 Aarhus C Denmark
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Chapman MA, Hiscock SJ, Filatov DA. The genomic bases of morphological divergence and reproductive isolation driven by ecological speciation in Senecio (Asteraceae). J Evol Biol 2015; 29:98-113. [PMID: 26414668 DOI: 10.1111/jeb.12765] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/18/2015] [Accepted: 09/18/2015] [Indexed: 12/18/2022]
Abstract
Ecological speciation, driven by adaptation to contrasting environments, provides an attractive opportunity to study the formation of distinct species, and the role of selection and genomic divergence in this process. Here, we focus on a particularly clear-cut case of ecological speciation to reveal the genomic bases of reproductive isolation and morphological differences between closely related Senecio species, whose recent divergence within the last ~200,000 years was likely driven by the uplift of Mt. Etna (Sicily). These species form a hybrid zone, yet remain morphologically and ecologically distinct, despite active gene exchange. Here, we report a high-density genetic map of the Senecio genome and map hybrid breakdown to one large and several small quantitative trait loci (QTL). Loci under diversifying selection cluster in three 5 cM regions which are characterized by a significant increase in relative (F(ST)), but not absolute (d(XY)), interspecific differentiation. They also correspond to some of the regions of greatest marker density, possibly corresponding to 'cold-spots' of recombination, such as centromeres or chromosomal inversions. Morphological QTL for leaf and floral traits overlap these clusters. We also detected three genomic regions with significant transmission ratio distortion (TRD), possibly indicating accumulation of intrinsic genetic incompatibilities between these recently diverged species. One of the TRD regions overlapped with a cluster of high species differentiation, and another overlaps the large QTL for hybrid breakdown, indicating that divergence of these species may have occurred due to a complex interplay of ecological divergence and accumulation of intrinsic genetic incompatibilities.
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Affiliation(s)
- M A Chapman
- Department of Plant Sciences, University of Oxford, Oxford, UK.,Centre for Biological Sciences, University of Southampton, Southampton, UK
| | - S J Hiscock
- University of Oxford Botanic Garden, Rose Lane, Oxford, UK
| | - D A Filatov
- Department of Plant Sciences, University of Oxford, Oxford, UK
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Gaither MR, Bernal MA, Coleman RR, Bowen BW, Jones SA, Simison WB, Rocha LA. Genomic signatures of geographic isolation and natural selection in coral reef fishes. Mol Ecol 2015; 24:1543-57. [PMID: 25753379 DOI: 10.1111/mec.13129] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 02/20/2015] [Accepted: 02/24/2015] [Indexed: 01/17/2023]
Abstract
The drivers of speciation remain among the most controversial topics in evolutionary biology. Initially, Darwin emphasized natural selection as a primary mechanism of speciation, but the architects of the modern synthesis largely abandoned that view in favour of divergence by geographic isolation. The balance between selection and isolation is still at the forefront of the evolutionary debate, especially for the world's tropical oceans where biodiversity is high, but isolating barriers are few. Here, we identify the drivers of speciation in Pacific reef fishes of the genus Acanthurus by comparative genome scans of two peripheral populations that split from a large Central-West Pacific lineage at roughly the same time. Mitochondrial sequences indicate that populations in the Hawaiian Archipelago and the Marquesas Islands became isolated approximately 0.5 Ma. The Hawaiian lineage is morphologically indistinguishable from the widespread Pacific form, but the Marquesan form is recognized as a distinct species that occupies an unusual tropical ecosystem characterized by upwelling, turbidity, temperature fluctuations, algal blooms and little coral cover. An analysis of 3737 SNPs reveals a strong signal of selection at the Marquesas, with 59 loci under disruptive selection including an opsin Rh2 locus. While both the Hawaiian and Marquesan populations indicate signals of drift, the former shows a weak signal of selection that is comparable with populations in the Central-West Pacific. This contrast between closely related lineages reveals one population diverging due primarily to geographic isolation and genetic drift, and the other achieving taxonomic species status under the influence of selection.
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Affiliation(s)
- Michelle R Gaither
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, DH1 3LE, UK; Section of Ichthyology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA, 94118, USA
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Ravinet M, Hynes R, Poole R, Cross TF, McGinnity P, Harrod C, Prodöhl PA. Where the lake meets the sea: strong reproductive isolation is associated with adaptive divergence between lake resident and anadromous three-spined sticklebacks. PLoS One 2015; 10:e0122825. [PMID: 25874617 PMCID: PMC4397041 DOI: 10.1371/journal.pone.0122825] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/14/2015] [Indexed: 11/28/2022] Open
Abstract
Contact zones between divergent forms of the same species are often characterised by high levels of phenotypic diversity over small geographic distances. What processes are involved in generating such high phenotypic diversity? One possibility is that introgression and recombination between divergent forms in contact zones results in greater phenotypic and genetic polymorphism. Alternatively, strong reproductive isolation between forms may maintain distinct phenotypes, preventing homogenisation by gene flow. Contact zones between divergent freshwater-resident and anadromous stickleback (Gasterosteus aculeatus L.) forms are numerous and common throughout the species distribution, offering an opportunity to examine these contrasting hypotheses in greater detail. This study reports on an interesting new contact zone located in a tidally influenced lake catchment in western Ireland, characterised by high polymorphism for lateral plate phenotypes. Using neutral and QTL-linked microsatellite markers, we tested whether the high diversity observed in this contact zone arose as a result of introgression or reproductive isolation between divergent forms: we found strong support for the latter hypothesis. Three phenotypic and genetic clusters were identified, consistent with two divergent resident forms and a distinct anadromous completely plated population that migrates in and out of the system. Given the strong neutral differentiation detected between all three morphotypes (mean FST = 0.12), we hypothesised that divergent selection between forms maintains reproductive isolation. We found a correlation between neutral genetic and adaptive genetic differentiation that support this. While strong associations between QTL linked markers and phenotypes were also observed in this wild population, our results support the suggestion that such associations may be more complex in some Atlantic populations compared to those in the Pacific. These findings provide an important foundation for future work investigating the dynamics of gene flow and adaptive divergence in this newly discovered stickleback contact zone.
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Affiliation(s)
- Mark Ravinet
- School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Rosaleen Hynes
- School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Russell Poole
- Marine Institute, Furnace, Newport, County Mayo, Ireland
| | - Tom F. Cross
- Aquaculture, Fisheries and Development Centre, School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
| | - Phil McGinnity
- Aquaculture, Fisheries and Development Centre, School of Biological, Earth & Environmental Sciences, University College Cork, Cork, Ireland
| | - Chris Harrod
- School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Paulo A. Prodöhl
- School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- * E-mail:
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Fraser BA, Künstner A, Reznick DN, Dreyer C, Weigel D. Population genomics of natural and experimental populations of guppies (Poecilia reticulata). Mol Ecol 2015; 24:389-408. [PMID: 25444454 DOI: 10.1111/mec.13022] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 12/30/2022]
Abstract
Convergent evolution represents one of the best lines of evidence for adaptation, but few cases of phenotypic convergence are understood at the genetic level. Guppies inhabiting the Northern Mountain Range of Trinidad provide a classic example of phenotypic convergent evolution, where adaptation to low or high predation environments has been found for a variety of traits. A major advantage of this system is the possibility of long-term experimental studies in nature, including transplantation from high to low predation sites. We used genome scans of guppies from three natural high and low predation populations and from two experimentally established populations and their sources to examine whether phenotypic convergent evolution leaves footprints at the genome level. We used population-genetic modelling approaches to reconstruct the demographic history and migration among sampled populations. Naturally colonized low predation populations had signatures of increased effective population size since colonization, while introduction populations had signatures of decreased effective population size. Only a small number of regions across the genome had signatures of selection in all natural populations. However, the two experimental populations shared many genomic regions under apparent selection, more than expected by chance. This overlap coupled with a population decrease since introduction provides evidence for convergent selection occurring in the two introduced populations. The lack of genetic convergence in the natural populations suggests that convergent evolution is lacking in these populations or that the effects of selection become difficult to detect after a long-time period.
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Affiliation(s)
- Bonnie A Fraser
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany
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Abstract
The extraordinary species richness of freshwater fishes has attracted much research on mechanisms and modes of speciation. We here review research on speciation in freshwater fishes in light of speciation theory, and place this in a context of broad-scale diversity patterns in freshwater fishes. We discuss several major repeated themes in freshwater fish speciation and the speciation mechanisms they are frequently associated with. These include transitions between marine and freshwater habitats, transitions between discrete freshwater habitats, and ecological transitions within habitats, as well as speciation without distinct niche shifts. Major research directions in the years to come include understanding the transition from extrinsic environment-dependent to intrinsic reproductive isolation and its influences on species persistence and understanding the extrinsic and intrinsic constraints to speciation and how these relate to broad-scale diversification patterns through time.
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Affiliation(s)
- Ole Seehausen
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
- Department of Fish Ecology and Evolution, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Center of Ecology, Evolution and Biogeochemistry, 6047 Kastanienbaum, Switzerland
| | - Catherine E. Wagner
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, CH-3012 Bern, Switzerland
- Department of Fish Ecology and Evolution, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Center of Ecology, Evolution and Biogeochemistry, 6047 Kastanienbaum, Switzerland
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41
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Lundsgaard-Hansen B, Matthews B, Seehausen O. Ecological speciation and phenotypic plasticity affect ecosystems. Ecology 2014. [DOI: 10.1890/13-2338.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Westram AM, Galindo J, Alm Rosenblad M, Grahame JW, Panova M, Butlin RK. Do the same genes underlie parallel phenotypic divergence in different Littorina saxatilis populations? Mol Ecol 2014; 23:4603-16. [PMID: 25113130 PMCID: PMC4285301 DOI: 10.1111/mec.12883] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/24/2014] [Accepted: 07/29/2014] [Indexed: 02/03/2023]
Abstract
Parallel patterns of adaptive divergence and speciation are cited as powerful evidence for the role of selection driving these processes. However, it is often not clear whether parallel phenotypic divergence is underlain by parallel genetic changes. Here, we asked about the genetic basis of parallel divergence in the marine snail Littorina saxatilis, which has repeatedly evolved coexisting ecotypes adapted to either crab predation or wave action. We sequenced the transcriptome of snails of both ecotypes from three distant geographical locations (Spain, Sweden and United Kingdom) and mapped the reads to the L. saxatilis reference genome. We identified genomic regions potentially under divergent selection between ecotypes within each country, using an outlier approach based on F(ST) values calculated per locus. In line with previous studies indicating that gene reuse is generally common, we expected to find extensive sharing of outlier loci due to recent shared ancestry and gene flow between at least two of the locations in our study system. Contrary to our expectations, we found that most outliers were country specific, suggesting that much of the genetic basis of divergence is not shared among locations. However, we did find that more outliers were shared than expected by chance and that differentiation of shared outliers is often generated by the same SNPs. We discuss two mechanisms potentially explaining the limited amount of sharing we observed. First, a polygenic basis of divergent traits might allow for multiple distinct molecular mechanisms generating the same phenotypic patterns. Second, additional, location-specific axes of selection that we did not focus on in this study may produce distinct patterns of genetic divergence within each site.
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Affiliation(s)
- A M Westram
- Animal and Plant Sciences, University of Sheffield, Sheffield, S102TN, UK
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Feder JL, Nosil P, Flaxman SM. Assessing when chromosomal rearrangements affect the dynamics of speciation: implications from computer simulations. Front Genet 2014; 5:295. [PMID: 25206365 PMCID: PMC4144205 DOI: 10.3389/fgene.2014.00295] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 08/08/2014] [Indexed: 12/03/2022] Open
Abstract
Many hypotheses have been put forth to explain the origin and spread of inversions, and their significance for speciation. Several recent genic models have proposed that inversions promote speciation with gene flow due to the adaptive significance of the genes contained within them and because of the effects inversions have on suppressing recombination. However, the consequences of inversions for the dynamics of genome wide divergence across the speciation continuum remain unclear, an issue we examine here. We review a framework for the genomics of speciation involving the congealing of the genome into alternate adaptive states representing species (“genome wide congealing”). We then place inversions in this context as examples of how genetic hitchhiking can potentially hasten genome wide congealing. Specifically, we use simulation models to (i) examine the conditions under which inversions may speed genome congealing and (ii) quantify predicted magnitudes of these effects. Effects of inversions on promoting speciation were most common and pronounced when inversions were initially fixed between populations before secondary contact and adaptation involved many genes with small fitness effects. Further work is required on the role of underdominance and epistasis between a few loci of major effect within inversions. The results highlight five important aspects of the roles of inversions in speciation: (i) the geographic context of the origins and spread of inversions, (ii) the conditions under which inversions can facilitate divergence, (iii) the magnitude of that facilitation, (iv) the extent to which the buildup of divergence is likely to be biased within vs. outside of inversions, and (v) the dynamics of the appearance and disappearance of exceptional divergence within inversions. We conclude by discussing the empirical challenges in showing that inversions play a central role in facilitating speciation with gene flow.
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Affiliation(s)
- Jeffrey L Feder
- Department of Biological Sciences, University of Notre Dame Notre Dame, IN, USA
| | - Patrik Nosil
- Department of Animal and Plant Sciences, University of Sheffield Sheffield, UK
| | - Samuel M Flaxman
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, CO, USA
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Feder JL, Nosil P, Wacholder AC, Egan SP, Berlocher SH, Flaxman SM. Genome-Wide Congealing and Rapid Transitions across the Speciation Continuum during Speciation with Gene Flow. J Hered 2014; 105 Suppl 1:810-20. [DOI: 10.1093/jhered/esu038] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Panova M, Johansson T, Canbäck B, Bentzer J, Rosenblad MA, Johannesson K, Tunlid A, André C. Species and gene divergence in Littorina snails detected by array comparative genomic hybridization. BMC Genomics 2014; 15:687. [PMID: 25135785 PMCID: PMC4148934 DOI: 10.1186/1471-2164-15-687] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 08/11/2014] [Indexed: 12/11/2022] Open
Abstract
Background Array comparative genomic hybridization (aCGH) is commonly used to screen different types of genetic variation in humans and model species. Here, we performed aCGH using an oligonucleotide gene-expression array for a non-model species, the intertidal snail Littorina saxatilis. First, we tested what types of genetic variation can be detected by this method using direct re-sequencing and comparison to the Littorina genome draft. Secondly, we performed a genome-wide comparison of four closely related Littorina species: L. fabalis, L. compressa, L. arcana and L. saxatilis and of populations of L. saxatilis found in Spain, Britain and Sweden. Finally, we tested whether we could identify genetic variation underlying “Crab” and “Wave” ecotypes of L. saxatilis. Results We could reliably detect copy number variations, deletions and high sequence divergence (i.e. above 3%), but not single nucleotide polymorphisms. The overall hybridization pattern and number of significantly diverged genes were in close agreement with earlier phylogenetic reconstructions based on single genes. The trichotomy of L. arcana, L. compressa and L. saxatilis could not be resolved and we argue that these divergence events have occurred recently and very close in time. We found evidence for high levels of segmental duplication in the Littorina genome (10% of the transcripts represented on the array and up to 23% of the analyzed genomic fragments); duplicated genes and regions were mostly the same in all analyzed species. Finally, this method discriminated geographically distant populations of L. saxatilis, but we did not detect any significant genome divergence associated with ecotypes of L. saxatilis. Conclusions The present study provides new information on the sensitivity and the potential use of oligonucleotide arrays for genotyping of non-model organisms. Applying this method to Littorina species yields insights into genome evolution following the recent species radiation and supports earlier single-gene based phylogenies. Genetic differentiation of L. saxatilis ecotypes was not detected in this study, despite pronounced innate phenotypic differences. The reason may be that these differences are due to single-nucleotide polymorphisms. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-687) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marina Panova
- Department of Biological and Environmental Sciences - Tjärnö, Gothenburg University, Gothenburg, Sweden.
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Ruegg K, Anderson EC, Boone J, Pouls J, Smith TB. A role for migration-linked genes and genomic islands in divergence of a songbird. Mol Ecol 2014; 23:4757-69. [PMID: 24954641 DOI: 10.1111/mec.12842] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 06/13/2014] [Accepted: 06/18/2014] [Indexed: 02/02/2023]
Abstract
Next-generation sequencing has made it possible to begin asking questions about the process of divergence at the level of the genome. For example, recently, there has been a debate around the role of 'genomic islands of divergence' (i.e. blocks of outlier loci) in facilitating the process of speciation-with-gene-flow. The Swainson's thrush, Catharus ustulatus, is a migratory songbird with two genetically distinct subspecies that differ in a number of traits known to be involved in reproductive isolation in birds (plumage coloration, song and migratory behaviour), despite contemporary gene flow along a secondary contact zone. Here, we use RAD-PE sequencing to test emerging hypotheses about the process of divergence at the level of the genome and identify genes and gene regions involved in differentiation in this migratory songbird. Our analyses revealed distinct genomic islands on 15 of the 23 chromosomes and an accelerated rate of divergence on the Z chromosome, one of the avian sex chromosomes. Further, an analysis of loci linked to traits known to be involved in reproductive isolation in songbirds showed that genes linked to migration are significantly more differentiated than expected by chance, but that these genes lie primarily outside the genomic islands. Overall, our analysis supports the idea that genes linked to migration play an important role in divergence in migratory songbirds, but we find no compelling evidence that the observed genomic islands are facilitating adaptive divergence in migratory behaviour.
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Affiliation(s)
- Kristen Ruegg
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, La Kretz Hall, Suite 300, 619 Charles E. Young Dr. East, Los Angeles, CA, 90095, USA; Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, 95060, USA
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48
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Faria R, Renaut S, Galindo J, Pinho C, Melo-Ferreira J, Melo M, Jones F, Salzburger W, Schluter D, Butlin R. Advances in Ecological Speciation: an integrative approach. Mol Ecol 2014; 23:513-21. [DOI: 10.1111/mec.12616] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 11/28/2013] [Accepted: 11/30/2013] [Indexed: 12/19/2022]
Affiliation(s)
- Rui Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
- IBE, Institute of Evolutionary Biology (UPF-CSIC); Universitat Pompeu Fabra. PRBB; Av. Doctor Aiguader N88 08003 Barcelona Spain
| | - Sebastien Renaut
- Department of Botany; Biodiversity Research Centre; University of British Columbia; Vancouver British Columbia Canada V6T 1Z4
| | - Juan Galindo
- Departamento de Bioquímica, Xenética e Inmunoloxía; Facultade de Bioloxía; Universidade de Vigo; Campus Universitario 36310 Vigo Spain
| | - Catarina Pinho
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - José Melo-Ferreira
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - Martim Melo
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBio; Laboratório Associado; Universidade do Porto. Campus Agrário de Vairão; 4485-661 Vairão Portugal
| | - Felicity Jones
- Friedrich Miescher Laboratory of the Max Planck Society; Tuebingen 72070 Germany
| | - Walter Salzburger
- Zoological Institute; University of Basel; Vesalgasse 1 4051 Basel Switzerland
| | - Dolph Schluter
- Department of Zoology; Biodiversity Research Centre; University of British Columbia; Vancouver British Columbia Canada V6T 1Z4
| | - Roger Butlin
- Animal and Plant Sciences; University of Sheffield; Sheffield S10 2TN UK
- Sven Lovén Centre - Tjärnö; University of Gothenburg; S-452 96 Strömstad Sweden
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49
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Powell THQ, Forbes AA, Hood GR, Feder JL. Ecological adaptation and reproductive isolation in sympatry: genetic and phenotypic evidence for native host races ofRhagoletis pomonella. Mol Ecol 2014; 23:688-704. [DOI: 10.1111/mec.12635] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 12/04/2013] [Accepted: 12/11/2013] [Indexed: 01/08/2023]
Affiliation(s)
- Thomas H. Q. Powell
- Department of Biological Sciences; University of Notre Dame; Galvin Life Sciences Building Notre Dame IN 46556 USA
| | - Andrew A. Forbes
- Department of Biological Sciences; University of Notre Dame; Galvin Life Sciences Building Notre Dame IN 46556 USA
| | - Glen R. Hood
- Department of Biological Sciences; University of Notre Dame; Galvin Life Sciences Building Notre Dame IN 46556 USA
| | - Jeffrey L. Feder
- Department of Biological Sciences; University of Notre Dame; Galvin Life Sciences Building Notre Dame IN 46556 USA
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50
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Larson WA, Seeb LW, Everett MV, Waples RK, Templin WD, Seeb JE. Genotyping by sequencing resolves shallow population structure to inform conservation of Chinook salmon (Oncorhynchus tshawytscha). Evol Appl 2014; 7:355-69. [PMID: 24665338 PMCID: PMC3962296 DOI: 10.1111/eva.12128] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 10/02/2013] [Indexed: 12/14/2022] Open
Abstract
Recent advances in population genomics have made it possible to detect previously unidentified structure, obtain more accurate estimates of demographic parameters, and explore adaptive divergence, potentially revolutionizing the way genetic data are used to manage wild populations. Here, we identified 10 944 single-nucleotide polymorphisms using restriction-site-associated DNA (RAD) sequencing to explore population structure, demography, and adaptive divergence in five populations of Chinook salmon (Oncorhynchus tshawytscha) from western Alaska. Patterns of population structure were similar to those of past studies, but our ability to assign individuals back to their region of origin was greatly improved (>90% accuracy for all populations). We also calculated effective size with and without removing physically linked loci identified from a linkage map, a novel method for nonmodel organisms. Estimates of effective size were generally above 1000 and were biased downward when physically linked loci were not removed. Outlier tests based on genetic differentiation identified 733 loci and three genomic regions under putative selection. These markers and genomic regions are excellent candidates for future research and can be used to create high-resolution panels for genetic monitoring and population assignment. This work demonstrates the utility of genomic data to inform conservation in highly exploited species with shallow population structure.
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Affiliation(s)
- Wesley A Larson
- School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA
| | - Lisa W Seeb
- School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA
| | - Meredith V Everett
- School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA
| | - Ryan K Waples
- School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA
| | - William D Templin
- Gene Conservation Laboratory, Alaska Department of Fish and Game Anchorage, AK, USA
| | - James E Seeb
- School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA
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