1
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White OW, Reyes-Betancort A, Carine MA, Chapman MA. Comparative transcriptomics and gene expression divergence associated with homoploid hybrid speciation in Argyranthemum. G3 (BETHESDA, MD.) 2023; 13:jkad158. [PMID: 37477910 PMCID: PMC10542503 DOI: 10.1093/g3journal/jkad158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 04/21/2023] [Accepted: 06/28/2023] [Indexed: 07/22/2023]
Abstract
Ecological isolation is increasingly thought to play an important role in speciation, especially for the origin and reproductive isolation of homoploid hybrid species. However, the extent to which divergent and/or transgressive gene expression changes are involved in speciation is not well studied. In this study, we employ comparative transcriptomics to investigate gene expression changes associated with the origin and evolution of two homoploid hybrid plant species, Argyranthemum sundingii and A. lemsii (Asteraceae). As there is no standard methodology for comparative transcriptomics, we examined five different pipelines for data assembly and analysing gene expression across the four species (two hybrid and two parental). We note biases and problems with all pipelines, and the approach used affected the biological interpretation of the data. Using the approach that we found to be optimal, we identify transcripts showing DE between the parental taxa and between the homoploid hybrid species and their parents; in several cases, putative functions of these DE transcripts have a plausible role in ecological adaptation and could be the cause or consequence of ecological speciation. Although independently derived, the homoploid hybrid species have converged on similar expression phenotypes, likely due to adaptation to similar habitats.
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Affiliation(s)
- Oliver W White
- Algae, Fungi and Plants Division, Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | | | - Mark A Carine
- Algae, Fungi and Plants Division, Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Mark A Chapman
- Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
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2
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Bock DG, Cai Z, Elphinstone C, González-Segovia E, Hirabayashi K, Huang K, Keais GL, Kim A, Owens GL, Rieseberg LH. Genomics of plant speciation. PLANT COMMUNICATIONS 2023; 4:100599. [PMID: 37050879 PMCID: PMC10504567 DOI: 10.1016/j.xplc.2023.100599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/21/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Studies of plants have been instrumental for revealing how new species originate. For several decades, botanical research has complemented and, in some cases, challenged concepts on speciation developed via the study of other organisms while also revealing additional ways in which species can form. Now, the ability to sequence genomes at an unprecedented pace and scale has allowed biologists to settle decades-long debates and tackle other emerging challenges in speciation research. Here, we review these recent genome-enabled developments in plant speciation. We discuss complications related to identification of reproductive isolation (RI) loci using analyses of the landscape of genomic divergence and highlight the important role that structural variants have in speciation, as increasingly revealed by new sequencing technologies. Further, we review how genomics has advanced what we know of some routes to new species formation, like hybridization or whole-genome duplication, while casting doubt on others, like population bottlenecks and genetic drift. While genomics can fast-track identification of genes and mutations that confer RI, we emphasize that follow-up molecular and field experiments remain critical. Nonetheless, genomics has clarified the outsized role of ancient variants rather than new mutations, particularly early during speciation. We conclude by highlighting promising avenues of future study. These include expanding what we know so far about the role of epigenetic and structural changes during speciation, broadening the scope and taxonomic breadth of plant speciation genomics studies, and synthesizing information from extensive genomic data that have already been generated by the plant speciation community.
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Affiliation(s)
- Dan G Bock
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Zhe Cai
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Cassandra Elphinstone
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Eric González-Segovia
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | | | - Kaichi Huang
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Graeme L Keais
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Amy Kim
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Gregory L Owens
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.
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3
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Wang D, Sun Y, Lei W, Zhu H, Wang J, Bi H, Feng S, Liu J, Ru D. Backcrossing to different parents produced two distinct hybrid species. Heredity (Edinb) 2023:10.1038/s41437-023-00630-9. [PMID: 37264213 PMCID: PMC10382510 DOI: 10.1038/s41437-023-00630-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 05/23/2023] [Accepted: 05/23/2023] [Indexed: 06/03/2023] Open
Abstract
Repeated homoploid hybrid speciation (HHS) events with the same parental species have rarely been reported. In this study, we used population transcriptome data to test paraphyly and HHS events in the conifer Picea brachytyla. Our analyses revealed non-sister relationships for two lineages of P. brachytyla, with the southern lineage being placed within the re-circumscribed P. likiangensis species complex (PLSC) and P. brachytyla sensu stricto (s.s.) consisted solely of the northern lineage, forming a distinct clade that is paratactic to both the PLSC and P. wilsonii. Our phylogenetic and coalescent analyses suggested that P. brachytyla s.s. arose from HHS between the ancestor of the PLSC before its diversification and P. wilsonii through an intermediate hybrid lineage at an early stage and backcrossing to the ancestral PLSC. Additionally, P. purpurea shares the same parents and an extinct lineage with P. brachytyla s.s. but backcrossing to the other parent, P. wilsonii at a later stage. We reveal the first case that backcrossing to different parents of the same extinct hybrid lineage produced two different hybrid species. Our results highlight the existence of more reticulate evolution during species diversification in the spruce genus and more complex homoploid hybrid events than previously identified.
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Affiliation(s)
- Donglei Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Yongshuai Sun
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Weixiao Lei
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Hui Zhu
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Ji Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Hao Bi
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Shuo Feng
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xi'ning, Qinghai, China
| | - Jianquan Liu
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China.
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, 730000, China.
| | - Dafu Ru
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China.
- State Key Laboratory of Grassland Agro-ecosystem, College of Ecology, Lanzhou University, Lanzhou, 730000, China.
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4
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Li C, Xiao H, Zhang X, Lin H, Elmer KR, Zhao J. Deep genome-wide divergences among species in White Cloud Mountain minnow Tanichthys albonubes (Cypriniformes: Tanichthyidae) complex: Conservation and species management implications. Mol Phylogenet Evol 2023; 182:107734. [PMID: 36804428 DOI: 10.1016/j.ympev.2023.107734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023]
Abstract
Identifying cryptic species is important for the assessments of biodiversity. Further, untangling mechanisms underlying the origins of cryptic species can facilitate our understanding of evolutionary processes. Advancements in genomic approaches for non-model systems have offered unprecedented opportunities to investigate these areas. The White Cloud Mountain minnow (Tanichthys albonubes) is a popular freshwater pet fish worldwide but its wild populations in China are critically endangered. Recent research based on a few molecular markers suggested that this species in fact comprised seven cryptic species, of which six were previously unknown. Here, we tested six of these cryptic species and quantified genomic interspecific divergences between species in the T. albonubes complex by analyzing genome-wide restriction site-associated DNA sequencing (RADseq) data generated from 189 individuals sampled from seven populations (including an outgroup congeneric species, T. micagemmae). We found that six cryptic species previously suggested were well supported by RADseq data. The genetic diversity of each species in the T. albonubes complex was low compared with T. micagemmae and the contemporary effective population sizes (Ne) of each cryptic species were small. Phylogenetic analysis showed seven clades with high support values confirmed with Neighbor-Net trees. The pairwise divergences between species in T. albonubes complex were deep and the highly differentiated loci were evenly distributed across the genome. We proposed that the divergence level of T. albonubes complex is at a late stage of cryptic speciation and lacking gene flow. Our findings provide new insights into cryptic speciation and have important implications for conservation and species management of T. albonubes complex.
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Affiliation(s)
- Chao Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong Provincial Engineering Technology Research Center for Environmentally Friendly Aquaculture, School of Life Sciences, South China Normal University, Guangzhou, China; Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Han Xiao
- Institute of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - Xiuxia Zhang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong Provincial Engineering Technology Research Center for Environmentally Friendly Aquaculture, School of Life Sciences, South China Normal University, Guangzhou, China
| | - Hungdu Lin
- The Affiliated School of National Tainan First Senior High School, Tainan, Taiwan
| | - Kathryn R Elmer
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jun Zhao
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong Provincial Engineering Technology Research Center for Environmentally Friendly Aquaculture, School of Life Sciences, South China Normal University, Guangzhou, China.
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Wong ELY, Nevado B, Hiscock SJ, Filatov DA. Rapid evolution of hybrid breakdown following recent divergence with gene flow in Senecio species on Mount Etna, Sicily. Heredity (Edinb) 2023; 130:40-52. [PMID: 36494489 PMCID: PMC9814926 DOI: 10.1038/s41437-022-00576-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 12/13/2022] Open
Abstract
How do nascent species evolve reproductive isolation during speciation with on-going gene flow? How do hybrid lineages become stabilised hybrid species? While commonly used genomic approaches provide an indirect way to identify species incompatibility factors, synthetic hybrids generated from interspecific crosses allow direct pinpointing of phenotypic traits involved in incompatibilities and the traits that are potentially adaptive in hybrid species. Here we report the analysis of phenotypic variation and hybrid breakdown in crosses between closely-related Senecio aethnensis and S. chrysanthemifolius, and their homoploid hybrid species, S. squalidus. The two former species represent a likely case of recent (<200 ky) speciation with gene flow driven by adaptation to contrasting conditions of high- and low-elevations on Mount Etna, Sicily. As these species form viable and fertile hybrids, it remains unclear whether they have started to evolve reproductive incompatibility. Our analysis represents the first study of phenotypic variation and hybrid breakdown involving multiple Senecio hybrid families. It revealed wide range of variation in multiple traits, including the traits previously unrecorded in synthetic hybrids. Leaf shape, highly distinct between S. aethnensis and S. chrysanthemifolius, was extremely variable in F2 hybrids, but more consistent in S. squalidus. Our study demonstrates that interspecific incompatibilities can evolve rapidly despite on-going gene flow between the species. Further work is necessary to understand the genetic bases of these incompatibilities and their role in speciation with gene flow.
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Affiliation(s)
- Edgar L. Y. Wong
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.507705.0Senckenberg Biodiversity and Climate Research Centre, Frankfurt am Main, Germany
| | - Bruno Nevado
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,grid.9983.b0000 0001 2181 4263Centre for Ecology, Evolution and Environmental Changes, University of Lisbon, Lisbon, Portugal
| | - Simon J. Hiscock
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK ,Oxford Botanic Garden and Arboretum, Oxford, UK
| | - Dmitry A. Filatov
- grid.4991.50000 0004 1936 8948Department of Biology, University of Oxford, Oxford, UK
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Le Provost G, Brachi B, Lesur I, Lalanne C, Labadie K, Aury JM, Da Silva C, Postolache D, Leroy T, Plomion C. Gene expression and genetic divergence in oak species highlight adaptive genes to soil water constraints. PLANT PHYSIOLOGY 2022; 190:2466-2483. [PMID: 36066428 PMCID: PMC9706432 DOI: 10.1093/plphys/kiac420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/13/2022] [Indexed: 06/15/2023]
Abstract
Drought and waterlogging impede tree growth and may even lead to tree death. Oaks, an emblematic group of tree species, have evolved a range of adaptations to cope with these constraints. The two most widely distributed European species, pedunculate (PO; Quercus robur L.) and sessile oak (SO; Quercus petraea Matt. Lieb), have overlapping ranges, but their respective distribution are highly constrained by local soil conditions. These contrasting ecological preferences between two closely related and frequently hybridizing species constitute a powerful model to explore the functional bases of the adaptive responses in oak. We exposed oak seedlings to waterlogging and drought, conditions typically encountered by the two species in their respective habitats, and studied changes in gene expression in roots using RNA-seq. We identified genes that change in expression between treatments differentially depending on species. These "species × environment"-responsive genes revealed adaptive molecular strategies involving adventitious and lateral root formation, aerenchyma formation in PO, and osmoregulation and ABA regulation in SO. With this experimental design, we also identified genes with different expression between species independently of water conditions imposed. Surprisingly, this category included genes with functions consistent with a role in intrinsic reproductive barriers. Finally, we compared our findings with those for a genome scan of species divergence and found that the expressional candidate genes included numerous highly differentiated genetic markers between the two species. By combining transcriptomic analysis, gene annotation, pathway analyses, as well as genome scan for genetic differentiation among species, we were able to highlight loci likely involved in adaptation of the two species to their respective ecological niches.
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Affiliation(s)
| | | | - Isabelle Lesur
- INRAE, Univ. Bordeaux, BIOGECO, Cestas, F-33610, France
- Helix Venture, Mérignac, F-33700, France
| | | | - Karine Labadie
- Genoscope, Institut de Biologie François-Jacob, Commissariat à l'Energie Atomique (CEA), Université Paris-Saclay, Evry, 91057, France
| | - Jean-Marc Aury
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, 91057, France
| | - Corinne Da Silva
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, 91057, France
| | - Dragos Postolache
- National Institute for Research and Development in Forestry “Marin Drăcea”, Cluj Napoca Research Station, Cluj-Napoca, 400202, Romania
| | - Thibault Leroy
- INRAE, Univ. Bordeaux, BIOGECO, Cestas, F-33610, France
- IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Beaucouzé, 49071, France
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7
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An R, Liu J, Zhang J, Yao F, Tian D, Liang F, Li W, Li D, Wang Y, Yan S, Yang Q, Zhang Y, Su X. Risk factors and SCN5A-H558R polymorphism for atrial fibrillation in Tibetans living at different altitudes. Medicine (Baltimore) 2022; 101:e31778. [PMID: 36401443 PMCID: PMC9678620 DOI: 10.1097/md.0000000000031778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Several studies have found associations of genes with atrial fibrillation (AF), including SCN5A-H558R. However, there are limited data of these associations among populations living at different altitudes. We investigated the relationship between the SCN5A-H558R polymorphism and AF in Tibetans living at different altitudes in Qinghai, China. General clinical and genotype data were obtained from 72 patients with AF and 109 non-AF (NAF) individuals at middle altitudes, and from 102 patients with AF and 143 NAF individuals at high altitudes. Multifactor logistic regression was performed to determine associations and AF risk factors. SCN5A-H558R genotypes differed significantly between the AF and NAF groups (P < .0125) and the G allele was an independent AF risk factor (P < .05) at both altitudes, with no significant differences according to altitude (P > .0125). At middle altitudes, age, red blood cell distribution width (RDW-SD), left atrial internal diameter (LAD), and G allele were independent AF risk factors. At high altitudes, age, smoking, hypertension, RDW-SD, free triiodothyronine, LAD, and G allele were independent AF risk factors (P < .05). The G allele of SCN5A-H558R might be an independent risk factor of AF both high and middle altitude, but there are some differences in other clinical risk factors of AF.
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Affiliation(s)
- Renfang An
- Department of Cardiology, Qinghai Provincial People’s Hospital, Xining, China
| | - Jiang Liu
- Department of Cardiac Function, Xi’an No. 03 Hospital, the Affiliated Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Jinwei Zhang
- Department of Cardiology, Nanyang Center Hospital, Nanyang, China
| | - Fengcai Yao
- Department of Cardiology, Qinghai Provincial People’s Hospital, Xining, China
| | - Dekuan Tian
- Department of Cardiology, The First Hospital of Xining City, Xining, China
| | - Fuli Liang
- Department of Cardiology, Qinghai Provincial Hospital of Cardiovascular and Cerebrovascular Diseases, Xining, China
| | - Wenqiang Li
- Department of Cardiology, Qinghai Provincial People’s Hospital, Xining, China
| | - Delian Li
- Graduate School of Qinghai University, Xining, China
| | - Yiqi Wang
- Graduate School of Qinghai University, Xining, China
| | - Sai Yan
- Graduate School of Qinghai University, Xining, China
| | - Qijuan Yang
- Graduate School of Qinghai University, Xining, China
| | - Yajie Zhang
- Graduate School of Qinghai University, Xining, China
| | - Xiaoling Su
- Department of Cardiology, Qinghai Provincial People’s Hospital, Xining, China
- * Correspondence: Xiaoling Su, Department of Cardiology, Qinghai Provincial People’s Hospital, Xining 810001, China (e-mail: )
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8
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Walter GM, Clark J, Cristaudo A, Terranova D, Nevado B, Catara S, Paunov M, Velikova V, Filatov D, Cozzolino S, Hiscock SJ, Bridle JR. Adaptive divergence generates distinct plastic responses in two closely related Senecio species. Evolution 2022; 76:1229-1245. [PMID: 35344205 PMCID: PMC9322604 DOI: 10.1111/evo.14478] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 01/18/2022] [Indexed: 01/22/2023]
Abstract
The evolution of plastic responses to external cues allows species to maintain fitness in response to the environmental variations they regularly experience. However, it remains unclear how plasticity evolves during adaptation. To test whether distinct patterns of plasticity are associated with adaptive divergence, we quantified plasticity for two closely related but ecologically divergent Sicilian daisy species (Senecio, Asteraceae). We sampled 40 representative genotypes of each species from their native range on Mt. Etna and then reciprocally transplanted multiple clones of each genotype into four field sites along an elevational gradient that included the native elevational range of each species, and two intermediate elevations. At each elevation, we quantified survival and measured leaf traits that included investment (specific leaf area), morphology, chlorophyll fluorescence, pigment content, and gene expression. Traits and differentially expressed genes that changed with elevation in one species often showed little changes in the other species, or changed in the opposite direction. As evidence of adaptive divergence, both species performed better at their native site and better than the species from the other habitat. Adaptive divergence is, therefore, associated with the evolution of distinct plastic responses to environmental variation, despite these two species sharing a recent common ancestor.
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Affiliation(s)
- Greg M. Walter
- School of Biological SciencesUniversity of BristolUK,School of Biological SciencesMonash UniversityMelbourneAustralia
| | - James Clark
- School of Biological SciencesUniversity of BristolUK,Department of Plant SciencesUniversity of OxfordOxfordUK
| | - Antonia Cristaudo
- Department of Biological, Geological, and Environmental SciencesUniversity of CataniaCataniaItaly
| | - Delia Terranova
- Department of Biological, Geological, and Environmental SciencesUniversity of CataniaCataniaItaly
| | - Bruno Nevado
- Department of Plant SciencesUniversity of OxfordOxfordUK,Center of Ecology, Evolution, and Environmental ChangesUniversidade de LisboaLisboaPortugal
| | - Stefania Catara
- Department of Biological, Geological, and Environmental SciencesUniversity of CataniaCataniaItaly
| | - Momchil Paunov
- Faculty of BiologySofia University St. Kliment OhridskiSofiaBulgaria
| | - Violeta Velikova
- Bulgarian Academy of Sciences, Institute of Plant Physiology and GeneticsSofiaBulgaria
| | - Dmitry Filatov
- Department of Plant SciencesUniversity of OxfordOxfordUK
| | | | | | - Jon R. Bridle
- School of Biological SciencesUniversity of BristolUK,Department of Genetics, Evolution, and EnvironmentUniversity College LondonLondonUK
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9
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Termignoni-Garcia F, Kirchman JJ, Clark J, Edwards SV. Comparative Population Genomics of Cryptic Speciation and Adaptive Divergence in Bicknell's and Gray-Cheeked Thrushes (Aves: Catharus bicknelli and Catharus minimus). Genome Biol Evol 2022; 14:evab255. [PMID: 34999784 PMCID: PMC8743040 DOI: 10.1093/gbe/evab255] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 02/07/2023] Open
Abstract
Cryptic speciation may occur when reproductive isolation is recent or the accumulation of morphological differences between sister lineages is slowed by stabilizing selection preventing phenotypic differentiation. In North America, Bicknell's Thrush (Catharus bicknelli) and its sister species, the Gray-cheeked Thrush (Catharus minimus), are parapatrically breeding migratory songbirds, distinguishable in nature only by subtle differences in song and coloration, and were recognized as distinct species only in the 1990s. Previous molecular studies have estimated that the species diverged approximately 120,000-420,000 YBP and found very low levels of introgression despite their similarity and sympatry in the spring (prebreeding) migration. To further clarify the history, genetic divergence, genomic structure, and adaptive processes in C. bicknelli and C. minimus, we sequenced and assembled high-coverage reference genomes of both species and resequenced genomes from population samples of C. bicknelli, C. minimus, and two individuals of the Swainson's Thrush (Catharus ustulatus). The genome of C. bicknelli exhibits markedly higher abundances of transposable elements compared with other Catharus and chicken. Demographic and admixture analyses confirm moderate genome-wide differentiation (Fst ≈ 0.10) and limited gene flow between C. bicknelli and C. minimus, but suggest a more recent divergence than estimates based on mtDNA. We find evidence of rapid evolution of the Z-chromosome and elevated divergence consistent with natural selection on genomic regions near genes involved with neuronal processes in C. bicknelli. These genomes are a useful resource for future investigations of speciation, migration, and adaptation in Catharus thrushes.
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Affiliation(s)
- Flavia Termignoni-Garcia
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | | | - Johnathan Clark
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
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10
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Wong ELY, Hiscock SJ, Filatov DA. The Role of Interspecific Hybridisation in Adaptation and Speciation: Insights From Studies in Senecio. FRONTIERS IN PLANT SCIENCE 2022; 13:907363. [PMID: 35812981 PMCID: PMC9260247 DOI: 10.3389/fpls.2022.907363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 06/03/2022] [Indexed: 05/08/2023]
Abstract
Hybridisation is well documented in many species, especially plants. Although hybrid populations might be short-lived and do not evolve into new lineages, hybridisaiton could lead to evolutionary novelty, promoting adaptation and speciation. The genus Senecio (Asteraceae) has been actively used to unravel the role of hybridisation in adaptation and speciation. In this article, we first briefly describe the process of hybridisation and the state of hybridisation research over the years. We then discuss various roles of hybridisation in plant adaptation and speciation illustrated with examples from different Senecio species, but also mention other groups of organisms whenever necessary. In particular, we focus on the genomic and transcriptomic consequences of hybridisation, as well as the ecological and physiological aspects from the hybrids' point of view. Overall, this article aims to showcase the roles of hybridisation in speciation and adaptation, and the research potential of Senecio, which is part of the ecologically and economically important family, Asteraceae.
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Affiliation(s)
- Edgar L. Y. Wong
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
- *Correspondence: Edgar L. Y. Wong,
| | - Simon J. Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
- Oxford Botanic Garden and Arboretum, Oxford, United Kingdom
| | - Dmitry A. Filatov
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
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Zhang Z, Zheng Y, Zhang J, Wang N, Wang Y, Liu W, Bai S, Xie W. High-Altitude Genetic Selection and Genome-Wide Association Analysis of Yield-Related Traits in Elymus sibiricus L. Using SLAF Sequencing. FRONTIERS IN PLANT SCIENCE 2022; 13:874409. [PMID: 35800604 PMCID: PMC9253694 DOI: 10.3389/fpls.2022.874409] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 05/26/2022] [Indexed: 05/04/2023]
Abstract
The genetic adaptations to harsh climatic conditions in high altitudes and genetic basis of important agronomic traits are poorly understood in Elymus sibiricus L. In this study, an association population of 210 genotypes was used for population structure, selective sweep analysis, and genome-wide association study (GWAS) based on 88,506 single nucleotide polymorphisms (SNPs). We found 965 alleles under the natural selection of high altitude, which included 7 hub genes involved in the response to UV, and flavonoid and anthocyanin biosynthetic process based on the protein-protein interaction (PPI) analysis. Using a mixed linear model (MLM), the GWAS test identified a total of 1,825 significant loci associated with 12 agronomic traits. Based on the gene expression data of two wheat cultivars and the PPI analysis, we finally identified 12 hub genes. Especially, in plant height traits, the top hub gene (TOPLESS protein) encoding auxins and jasmonic acid signaling pathway, shoot apical meristem specification, and xylem and phloem pattern formation was highly overexpressed. These genes might play essential roles in controlling the growth and development of E. sibiricus. Therefore, this study provides fundamental insights relevant to hub genes and will benefit molecular breeding and improvement in E. sibiricus and other Elymus species.
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Affiliation(s)
- Zongyu Zhang
- The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Yuying Zheng
- The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Junchao Zhang
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, China
| | - Na Wang
- The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Yanrong Wang
- The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Wenhui Liu
- Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau, Qinghai Academy of Animal Science and Veterinary Medicine, Xining, China
| | - Shiqie Bai
- Sichuan Academy of Grassland Science, Chengdu, China
| | - Wengang Xie
- The State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- *Correspondence: Wengang Xie,
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12
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Zheng W, Yan LJ, Burgess KS, Luo YH, Zou JY, Qin HT, Wang JH, Gao LM. Natural hybridization among three Rhododendron species (Ericaceae) revealed by morphological and genomic evidence. BMC PLANT BIOLOGY 2021; 21:529. [PMID: 34763662 PMCID: PMC8582147 DOI: 10.1186/s12870-021-03312-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 11/02/2021] [Indexed: 06/08/2023]
Abstract
BACKGROUND Natural hybridization can influence the adaptive response to selection and accelerate species diversification. Understanding the composition and structure of hybrid zones may elucidate patterns of hybridization processes that are important to the formation and maintenance of species, especially for taxa that have experienced rapidly adaptive radiation. Here, we used morphological traits, ddRAD-seq and plastid DNA sequence data to investigate the structure of a Rhododendron hybrid zone and uncover the hybridization patterns among three sympatric and closely related species. RESULTS Our results show that the hybrid zone is complex, where bi-directional hybridization takes place among the three sympatric parental species: R. spinuliferum, R. scabrifolium, and R. spiciferum. Hybrids between R. spinuliferum and R. spiciferum (R. ×duclouxii) comprise multiple hybrid classes and a high proportion of F1 generation hybrids, while a novel hybrid taxon between R. spinuliferum and R. scabrifolium dominated the F2 generation, but no backcross individuals were detected. The hybrid zone showed basically coincident patterns of population structure between genomic and morphological data. CONCLUSIONS Natural hybridization exists among the three Rhododendron species in the hybrid zone, although patterns of hybrid formation vary between hybrid taxa, which may result in different evolutionary outcomes. This study represents a unique opportunity to dissect the ecological and evolutionary mechanisms associated with adaptive radiation of Rhododendron species in a biodiversity hotspot.
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Affiliation(s)
- Wei Zheng
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China
- University of Chinese Academy of Sciences, 10049, Beijing, China
| | - Li-Jun Yan
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China
- University of Chinese Academy of Sciences, 10049, Beijing, China
- College of Vocational and Technical Education, Yunnan Normal University, 650092, Kunming, Yunnan, China
| | - Kevin S Burgess
- Department of Biology, Columbus State University, University System of Georgia, 31907-5645, Columbus, GA, USA
| | - Ya-Huang Luo
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China
| | - Jia-Yun Zou
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China
- University of Chinese Academy of Sciences, 10049, Beijing, China
| | - Han-Tao Qin
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China
- University of Chinese Academy of Sciences, 10049, Beijing, China
| | - Ji-Hua Wang
- The Flower Research Institute, Yunnan Academy of Agricultural Sciences, 650205, Kunming, China.
| | - Lian-Ming Gao
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, 650201, Kunming, Yunnan, China.
- Lijiang Forest Biodiversity National Observation and Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, 674100, Lijiang, Yunnan, China.
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13
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Dolby GA. Towards a unified framework to study causality in Earth-life systems. Mol Ecol 2021; 30:5628-5642. [PMID: 34427004 PMCID: PMC9292314 DOI: 10.1111/mec.16142] [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: 03/07/2021] [Revised: 07/17/2021] [Accepted: 08/20/2021] [Indexed: 01/04/2023]
Abstract
There is considerable interest in better understanding how earth processes shape the generation and distribution of life on Earth. This question, at its heart, is one of causation. In this article I propose that at a regional level, earth processes can be thought of as behaving somewhat deterministically and may have an organized effect on the diversification and distribution of species. However, the study of how landscape features shape biology is challenged by pseudocongruent or collinear variables. I demonstrate that causal structures can be used to depict the cause–effect relationships between earth processes and biological patterns using recent examples from the literature about speciation and species richness in montane settings. This application shows that causal diagrams can be used to better decipher the details of causal relationships by motivating new hypotheses. Additionally, the abstraction of this knowledge into structural equation metamodels can be used to formulate theory about relationships within Earth–life systems more broadly. Causal structures are a natural point of collaboration between biologists and Earth scientists, and their use can mitigate against the risk of misassigning causality within studies. My goal is that by applying causal theory through application of causal structures, we can build a systems‐level understanding of what landscape features or earth processes most shape the distribution and diversification of species, what types of organisms are most affected, and why.
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Affiliation(s)
- Greer A Dolby
- School of Life Sciences, Arizona State University, Tempe, Arizona, USA.,Center for Mechanisms of Evolution, Arizona State University, Tempe, Arizona, USA
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14
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Wang X, Liu S, Zuo H, Zheng W, Zhang S, Huang Y, Pingcuo G, Ying H, Zhao F, Li Y, Liu J, Yi TS, Zan Y, Larkin RM, Deng X, Zeng X, Xu Q. Genomic basis of high-altitude adaptation in Tibetan Prunus fruit trees. Curr Biol 2021; 31:3848-3860.e8. [PMID: 34314676 DOI: 10.1016/j.cub.2021.06.062] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/25/2021] [Accepted: 06/22/2021] [Indexed: 01/03/2023]
Abstract
The Great Himalayan Mountains and their foothills are believed to be the place of origin and development of many plant species. The genetic basis of adaptation to high plateaus is a fascinating topic that is poorly understood at the population level. We comprehensively collected and sequenced 377 accessions of Prunus germplasm along altitude gradients ranging from 2,067 to 4,492 m in the Himalayas. We de novo assembled three high-quality genomes of Tibetan Prunus species. A comparative analysis of Prunus genomes indicated a remarkable expansion of the SINE retrotransposons occurred in the genomes of Tibetan species. We observed genetic differentiation between Tibetan peaches from high and low altitudes and that genes associated with light stress signaling, especially UV stress signaling, were enriched in the differentiated regions. By profiling the metabolomes of Tibetan peach fruit, we determined 379 metabolites had significant genetic correlations with altitudes and that in particular phenylpropanoids were positively correlated with altitudes. We identified 62 Tibetan peach-specific SINEs that colocalized with metabolites differentially accumualted in Tibetan relative to cultivated peach. We demonstrated that two SINEs were inserted in a locus controlling the accumulation of 3-O-feruloyl quinic acid. SINE1 was specific to Tibetan peach. SINE2 was predominant in high altitudes and associated with the accumulation of 3-O-feruloyl quinic acid. These genomic and metabolic data for Prunus populations native to the Himalayan region indicate that the expansion of SINE retrotransposons helped Tibetan Prunus species adapt to the harsh environment of the Himalayan plateau by promoting the accumulation of beneficial metabolites.
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Affiliation(s)
- Xia Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Shengjun Liu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Hao Zuo
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Weikang Zheng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Shanshan Zhang
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China
| | - Yue Huang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Gesang Pingcuo
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China
| | - Hong Ying
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China
| | - Fan Zhao
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China
| | - Yuanrong Li
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China
| | - Junwei Liu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Ting-Shuang Yi
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Yanjun Zan
- Department of Forestry Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå 90736, Sweden
| | - Robert M Larkin
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China
| | - Xiuli Zeng
- Qinghai-Tibet Plateau Fruit Trees Scientific Observation Test Station (Ministry of Agriculture and Rural Affairs), Lhasa, Tibet 850032, China; Institute of Vegetables, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet 850002, China.
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Key Laboratory of Horticultural Crop (Fruit trees) Biology and Genetic Improvement (Ministry of Agriculture and Rural Affairs), Huazhong Agricultural University, Wuhan 430070, China.
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15
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García-Rodríguez A, Martínez PA, Oliveira BF, Velasco JA, Pyron RA, Costa GC. Amphibian Speciation Rates Support a General Role of Mountains as Biodiversity Pumps. Am Nat 2021; 198:E68-E79. [PMID: 34403310 DOI: 10.1086/715500] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractContinental mountain areas cover <15% of global land surface, yet these regions concentrate >80% of global terrestrial diversity. One prominent hypothesis to explain this pattern proposes that high mountain diversities could be explained by higher diversification rates in regions of high topographic complexity (HTC). While high speciation in mountains has been detected for particular clades and regions, the global extent to which lineages experience faster speciation in mountains remains unknown. Here we addressed this issue using amphibians as a model system (>7,000 species), and we found that families showing high speciation rates contain a high proportion of species distributed in mountains. Moreover, we found that lineages inhabiting areas of HTC speciate faster than lineages occupying areas that are topographically less complex. When comparing across regions, we identified the same pattern in five biogeographical realms where higher speciation rates are associated with higher levels of complex topography. Low-magnitude differences in speciation rates between some low and high complex topographies suggest that high mountain diversity is also affected by low extinction and/or high colonization rates. Nevertheless, our results bolster the importance of mountains as engines of speciation at different geographical scales and highlight their importance for the conservation of global biodiversity.
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16
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Demari-Silva B, Laporta GZ, de Oliveira TMP, Sallum MAM. Evidence of Elevational Speciation in Kerteszia cruzii (Diptera: Culicidae) in the Ribeira Valley, São Paulo, Brazil. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.707642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Kerteszia cruzii [former Anopheles (Kerteszia) cruzii] is a bromeliad mosquito widespread in the Brazilian Atlantic rainforest. In South-eastern Brazil, it plays an important role in malaria transmission because it was infected with at least four Plasmodium species. There is robust evidence that Ke. cruzii is a species complex. We used single nucleotide polymorphisms (SNPs) from a nextRAD sequence (nextera-tagmented, reductively amplified DNA) to investigate the genetic structure of Ke. cruzii in the Ribeira Valley, South-eastern Brazil. Furthermore, we verified whether the genetic structure was associated with forest cover, elevation, slope, and vegetation physiognomy. Our results showed two distinct lineages in the studied region associated with elevation and isolation by distance. The first lineage included samples from coastal localities and the second comprised specimens from inland or mountain sites. At one sampling locality (Esteiro do Morro in Cananéia municipality), both lineages are sympatric. These results are in accordance with previously published data that showed elevated stratification in Ke. cruzii. However, Fst values did not indicate the existence of cryptic or sister species in Ke. cruzii in this region, we concluded that elevational speciation probably occurs, and we hypothesized that differences in population structure found might be associated with the distribution of bromeliad species.
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17
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Lim MCW, Bi K, Witt CC, Graham CH, Dávalos LM. Pervasive Genomic Signatures of Local Adaptation to Altitude Across Highland Specialist Andean Hummingbird Populations. J Hered 2021; 112:229-240. [PMID: 33631009 DOI: 10.1093/jhered/esab008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 02/23/2021] [Indexed: 01/28/2023] Open
Abstract
Populations along steep environmental gradients are subject to differentiating selection that can result in local adaptation, despite countervailing gene flow, and genetic drift. In montane systems, where species are often restricted to narrow ranges of elevation, it is unclear whether the selection is strong enough to influence functional differentiation of subpopulations differing by a few hundred meters in elevation. We used targeted capture of 12 501 exons from across the genome, including 271 genes previously implicated in altitude adaptation, to test for adaptation to local elevations for 2 highland hummingbird species, Coeligena violifer (n = 62) and Colibri coruscans (n = 101). For each species, we described population genetic structure across the complex geography of the Peruvian Andes and, while accounting for this structure, we tested whether elevational allele frequency clines in single nucleotide polymorphisms (SNPs) showed evidence for local adaptation to elevation. Although the 2 species exhibited contrasting population genetic structures, we found signatures of clinal genetic variation with shifts in elevation in both. The genes with SNP-elevation associations included candidate genes previously discovered for high-elevation adaptation as well as others not previously identified, with cellular functions related to hypoxia response, energy metabolism, and immune function, among others. Despite the homogenizing effects of gene flow and genetic drift, natural selection on parts of the genome evidently optimizes elevation-specific cellular function even within elevation range-restricted montane populations. Consequently, our results suggest local adaptation occurring in narrow elevation bands in tropical mountains, such as the Andes, may effectively make them "taller" biogeographic barriers.
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Affiliation(s)
- Marisa C W Lim
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY
| | - Ke Bi
- Museum of Vertebrate Zoology, University of California, Berkeley, CA.,California Institute for Quantitative Biosciences, University of California Berkeley, Berkeley, CA (Bi)
| | - Christopher C Witt
- Museum of Southwestern Biology and Department of Biology, University of New Mexico, Albuquerque, NM
| | - Catherine H Graham
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY.,Swiss Federal Research Institute (WSL), Birmensdorf, Switzerland
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY.,Consortium for Inter-Disciplinary Environmental Research, Stony Brook University, Stony Brook, NY
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18
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Leal BSS, Brandão MM, Palma-Silva C, Pinheiro F. Differential gene expression reveals mechanisms related to habitat divergence between hybridizing orchids from the Neotropical coastal plains. BMC PLANT BIOLOGY 2020; 20:554. [PMID: 33302865 PMCID: PMC7731501 DOI: 10.1186/s12870-020-02757-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/25/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Closely related hybridizing species are ideal systems for identifying genomic regions underlying adaptive divergence. Although gene expression plays a central role in determining ecologically-based phenotypic differences, few studies have inferred the role of gene expression for adaptive divergence in Neotropical systems. In this study, we conduct genome-wide expression analysis alongside soil elemental analysis in sympatric and allopatric populations of Epidendrum fulgens and E. puniceoluteum (Orchidaceae), which occur in contrasting adjacent habitats in the Neotropical coastal plains. RESULTS These species were highly differentiated by their gene expression profiles, as determined by 18-21% of transcripts. Gene ontology (GO) terms associated with reproductive processes were enriched according to comparisons between species in both allopatric and sympatric populations. Species showed differential expression in genes linked to salt and waterlogging tolerance according to comparisons between species in sympatry, and biological processes related to environmental stimulus appeared as representative among those transcripts associated with edaphic characteristics in each sympatric zone. Hybrids, in their turn, were well differentiated from E. fulgens, but exhibited a similar gene expression profile to flooding-tolerant E. puniceolutem. When compared with parental species, hybrids showed no transcripts with additive pattern of expression and increased expression for almost all transgressive transcripts. CONCLUSIONS This study sheds light on general mechanisms promoting ecological differentiation and assortative mating, and suggests candidate genes, such as those encoding catalase and calcium-dependent protein kinase, underling adaptation to harsh edaphic conditions in the Neotropical coastal plains. Moreover, it demonstrates that differential gene expression plays a central role in determining ecologically-based phenotypic differences among co-occurring species and their hybrids.
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Affiliation(s)
| | - Marcelo Mendes Brandão
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil
| | - Clarisse Palma-Silva
- Departamento de Biologia Vegetal, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil
| | - Fabio Pinheiro
- Departamento de Biologia Vegetal, Universidade Estadual de Campinas, Campinas, SP, 13083-862, Brazil
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19
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Coppi A, Baker AJM, Bettarini I, Colzi I, Echevarria G, Pazzagli L, Gonnelli C, Selvi F. Population Genetics of Odontarrhena (Brassicaceae) from Albania: The Effects of Anthropic Habitat Disturbance, Soil, and Altitude on a Ni-Hyperaccumulator Plant Group from a Major Serpentine Hotspot. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1686. [PMID: 33271845 PMCID: PMC7759883 DOI: 10.3390/plants9121686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 11/22/2022]
Abstract
Albanian taxa and populations of the genus Odontarrhena are most promising candidates for research on metal tolerance and Ni-agromining, but their genetic structure remains unknown. We investigated phylogenetic relationships and genetic differentiation in relation to distribution and ploidy of the taxa, anthropic site disturbance, elevation, soil type, and trace metals at each population site. After performing DNA sequencing of selected accessions, we applied DNA-fingerprinting to analyze the genetic structure of 32 populations from ultramafic and non-ultramafic outcrops across Albania. Low sequence divergence resulted in poorly resolved phylograms, but supported affinity between the two diploid serpentine endemics O. moravensis and O. rigida. Analysis of molecular variance (AMOVA) revealed significant population differentiation, but no isolation by distance. Among-population variation was higher in polyploids than in diploids, in which genetic distances were lower. Genetic admixing at population and individual level occurred especially in the polyploids O. chalcidica, O. decipiens, and O. smolikana. Admixing increased with site disturbance. Outlier loci were higher in serpentine populations but decreased along altitude with lower drought and heat stress. Genetic variability gained by gene flow and hybridization at contact zones with "resident" species of primary ultramafic habitats promoted expansion of the tetraploid O. chalcidica across anthropogenic sites.
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Affiliation(s)
- Andrea Coppi
- Department of Biology, University of Firenze, 50121 Firenze, Italy;
| | - Alan J. M. Baker
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane QLD 4072, Australia; (A.J.M.B.); (G.E.)
- Laboratoire Sols et Environnement, Université de Lorraine/INRA, F-54000 Vandoeuvre-lès-Nancy, France
| | - Isabella Bettarini
- Department of Biomedical Experimental and Clinical Sciences, University of Firenze, 50121 Firenze, Italy; (I.B.); (L.P.)
| | - Ilaria Colzi
- Department of Biology, University of Firenze, 50121 Firenze, Italy;
| | - Guillaume Echevarria
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane QLD 4072, Australia; (A.J.M.B.); (G.E.)
- Laboratoire Sols et Environnement, Université de Lorraine/INRA, F-54000 Vandoeuvre-lès-Nancy, France
| | - Luigia Pazzagli
- Department of Biomedical Experimental and Clinical Sciences, University of Firenze, 50121 Firenze, Italy; (I.B.); (L.P.)
| | | | - Federico Selvi
- Department of Agriculture, Food, Environment and Forestry, Laboratories of Botany, 50121 Firenze, Italy;
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20
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Understanding the genetic diversity of the guayabillo (Psidium galapageium), an endemic plant of the Galapagos Islands. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01350] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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21
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Linck E, Freeman BG, Dumbacher JP. Speciation and gene flow across an elevational gradient in New Guinea kingfishers. J Evol Biol 2020; 33:1643-1652. [PMID: 32916016 DOI: 10.1111/jeb.13698] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/24/2020] [Accepted: 08/29/2020] [Indexed: 01/01/2023]
Abstract
Closely related species with parapatric elevational ranges are ubiquitous in tropical mountains worldwide. The gradient speciation hypothesis proposes that these series are the result of in situ ecological speciation driven by divergent selection across elevation. Direct tests of this scenario have been hampered by the difficulty inferring the geographic arrangement of populations at the time of divergence. In cichlids, sticklebacks and Timema stick insects, support for ecological speciation driven by other selective pressures has come from demonstrating parallel speciation, where divergence proceeds independently across replicated environmental gradients. Here, we take advantage of the unique geography of the island of New Guinea to test for parallel gradient speciation in replicated populations of Syma kingfishers that show extremely subtle differentiation across elevation and between historically isolated mountain ranges. We find that currently described high-elevation and low-elevation species have reciprocally monophyletic gene trees and form nuclear DNA clusters, rejecting this hypothesis. However, demographic modelling suggests selection has likely maintained species boundaries in the face of gene flow following secondary contact. We compile evidence from the published literature to show that although in situ gradient speciation in labile organisms such as birds appears rare, divergent selection and post-speciation gene flow may be an underappreciated force in the origin of elevational series and tropical beta diversity along mountain slopes.
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Affiliation(s)
- Ethan Linck
- Department of Biology & Burke Museum of Natural History & Culture, University of Washington, Seattle, WA, USA
| | - Benjamin G Freeman
- Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - John P Dumbacher
- Ornithology & Mammalogy, California Academy of Sciences, San Francisco, CA, USA
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22
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Nevado B, Harris SA, Beaumont MA, Hiscock SJ. Rapid homoploid hybrid speciation in British gardens: The origin of Oxford ragwort (
Senecio squalidus
). Mol Ecol 2020; 29:4221-4233. [DOI: 10.1111/mec.15630] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 08/21/2020] [Accepted: 08/26/2020] [Indexed: 01/17/2023]
Affiliation(s)
- Bruno Nevado
- Department of Plant Sciences University of Oxford Oxford UK
| | | | | | - Simon J. Hiscock
- Department of Plant Sciences University of Oxford Oxford UK
- Oxford Botanic Garden and Arboretum Oxford UK
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23
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Van Buskirk J, Jansen van Rensburg A. Relative importance of isolation‐by‐environment and other determinants of gene flow in an alpine amphibian. Evolution 2020; 74:962-978. [DOI: 10.1111/evo.13955] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/26/2020] [Accepted: 03/09/2020] [Indexed: 02/07/2023]
Affiliation(s)
- Josh Van Buskirk
- Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Zurich 8057 Switzerland
| | - Alexandra Jansen van Rensburg
- Department of Evolutionary Biology and Environmental StudiesUniversity of Zurich Zurich 8057 Switzerland
- School of Biological SciencesUniversity of Bristol Bristol BS8 1TQ United Kingdom
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24
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Walter GM, Abbott RJ, Brennan AC, Bridle JR, Chapman M, Clark J, Filatov D, Nevado B, Ortiz-Barrientos D, Hiscock SJ. Senecio as a model system for integrating studies of genotype, phenotype and fitness. THE NEW PHYTOLOGIST 2020; 226:326-344. [PMID: 31951018 DOI: 10.1111/nph.16434] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 12/17/2019] [Indexed: 05/24/2023]
Abstract
Two major developments have made it possible to use examples of ecological radiations as model systems to understand evolution and ecology. First, the integration of quantitative genetics with ecological experiments allows detailed connections to be made between genotype, phenotype, and fitness in the field. Second, dramatic advances in molecular genetics have created new possibilities for integrating field and laboratory experiments with detailed genetic sequencing. Combining these approaches allows evolutionary biologists to better study the interplay between genotype, phenotype, and fitness to explore a wide range of evolutionary processes. Here, we present the genus Senecio (Asteraceae) as an excellent system to integrate these developments, and to address fundamental questions in ecology and evolution. Senecio is one of the largest and most phenotypically diverse genera of flowering plants, containing species ranging from woody perennials to herbaceous annuals. These Senecio species exhibit many growth habits, life histories, and morphologies, and they occupy a multitude of environments. Common within the genus are species that have hybridized naturally, undergone polyploidization, and colonized diverse environments, often through rapid phenotypic divergence and adaptive radiation. These diverse experimental attributes make Senecio an attractive model system in which to address a broad range of questions in evolution and ecology.
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Affiliation(s)
- Greg M Walter
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Richard J Abbott
- School of Biology, University of St Andrews, St Andrews, Fife, KY16 9TH, UK
| | - Adrian C Brennan
- School of Biological and Biomedical Sciences, University of Durham, Durham, DH1 3LE, UK
| | - Jon R Bridle
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Mark Chapman
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - James Clark
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Dmitry Filatov
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | - Bruno Nevado
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
| | | | - Simon J Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, OX1 3RB, UK
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25
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Page A, Gibson J, Meyer RS, Chapman MA. Eggplant Domestication: Pervasive Gene Flow, Feralization, and Transcriptomic Divergence. Mol Biol Evol 2020; 36:1359-1372. [PMID: 31039581 DOI: 10.1093/molbev/msz062] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In the context of food security, examining the genomics of domestication will help identify genes underlying adaptive and economically important phenotypes, for example, larger fruit, improved taste, and loss of agronomically inferior phenotypes. Examination of genome-scale single nucleotide polymorphisms demonstrates the relationships between wild ancestors of eggplant (Solanum melongena L.), confirming that Solanum insanum L. is the wild progenitor. This species is split roughly into an Eastern (Malaysian, Thai, and Vietnamese) and Western (Indian, Madagascan, and Sri Lankan) group, with domesticates derived from the former. Additional "wild" accessions from India appear to be feral escapes, derived multiple times from domesticated varieties through admixture. Accessions with small egg-shaped fruit are generally found intermixed with East Asian Solanum insanum confirming they are primitive relative to the large-fruited domesticates. Comparative transcriptomics was used to track the loci under selection. Sequence analysis revealed a genetic bottleneck reducing variation by almost 50% in the primitive accessions relative to the wild species and a further 10% in the landraces. We also show evidence for selection on genes with a role in response to wounding and apoptosis. Genes showing a significant difference in expression between wild and primitive or between primitive and landrace genepools were mostly (>75%) downregulated in the derived populations and enriched for gene ontologies related to defense, flowering, signaling, and response to biotic and abiotic stimuli. This work reveals genomic changes involved in crop domestication and improvement, and the population genetics work explains why defining the eggplant domestication trajectory has been so challenging.
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Affiliation(s)
- Anna Page
- Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Jane Gibson
- Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Rachel S Meyer
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA
| | - Mark A Chapman
- Biological Sciences, University of Southampton, Southampton, United Kingdom
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26
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Origin of Elevational Replacements in a Clade of Nearly Flightless Birds: Most Diversity in Tropical Mountains Accumulates via Secondary Contact Following Allopatric Speciation. NEOTROPICAL DIVERSIFICATION: PATTERNS AND PROCESSES 2020. [DOI: 10.1007/978-3-030-31167-4_23] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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27
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Wong ELY, Nevado B, Osborne OG, Papadopulos AST, Bridle JR, Hiscock SJ, Filatov DA. Strong divergent selection at multiple loci in two closely related species of ragworts adapted to high and low elevations on Mount Etna. Mol Ecol 2019; 29:394-412. [PMID: 31793091 DOI: 10.1111/mec.15319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 11/28/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022]
Abstract
Recently diverged species present particularly informative systems for studying speciation and maintenance of genetic divergence in the face of gene flow. We investigated speciation in two closely related Senecio species, S. aethnensis and S. chrysanthemifolius, which grow at high and low elevations, respectively, on Mount Etna, Sicily and form a hybrid zone at intermediate elevations. We used a newly generated genome-wide single nucleotide polymorphism (SNP) dataset from 192 individuals collected over 18 localities along an elevational gradient to reconstruct the likely history of speciation, identify highly differentiated SNPs, and estimate the strength of divergent selection. We found that speciation in this system involved heterogeneous and bidirectional gene flow along the genome, and species experienced marked population size changes in the past. Furthermore, we identified highly-differentiated SNPs between the species, some of which are located in genes potentially involved in ecological differences between species (such as photosynthesis and UV response). We analysed the shape of these SNPs' allele frequency clines along the elevational gradient. These clines show significantly variable coincidence and concordance, indicative of the presence of multifarious selective forces. Selection against hybrids is estimated to be very strong (0.16-0.78) and one of the highest reported in literature. The combination of strong cumulative selection across the genome and previously identified intrinsic incompatibilities probably work together to maintain the genetic and phenotypic differentiation between these species - pointing to the importance of considering both intrinsic and extrinsic factors when studying divergence and speciation.
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Affiliation(s)
- Edgar L Y Wong
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Bruno Nevado
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Owen G Osborne
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | | | - Jon R Bridle
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Simon J Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, UK
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28
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Chen LY, VanBuren R, Paris M, Zhou H, Zhang X, Wai CM, Yan H, Chen S, Alonge M, Ramakrishnan S, Liao Z, Liu J, Lin J, Yue J, Fatima M, Lin Z, Zhang J, Huang L, Wang H, Hwa TY, Kao SM, Choi JY, Sharma A, Song J, Wang L, Yim WC, Cushman JC, Paull RE, Matsumoto T, Qin Y, Wu Q, Wang J, Yu Q, Wu J, Zhang S, Boches P, Tung CW, Wang ML, Coppens d'Eeckenbrugge G, Sanewski GM, Purugganan MD, Schatz MC, Bennetzen JL, Lexer C, Ming R. The bracteatus pineapple genome and domestication of clonally propagated crops. Nat Genet 2019; 51:1549-1558. [PMID: 31570895 DOI: 10.1038/s41588-019-0506-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/28/2019] [Indexed: 11/09/2022]
Abstract
Domestication of clonally propagated crops such as pineapple from South America was hypothesized to be a 'one-step operation'. We sequenced the genome of Ananas comosus var. bracteatus CB5 and assembled 513 Mb into 25 chromosomes with 29,412 genes. Comparison of the genomes of CB5, F153 and MD2 elucidated the genomic basis of fiber production, color formation, sugar accumulation and fruit maturation. We also resequenced 89 Ananas genomes. Cultivars 'Smooth Cayenne' and 'Queen' exhibited ancient and recent admixture, while 'Singapore Spanish' supported a one-step operation of domestication. We identified 25 selective sweeps, including a strong sweep containing a pair of tandemly duplicated bromelain inhibitors. Four candidate genes for self-incompatibility were linked in F153, but were not functional in self-compatible CB5. Our findings support the coexistence of sexual recombination and a one-step operation in the domestication of clonally propagated crops. This work guides the exploration of sexual and asexual domestication trajectories in other clonally propagated crops.
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Affiliation(s)
- Li-Yu Chen
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Robert VanBuren
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Horticulture, Michigan State University, East Lansing, MI, USA
| | - Margot Paris
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Hongye Zhou
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Xingtan Zhang
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ching Man Wai
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hansong Yan
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shuai Chen
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Michael Alonge
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA
| | | | - Zhenyang Liao
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Juan Liu
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jishan Lin
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jingjing Yue
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mahpara Fatima
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhicong Lin
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jisen Zhang
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lixian Huang
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hao Wang
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Teh-Yang Hwa
- Department of Agronomy, National Taiwan University, Taipei, ROC
| | - Shu-Min Kao
- Department of Agronomy, National Taiwan University, Taipei, ROC
| | - Jae Young Choi
- Department of Biology, Center for Genomics and Systems Biology, New York University, NY, New York, USA
| | - Anupma Sharma
- Texas A&M AgriLife Research, Texas A&M University System, Dallas, TX, USA
| | - Jian Song
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Lulu Wang
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Won C Yim
- Department of Biochemistry and Molecular Biology, MS330, University of Nevada, Reno, NV, USA
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, MS330, University of Nevada, Reno, NV, USA
| | - Robert E Paull
- Department of Tropical Plant and Soil Sciences, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Tracie Matsumoto
- USDA-ARS, Pacific Basin Agricultural Research Center, Hilo, HI, USA
| | - Yuan Qin
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qingsong Wu
- South Subtropical Crops Research Institute, CATAS, Zhanjiang, China
| | - Jianping Wang
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Qingyi Yu
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China.,Texas A&M AgriLife Research, Texas A&M University System, Dallas, TX, USA
| | - Jun Wu
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Shaoling Zhang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Peter Boches
- USDA-ARS, Pacific Basin Agricultural Research Center, Hilo, HI, USA
| | - Chih-Wei Tung
- Department of Agronomy, National Taiwan University, Taipei, ROC
| | - Ming-Li Wang
- Hawaii Agriculture Research Center, Kunia, HI, USA
| | - Geo Coppens d'Eeckenbrugge
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement, UMR AGAP, Montpellier, France.,AGAP, Université de Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Garth M Sanewski
- Queensland Department of Agriculture and Fisheries, Nambour, Queensland, Australia
| | - Michael D Purugganan
- Department of Biology, Center for Genomics and Systems Biology, New York University, NY, New York, USA
| | - Michael C Schatz
- Department of Computer Science, Johns Hopkins University, Baltimore, MD, USA
| | | | - Christian Lexer
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria.
| | - Ray Ming
- FAFU and UIUC-SIB Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China. .,Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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29
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Brennan AC, Hiscock SJ, Abbott RJ. Completing the hybridization triangle: the inheritance of genetic incompatibilities during homoploid hybrid speciation in ragworts ( Senecio). AOB PLANTS 2019; 11:ply078. [PMID: 30740200 PMCID: PMC6360072 DOI: 10.1093/aobpla/ply078] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 01/04/2019] [Indexed: 05/24/2023]
Abstract
A new homoploid hybrid lineage needs to establish a degree of reproductive isolation from its parent species if it is to persist as an independent entity, but the role hybridization plays in this process is known in only a handful of cases. The homoploid hybrid ragwort species, Senecio squalidus (Oxford ragwort), originated following the introduction of hybrid plants to the UK approximately 320 years ago. The source of the hybrid plants was from a naturally occurring hybrid zone between S. aethnensis and S. chrysanthemifolius on Mount Etna, Sicily. Previous studies of the parent species found evidence for multiple incompatibility loci causing transmission ratio distortion of genetic markers in their hybrid progeny. This study closes the hybridization triangle by reporting a genetic mapping analysis of the remaining two paired cross combinations between S. squalidus and its parents. Genetic maps produced from F2 mapping families were generally collinear but with half of the linkage groups showing evidence of genomic reorganization between genetic maps. The new maps produced from crosses between S. squalidus and each parent showed multiple incompatibility loci distributed across the genome, some of which co-locate with previously reported incompatibility loci between the parents. These findings suggest that this young homoploid hybrid species has inherited a unique combination of genomic rearrangements and incompatibilities from its parents that contribute to its reproductive isolation.
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Affiliation(s)
- Adrian C Brennan
- Department of Biosciences, University of Durham, South Road, Durham, UK
- School of Biology, University of St Andrews, St Andrews, Fife, UK
| | - Simon J Hiscock
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | - Richard J Abbott
- School of Biology, University of St Andrews, St Andrews, Fife, UK
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30
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Ru D, Sun Y, Wang D, Chen Y, Wang T, Hu Q, Abbott RJ, Liu J. Population genomic analysis reveals that homoploid hybrid speciation can be a lengthy process. Mol Ecol 2018; 27:4875-4887. [PMID: 30357974 DOI: 10.1111/mec.14909] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 08/22/2018] [Accepted: 10/02/2018] [Indexed: 12/26/2022]
Abstract
An increasing number of species are thought to have originated by homoploid hybrid speciation (HHS), but in only a handful of cases are details of the process known. A previous study indicated that Picea purpurea, a conifer in the Qinghai-Tibet Plateau (QTP), originated through HHS from P. likiangensis and P. wilsonii. To investigate this origin in more detail, we analysed transcriptome data for 114 individuals collected from 34 populations of the three Picea species from their core distributions in the QTP. Phylogenetic, principal component and admixture analyses of nuclear SNPs showed the species to be delimited genetically and that P. purpurea was admixed with approximately 60% of its ancestry derived from P. wilsonii and 40% from P. likiangensis. Coalescent simulations revealed the best-fitting model of origin involved formation of an intermediate hybrid lineage between P. likiangensis and P. wilsonii approximately 6 million years ago (mya), which backcrossed to P. wilsonii to form P. purpurea approximately one mya. The intermediate hybrid lineage no longer exists and is referred to as a "ghost" lineage. Our study emphasizes the power of population genomic analysis combined with coalescent analysis for reconstructing the stages involved in the origin of a homoploid hybrid species over an extended period. In contrast to other studies, we show that these stages can in some instances span a relatively long period of evolutionary time.
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Affiliation(s)
- Dafu Ru
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Yongshuai Sun
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China.,CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, PR China
| | - Donglei Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Yang Chen
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Tianjing Wang
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Quanjun Hu
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | | | - Jianquan Liu
- Key Laboratory for Bio-resource and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
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31
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Brown AP, Arias-Rodriguez L, Yee MC, Tobler M, Kelley JL. Concordant Changes in Gene Expression and Nucleotides Underlie Independent Adaptation to Hydrogen-Sulfide-Rich Environments. Genome Biol Evol 2018; 10:2867-2881. [PMID: 30215710 PMCID: PMC6225894 DOI: 10.1093/gbe/evy198] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2018] [Indexed: 12/23/2022] Open
Abstract
The colonization of novel environments often involves changes in gene expression, protein coding sequence, or both. Studies of how populations adapt to novel conditions, however, often focus on only one of these two processes, potentially missing out on the relative importance of different parts of the evolutionary process. In this study, our objectives were 1) to better understand the qualitative concordance between conclusions drawn from analyses of differential expression and changes in genic sequence and 2) to quantitatively test whether differentially expressed genes were enriched for sites putatively under positive selection within gene regions. To achieve this, we compared populations of fish (Poecilia mexicana) that have independently adapted to hydrogen-sulfide-rich environments in southern Mexico to adjacent populations residing in nonsulfidic waters. Specifically, we used RNA-sequencing data to compare both gene expression and DNA sequence differences between populations. Analyzing these two different data types led to similar conclusions about which biochemical pathways (sulfide detoxification and cellular respiration) were involved in adaptation to sulfidic environments. Additionally, we found a greater overlap between genes putatively under selection and differentially expressed genes than expected by chance. We conclude that considering both differential expression and changes in DNA sequence led to a more comprehensive understanding of how these populations adapted to extreme environmental conditions. Our results imply that changes in both gene expression and DNA sequence-sometimes at the same loci-may be involved in adaptation.
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Affiliation(s)
- Anthony P Brown
- School of Biological Sciences, Washington State University, 100 Dairy Road, Pullman, WA 99164
| | - Lenin Arias-Rodriguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma de Tabasco (UJAT), C.P. 86150, Villahermosa, Tabasco, México
| | - Muh-Ching Yee
- Stanford Functional Genomics Facility, CCSR 0120, Stanford, CA 94305
| | - Michael Tobler
- Division of Biology, Kansas State University, 116 Ackert Hall, Manhattan, KS 66506
| | - Joanna L Kelley
- School of Biological Sciences, Washington State University, 100 Dairy Road, Pullman, WA 99164
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32
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Fraïsse C, Roux C, Gagnaire PA, Romiguier J, Faivre N, Welch JJ, Bierne N. The divergence history of European blue mussel species reconstructed from Approximate Bayesian Computation: the effects of sequencing techniques and sampling strategies. PeerJ 2018; 6:e5198. [PMID: 30083438 PMCID: PMC6071616 DOI: 10.7717/peerj.5198] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 06/19/2018] [Indexed: 01/25/2023] Open
Abstract
Genome-scale diversity data are increasingly available in a variety of biological systems, and can be used to reconstruct the past evolutionary history of species divergence. However, extracting the full demographic information from these data is not trivial, and requires inferential methods that account for the diversity of coalescent histories throughout the genome. Here, we evaluate the potential and limitations of one such approach. We reexamine a well-known system of mussel sister species, using the joint site frequency spectrum (jSFS) of synonymous mutations computed either from exome capture or RNA-seq, in an Approximate Bayesian Computation (ABC) framework. We first assess the best sampling strategy (number of: individuals, loci, and bins in the jSFS), and show that model selection is robust to variation in the number of individuals and loci. In contrast, different binning choices when summarizing the jSFS, strongly affect the results: including classes of low and high frequency shared polymorphisms can more effectively reveal recent migration events. We then take advantage of the flexibility of ABC to compare more realistic models of speciation, including variation in migration rates through time (i.e., periodic connectivity) and across genes (i.e., genome-wide heterogeneity in migration rates). We show that these models were consistently selected as the most probable, suggesting that mussels have experienced a complex history of gene flow during divergence and that the species boundary is semi-permeable. Our work provides a comprehensive evaluation of ABC demographic inference in mussels based on the coding jSFS, and supplies guidelines for employing different sequencing techniques and sampling strategies. We emphasize, perhaps surprisingly, that inferences are less limited by the volume of data, than by the way in which they are analyzed.
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Affiliation(s)
- Christelle Fraïsse
- Institut des Sciences de l’Evolution UMR5554, University Montpellier, CNRS, IRD, EPHE, Montpellier, France
- Department of Genetics, University of Cambridge, Cambridge, UK
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Camille Roux
- Université de Lille, Unité Evo-Eco-Paléo (EEP), UMR 8198, Villeneuve d’Ascq, France
| | - Pierre-Alexandre Gagnaire
- Institut des Sciences de l’Evolution UMR5554, University Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Jonathan Romiguier
- Institut des Sciences de l’Evolution UMR5554, University Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Nicolas Faivre
- Institut des Sciences de l’Evolution UMR5554, University Montpellier, CNRS, IRD, EPHE, Montpellier, France
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - John J. Welch
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Nicolas Bierne
- Institut des Sciences de l’Evolution UMR5554, University Montpellier, CNRS, IRD, EPHE, Montpellier, France
- Department of Genetics, University of Cambridge, Cambridge, UK
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33
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Nevado B, Contreras-Ortiz N, Hughes C, Filatov DA. Pleistocene glacial cycles drive isolation, gene flow and speciation in the high-elevation Andes. THE NEW PHYTOLOGIST 2018; 219:779-793. [PMID: 29862512 DOI: 10.1111/nph.15243] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/30/2018] [Indexed: 05/10/2023]
Abstract
Mountain ranges are amongst the most species-rich habitats, with many large and rapid evolutionary radiations. The tempo and mode of diversification in these systems are key unanswered questions in evolutionary biology. Here we study the Andean Lupinus radiation to understand the processes driving very rapid diversification in montane systems. We use genomic and transcriptomic data of multiple species and populations, and apply phylogenomic and demographic analyses to test whether diversification proceeded without interspecific gene flow - as expected if Andean orogeny and geographic isolation were the main drivers of diversification - or if diversification was accompanied by gene flow, in which case other processes were probably involved. We uncover several episodes of gene flow between species, including very recent events likely to have been prompted by changes in habitat connectivity during Pleistocene glacial cycles. Furthermore, we find that gene flow between species was heterogeneously distributed across the genome. We argue that exceptionally fast diversification of Andean Lupinus was partly a result of Late Pleistocene glacial cycles, with associated cycles of expansion and contraction driving geographic isolation or secondary contact of species. Furthermore, heterogeneous gene flow across the genome suggests a role for selection and ecological speciation in rapid diversification in this system.
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Affiliation(s)
- Bruno Nevado
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Natalia Contreras-Ortiz
- Laboratorio de Botánica y Sistemática, Departamento de Ciencias Biológicas, Universidad de los Andes, Apartado Aéreo, 4976, Bogotá, Colombia
- Jardín Botánico de Bogotá 'José Celestino Mutis', Avenida Calle 63 No. 68-95, Bogotá DC, Colombia
| | - Colin Hughes
- Department of Systematic & Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland
| | - Dmitry A Filatov
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
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34
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Graham AM, Lavretsky P, Muñoz-Fuentes V, Green AJ, Wilson RE, McCracken KG. Migration-Selection Balance Drives Genetic Differentiation in Genes Associated with High-Altitude Function in the Speckled Teal (Anas flavirostris) in the Andes. Genome Biol Evol 2018; 10:14-32. [PMID: 29211852 PMCID: PMC5757641 DOI: 10.1093/gbe/evx253] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/30/2017] [Indexed: 12/30/2022] Open
Abstract
Local adaptation frequently occurs across populations as a result of migration-selection balance between divergent selective pressures and gene flow associated with life in heterogeneous landscapes. Studying the effects of selection and gene flow on the adaptation process can be achieved in systems that have recently colonized extreme environments. This study utilizes an endemic South American duck species, the speckled teal (Anas flavirostris), which has both high- and low-altitude populations. High-altitude speckled teal (A. f. oxyptera) are locally adapted to the Andean environment and mostly allopatric from low-altitude birds (A. f. flavirostris); however, there is occasional gene flow across altitudinal gradients. In this study, we used next-generation sequencing to explore genetic patterns associated with high-altitude adaptation in speckled teal populations, as well as the extent to which the balance between selection and migration have affected genetic architecture. We identified a set of loci with allele frequencies strongly correlated with altitude, including those involved in the insulin-like signaling pathway, bone morphogenesis, oxidative phosphorylation, responders to hypoxia-induced DNA damage, and feedback loops to the hypoxia-inducible factor pathway. These same outlier loci were found to have depressed gene flow estimates, as well as being highly concentrated on the Z-chromosome. Our results suggest a multifactorial response to life at high altitudes through an array of interconnected pathways that are likely under positive selection and whose genetic components seem to be providing an effective genomic barrier to interbreeding, potentially functioning as an avenue for population divergence and speciation.
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Affiliation(s)
| | | | - Violeta Muñoz-Fuentes
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Estación Biológica de Doñana, EBD-CSIC, Sevilla, Spain
| | - Andy J Green
- Estación Biológica de Doñana, EBD-CSIC, Sevilla, Spain
| | - Robert E Wilson
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska, Fairbanks
| | - Kevin G McCracken
- Department of Biology, University of Miami
- Institute of Arctic Biology and University of Alaska Museum, University of Alaska, Fairbanks
- Rosenstiel School of Marine and Atmospheric Sciences, University of Miami
- John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine
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35
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Harris SE, Munshi-South J. Signatures of positive selection and local adaptation to urbanization in white-footed mice (Peromyscus leucopus). Mol Ecol 2017; 26:6336-6350. [PMID: 28980357 DOI: 10.1111/mec.14369] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 09/25/2017] [Indexed: 02/06/2023]
Abstract
Urbanization significantly alters natural ecosystems and has accelerated globally. Urban wildlife populations are often highly fragmented by human infrastructure, and isolated populations may adapt in response to local urban pressures. However, relatively few studies have identified genomic signatures of adaptation in urban animals. We used a landscape genomic approach to examine signatures of selection in urban populations of white-footed mice (Peromyscus leucopus) in New York City. We analysed 154,770 SNPs identified from transcriptome data from 48 P. leucopus individuals from three urban and three rural populations and used outlier tests to identify evidence of urban adaptation. We accounted for demography by simulating a neutral SNP data set under an inferred demographic history as a null model for outlier analysis. We also tested whether candidate genes were associated with environmental variables related to urbanization. In total, we detected 381 outlier loci and after stringent filtering, identified and annotated 19 candidate loci. Many of the candidate genes were involved in metabolic processes and have well-established roles in metabolizing lipids and carbohydrates. Our results indicate that white-footed mice in New York City are adapting at the biomolecular level to local selective pressures in urban habitats. Annotation of outlier loci suggests selection is acting on metabolic pathways in urban populations, likely related to novel diets in cities that differ from diets in less disturbed areas.
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Affiliation(s)
- Stephen E Harris
- The Graduate Center, City University of New York (CUNY), New York, NY, USA
| | - Jason Munshi-South
- Louis Calder Center-Biological Field Station, Fordham University, Armonk, NY, USA
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36
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Loire E, Tusso S, Caminade P, Severac D, Boursot P, Ganem G, Smadja CM. Do changes in gene expression contribute to sexual isolation and reinforcement in the house mouse? Mol Ecol 2017. [PMID: 28626946 DOI: 10.1111/mec.14212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Expression divergence, rather than sequence divergence, has been shown to be important in speciation, particularly in the early stages of divergence of traits involved in reproductive isolation. In the two European subspecies of house mice, Mus musculus musculus and Mus musculus domesticus, earlier studies have demonstrated olfactory-based assortative mate preference in populations close to their hybrid zone. It has been suggested that this behaviour evolved following the recent secondary contact between the two taxa (~3,000 years ago) in response to selection against hybridization. To test for a role of changes in gene expression in the observed behavioural shift, we conducted a RNA sequencing experiment on mouse vomeronasal organs. Key candidate genes for pheromone-based subspecies recognition, the vomeronasal receptors, are expressed in these organs. Overall patterns of gene expression varied significantly between samples from the two subspecies, with a large number of differentially expressed genes between the two taxa. In contrast, only ~200 genes were found repeatedly differentially expressed between populations within M. m. musculus that did or did not display assortative mate preferences (close to or more distant from the hybrid zone, respectively), with an overrepresentation of genes belonging to vomeronasal receptor family 2. These receptors are known to play a key role in recognition of chemical cues that handle information about genetic identity. Interestingly, four of five of these differentially expressed receptors belong to the same phylogenetic cluster, suggesting specialization of a group of closely related receptors in the recognition of odorant signals that may allow subspecies recognition and assortative mating.
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Affiliation(s)
- Etienne Loire
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
| | - Sergio Tusso
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
| | - Pierre Caminade
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
| | - Dany Severac
- Montpellier GenomiX (MGX), Institut de Génomique Fonctionnelle, Montpellier Cedex 5, France
| | - Pierre Boursot
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
| | - Guila Ganem
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
| | - Carole M Smadja
- Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de l'Evolution UMR 5554, Institut pour la Recherche et le Développement (IRD), EPHE, Université de Montpellier, Montpellier, France
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37
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Angeletti D, Cimmaruta R, Sebbio C, Bellisario B, Carere C, Nascetti G. Environmental heterogeneity promotes microgeographic genetic divergence in the Mediterranean killifish Aphanius fasciatus(Cyprinodontidae). ETHOL ECOL EVOL 2017. [DOI: 10.1080/03949370.2016.1188159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Dario Angeletti
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
| | - Roberta Cimmaruta
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
| | - Claudia Sebbio
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
- Department of Monitoring of Environmental Quality, Italian National Institute for Environmental Protection and Research (ISPRA), Via di Castel Romano 100, 00128 Rome, Italy
| | - Bruno Bellisario
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
| | - Claudio Carere
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, Sorbonne Paris Cité, Paris, France
| | - Giuseppe Nascetti
- Department of Ecological and Biological Sciences, Ichthyogenic Experimental Marine Center (CISMAR), Tuscia University, Borgo Le Saline, 01016 Tarquinia (Viterbo), Italy
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38
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Bog M, Bässler C, Oberprieler C. Lost in the hybridisation vortex: high-elevation Senecio hercynicus (Compositae, Senecioneae) is genetically swamped by its congener S. ovatus in the Bavarian Forest National Park (SE Germany). Evol Ecol 2017. [DOI: 10.1007/s10682-017-9890-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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39
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Jones KE, Pérez-Espona S, Reyes-Betancort JA, Pattinson D, Caujapé-Castells J, Hiscock SJ, Carine MA. Why do different oceanic archipelagos harbour contrasting levels of species diversity? The macaronesian endemic genus Pericallis (Asteraceae) provides insight into explaining the 'Azores diversity Enigma'. BMC Evol Biol 2016; 16:202. [PMID: 27717307 PMCID: PMC5055660 DOI: 10.1186/s12862-016-0766-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/27/2016] [Indexed: 11/30/2022] Open
Abstract
Background Oceanic archipelagos typically harbour extensive radiations of flowering plants and a high proportion of endemics, many of which are restricted to a single island (Single Island Endemics; SIEs). The Azores represents an anomaly as overall levels of endemism are low; there are few SIEs and few documented cases of intra-archipelago radiations. The distinctiveness of the flora was first recognized by Darwin and has been referred to as the ‘Azores Diversity Enigma’ (ADE). Diversity patterns in the Macaronesian endemic genus Pericallis (Asteraceae) exemplify the ADE. In this study we used morphometric, Amplified Length Polymorphisms, and bioclimatic data for herbaceous Pericallis lineages endemic to the Azores and the Canaries, to test two key hypotheses proposed to explain the ADE: i) that it is a taxonomic artefact or Linnean shortfall, ie. the under description of taxa in the Azores or the over-splitting of taxa in the Canaries and (ii) that it reflects the greater ecological homogeneity of the Azores, which results in limited opportunity for ecological diversification compared to the Canaries. Results In both the Azores and the Canaries, morphological patterns were generally consistent with current taxonomic classifications. However, the AFLP data showed no genetic differentiation between the two currently recognized Azorean subspecies that are ecologically differentiated. Instead, genetic diversity in the Azores was structured geographically across the archipelago. In contrast, in the Canaries genetic differentiation was mostly consistent with morphology and current taxonomic treatments. Both Azorean and Canarian lineages exhibited ecological differentiation between currently recognized taxa. Conclusions Neither a Linnean shortfall nor the perceived ecological homogeneity of the Azores fully explained the ADE-like pattern observed in Pericallis. Whilst variation in genetic data and morphological data in the Canaries were largely congruent, this was not the case in the Azores, where genetic patterns reflected inter-island geographical isolation, and morphology reflected intra-island bioclimatic variation. The combined effects of differences in (i) the extent of geographical isolation, (ii) population sizes and (iii) geographical occupancy of bioclimatic niche space, coupled with the morphological plasticity of Pericallis, may all have contributed to generating the contrasting patterns observed in the archipelagos. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0766-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- K E Jones
- Botanischer Garten und Botanisches Museum Berlin-Dahlem, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Königin-Luise Str. 6-8, Berlin, 14195, Germany.
| | - S Pérez-Espona
- Estación Biológica de Doñana, CSIC, C./ Américo Vespucio s/n, Sevilla, E-41092, Spain
| | - J A Reyes-Betancort
- Jardín de Aclimatación de La Oratava (ICIA), C/Retama 2, Puerto de la Cruz, Tenerife, 38400, Spain
| | - D Pattinson
- Natural History Museum, Cromwell Road, London, SE7 5ED, UK.,Present address: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK
| | - J Caujapé-Castells
- Jardín Botánico Canario "Viera y Clavijo"-Unidad Asociada al CSIC (Cabildo de Gran Canaria), Camino del palmeral 15 (Tafira Alta), Las Palmas de Gran Canaria, 35017, Spain
| | - S J Hiscock
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - M A Carine
- Natural History Museum, Cromwell Road, London, SE7 5ED, UK
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40
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Vallejo-Marín M, Hiscock SJ. Hybridization and hybrid speciation under global change. THE NEW PHYTOLOGIST 2016; 211:1170-87. [PMID: 27214560 DOI: 10.1111/nph.14004] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/07/2016] [Indexed: 05/24/2023]
Abstract
Contents 1170 I. 1170 II. 1172 III. 1175 IV. 1180 V. 1183 1184 References 1184 SUMMARY: An unintended consequence of global change is an increase in opportunities for hybridization among previously isolated lineages. Here we illustrate how global change can facilitate the breakdown of reproductive barriers and the formation of hybrids, drawing on the flora of the British Isles for insight. Although global change may ameliorate some of the barriers preventing hybrid establishment, for example by providing new ecological niches for hybrids, it will have limited effects on environment-independent post-zygotic barriers. For example, genic incompatibilities and differences in chromosome numbers and structure within hybrid genomes are unlikely to be affected by global change. We thus speculate that global change will have a larger effect on eroding pre-zygotic barriers (eco-geographical isolation and phenology) than post-zygotic barriers, shifting the relative importance of these two classes of reproductive barriers from what is usually seen in naturally produced hybrids where pre-zygotic barriers are the largest contributors to reproductive isolation. Although the long-term fate of neo-hybrids is still to be determined, the massive impact of global change on the dynamics and distribution of biodiversity generates an unprecedented opportunity to study large numbers of unpredicted, and often replicated, hybridization 'experiments', allowing us to peer into the birth and death of evolutionary lineages.
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Affiliation(s)
- Mario Vallejo-Marín
- Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK
| | - Simon J Hiscock
- University of Oxford Botanic Garden, Rose Lane, Oxford, OX1 4AZ, UK
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41
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Christe C, Stölting KN, Paris M, Fraїsse C, Bierne N, Lexer C. Adaptive evolution and segregating load contribute to the genomic landscape of divergence in two tree species connected by episodic gene flow. Mol Ecol 2016; 26:59-76. [PMID: 27447453 DOI: 10.1111/mec.13765] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/09/2016] [Accepted: 07/14/2016] [Indexed: 12/18/2022]
Abstract
Speciation often involves repeated episodes of genetic contact between divergent populations before reproductive isolation (RI) is complete. Whole-genome sequencing (WGS) holds great promise for unravelling the genomic bases of speciation. We have studied two ecologically divergent, hybridizing species of the 'model tree' genus Populus (poplars, aspens, cottonwoods), Populus alba and P. tremula, using >8.6 million single nucleotide polymorphisms (SNPs) from WGS of population pools. We used the genomic data to (i) scan these species' genomes for regions of elevated and reduced divergence, (ii) assess key aspects of their joint demographic history based on genomewide site frequency spectra (SFS) and (iii) infer the potential roles of adaptive and deleterious coding mutations in shaping the genomic landscape of divergence. We identified numerous small, unevenly distributed genome regions without fixed polymorphisms despite high overall genomic differentiation. The joint SFS was best explained by ancient and repeated gene flow and allowed pinpointing candidate interspecific migrant tracts. The direction of selection (DoS) differed between genes in putative migrant tracts and the remainder of the genome, thus indicating the potential roles of adaptive divergence and segregating deleterious mutations on the evolution and breakdown of RI. Genes affected by positive selection during divergence were enriched for several functionally interesting groups, including well-known candidate 'speciation genes' involved in plant innate immunity. Our results suggest that adaptive divergence affects RI in these hybridizing species mainly through intrinsic and demographic processes. Integrating genomic with molecular data holds great promise for revealing the effects of particular genetic pathways on speciation.
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Affiliation(s)
- Camille Christe
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland
| | - Kai N Stölting
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland
| | - Margot Paris
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland
| | - Christelle Fraїsse
- Institut des Sciences de l'Evolution (UMR 5554), CNRS-UM2-IRD, Place Eugene Bataillon, F-34095, Montpellier, France.,Station Méditerranéenne de l'Environnement Littoral, Université Montpellier 2, 2 Rue des Chantiers, F-34200, Séte, France
| | - Nicolas Bierne
- Institut des Sciences de l'Evolution (UMR 5554), CNRS-UM2-IRD, Place Eugene Bataillon, F-34095, Montpellier, France.,Station Méditerranéenne de l'Environnement Littoral, Université Montpellier 2, 2 Rue des Chantiers, F-34200, Séte, France
| | - Christian Lexer
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700, Fribourg, Switzerland.,Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030, Vienna, Austria
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42
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White OW, Doo B, Carine MA, Chapman MA. Transcriptome sequencing and simple sequence repeat marker development for three Macaronesian endemic plant species. APPLICATIONS IN PLANT SCIENCES 2016; 4:apps1600050. [PMID: 27610280 PMCID: PMC5001862 DOI: 10.3732/apps.1600050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Oceanic islands offer unparalleled opportunities to investigate evolutionary processes such as adaptation and speciation. However, few genomic resources are available for oceanic island endemics. In this study, we publish transcriptome sequences from three Macaronesian endemic plant species (Argyranthemum broussonetii [Asteraceae], Descurainia bourgaeana [Brassicaceae], and Echium wildpretii [Boraginaceae]) that are representative of lineages that have radiated in the region. In addition, the utility of transcriptome data for marker development is demonstrated. METHODS AND RESULTS Transcriptomes from the three plant species were sequenced, assembled, and annotated. Between 1972 and 2282 simple sequence repeats (SSRs) were identified for each taxon. Primers were designed and tested for 30 of the candidate SSRs identified in Argyranthemum, of which 12 amplified well across three species and eight were polymorphic. CONCLUSIONS We demonstrate here that a single transcriptome sequence is sufficient to identify hundreds of polymorphic SSR markers. The SSRs are applicable to a wide range of questions relating to the evolution of island lineages.
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Affiliation(s)
- Oliver W. White
- Plants Division, Natural History Museum, London SW7 5BD, United Kingdom
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Bethany Doo
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Mark A. Carine
- Plants Division, Natural History Museum, London SW7 5BD, United Kingdom
| | - Mark A. Chapman
- Centre for Biological Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
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Dunning LT, Hipperson H, Baker WJ, Butlin RK, Devaux C, Hutton I, Igea J, Papadopulos AST, Quan X, Smadja CM, Turnbull CGN, Savolainen V. Ecological speciation in sympatric palms: 1. Gene expression, selection and pleiotropy. J Evol Biol 2016; 29:1472-87. [PMID: 27177130 PMCID: PMC6680112 DOI: 10.1111/jeb.12895] [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: 11/05/2015] [Revised: 05/04/2016] [Accepted: 05/11/2016] [Indexed: 02/02/2023]
Abstract
Ecological speciation requires divergent selection, reproductive isolation and a genetic mechanism to link the two. We examined the role of gene expression and coding sequence evolution in this process using two species of Howea palms that have diverged sympatrically on Lord Howe Island, Australia. These palms are associated with distinct soil types and have displaced flowering times, representing an ideal candidate for ecological speciation. We generated large amounts of RNA‐Seq data from multiple individuals and tissue types collected on the island from each of the two species. We found that differentially expressed loci as well as those with divergent coding sequences between Howea species were associated with known ecological and phenotypic differences, including response to salinity, drought, pH and flowering time. From these loci, we identified potential ‘ecological speciation genes’ and further validate their effect on flowering time by knocking out orthologous loci in a model plant species. Finally, we put forward six plausible ecological speciation loci, providing support for the hypothesis that pleiotropy could help to overcome the antagonism between selection and recombination during speciation with gene flow.
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Affiliation(s)
- L T Dunning
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - H Hipperson
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - W J Baker
- Royal Botanic Gardens, Kew, Richmond, UK
| | - R K Butlin
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,Sven Lovén Centre for Marine Sciences, Tjärnö, University of Gothenburg, Stromstäd, Sweden
| | - C Devaux
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - I Hutton
- Lord Howe Island Museum, Lord Howe Island, NSW, Australia
| | - J Igea
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - A S T Papadopulos
- Department of Life Sciences, Imperial College London, Ascot, UK.,Royal Botanic Gardens, Kew, Richmond, UK
| | - X Quan
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - C M Smadja
- Department of Life Sciences, Imperial College London, Ascot, UK
| | - C G N Turnbull
- Department of Life Sciences, Imperial College London, London, UK
| | - V Savolainen
- Department of Life Sciences, Imperial College London, Ascot, UK.,Royal Botanic Gardens, Kew, Richmond, UK
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44
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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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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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Osborne OG, Chapman MA, Nevado B, Filatov DA. Maintenance of Species Boundaries Despite Ongoing Gene Flow in Ragworts. Genome Biol Evol 2016; 8:1038-47. [PMID: 26979797 PMCID: PMC4860686 DOI: 10.1093/gbe/evw053] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2016] [Indexed: 12/22/2022] Open
Abstract
The role of hybridization between diversifying species has been the focus of a huge amount of recent evolutionary research. While gene flow can prevent speciation or initiate species collapse, it can also generate new hybrid species. Similarly, while adaptive divergence can be wiped out by gene flow, new adaptive variation can be introduced via introgression. The relative frequency of these outcomes, and indeed the frequency of hybridization and introgression in general are largely unknown. One group of closely-related species with several documented cases of hybridization is the Mediterranean ragwort (genus: Senecio) species-complex. Examples of both polyploid and homoploid hybrid speciation are known in the clade, although their evolutionary relationships and the general frequency of introgressive hybridization among them remain unknown. Using a whole genome gene-space dataset comprising eight Senecio species we fully resolve the phylogeny of these species for the first time despite phylogenetic incongruence across the genome. Using a D-statistic approach, we demonstrate previously unknown cases of introgressive hybridization between multiple pairs of taxa across the species tree. This is an important step in establishing these species as a study system for diversification with gene flow, and suggests that introgressive hybridization may be a widespread and important process in plant evolution.
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Affiliation(s)
- Owen G Osborne
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom Department of Life Sciences, Imperial College London - Silwood Park Campus, Berkshire, United Kingdom
| | - Mark A Chapman
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom Department of Life Sciences, Imperial College London - Silwood Park Campus, Berkshire, United Kingdom Centre for Biological Sciences, Faculty of Natural & Environmental Sciences, University of Southampton, Southampton, United Kingdom
| | - Bruno Nevado
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - Dmitry A Filatov
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
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Zhao SY, Chen LY, Muchuku JK, Hu GW, Wang QF. Genetic Adaptation of Giant Lobelias (Lobelia aberdarica and Lobelia telekii) to Different Altitudes in East African Mountains. FRONTIERS IN PLANT SCIENCE 2016; 7:488. [PMID: 27148313 PMCID: PMC4828460 DOI: 10.3389/fpls.2016.00488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/25/2016] [Indexed: 06/01/2023]
Abstract
The giant lobelias in East African mountains are good models for studying molecular mechanisms of adaptation to different altitudes. In this study, we generated RNA-seq data of a middle-altitude species Lobelia aberdarica and a high-altitude species L. telekii, followed by selective pressure estimation of their orthologous genes. Our aim was to explore the important genes potentially involved in adaptation to different altitudes. About 9.3 Gb of clean nucleotides, 167,929-170,534 unigenes with total lengths of 159,762,099-171,138,936 bp for each of the two species were generated. OrthoMCL method identified 3,049 1:1 orthologous genes (each species was represented by one ortholog). Estimations of non-synonymous to synonymous rate were performed using an approximate method and a maximum likelihood method in PAML. Eighty-five orthologous genes were under positive selection. At least 8 of these genes are possibly involved in DNA repair, response to DNA damage and temperature stimulus, and regulation of gene expression, which hints on how giant lobelias adapt to high altitudinal environment that characterized by cold, low oxygen, and strong ultraviolet radiation. The negatively selected genes are over-represented in Gene Ontology terms of hydrolase, macromolecular complex assembly among others. This study sheds light on understanding the molecular mechanism of adaptation to different altitudes, and provides genomic resources for further studies of giant lobelias.
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Affiliation(s)
- Shu-Ying Zhao
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- Sino-Africa Joint Research Centre, Chinese Academy of SciencesWuhan, China
| | - Ling-Yun Chen
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- Sino-Africa Joint Research Centre, Chinese Academy of SciencesWuhan, China
| | - John K. Muchuku
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- Sino-Africa Joint Research Centre, Chinese Academy of SciencesWuhan, China
| | - Guang-Wan Hu
- Sino-Africa Joint Research Centre, Chinese Academy of SciencesWuhan, China
| | - Qing-Feng Wang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of SciencesWuhan, China
- Sino-Africa Joint Research Centre, Chinese Academy of SciencesWuhan, China
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Parkinson JE, Baumgarten S, Michell CT, Baums IB, LaJeunesse TC, Voolstra CR. Gene Expression Variation Resolves Species and Individual Strains among Coral-Associated Dinoflagellates within the Genus Symbiodinium. Genome Biol Evol 2016; 8:665-80. [PMID: 26868597 PMCID: PMC4824173 DOI: 10.1093/gbe/evw019] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Reef-building corals depend on symbiotic mutualisms with photosynthetic dinoflagellates in the genus Symbiodinium. This large microalgal group comprises many highly divergent lineages (“Clades A–I”) and hundreds of undescribed species. Given their ecological importance, efforts have turned to genomic approaches to characterize the functional ecology of Symbiodinium. To date, investigators have only compared gene expression between representatives from separate clades—the equivalent of contrasting genera or families in other dinoflagellate groups—making it impossible to distinguish between clade-level and species-level functional differences. Here, we examined the transcriptomes of four species within one Symbiodinium clade (Clade B) at ∼20,000 orthologous genes, as well as multiple isoclonal cell lines within species (i.e., cultured strains). These species span two major adaptive radiations within Clade B, each encompassing both host-specialized and ecologically cryptic taxa. Species-specific expression differences were consistently enriched for photosynthesis-related genes, likely reflecting selection pressures driving niche diversification. Transcriptional variation among strains involved fatty acid metabolism and biosynthesis pathways. Such differences among individuals are potentially a major source of physiological variation, contributing to the functional diversity of coral holobionts composed of unique host–symbiont genotype pairings. Our findings expand the genomic resources available for this important symbiont group and emphasize the power of comparative transcriptomics as a method for studying speciation processes and interindividual variation in nonmodel organisms.
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Affiliation(s)
| | - Sebastian Baumgarten
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Craig T Michell
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | | | | | - Christian R Voolstra
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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49
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Hu XS, Filatov DA. The large-X effect in plants: increased species divergence and reduced gene flow on the Silene X-chromosome. Mol Ecol 2016; 25:2609-19. [PMID: 26479725 DOI: 10.1111/mec.13427] [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: 07/07/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/25/2022]
Abstract
The disproportionately large involvement of the X-chromosome in the isolation of closely related species (the large-X effect) has been reported for many animals, where X-linked genes are mostly hemizygous in the heterogametic sex. The expression of deleterious recessive mutations is thought to drive the frequent involvement of the X-chromosome in hybrid sterility, as well as to reduce interspecific gene flow for X-linked genes. Here, we evaluate the role of the X-chromosome in the speciation of two closely related plant species - the white and red campions (Silene latifolia and S. dioica) - that hybridize widely across Europe. The two species evolved separate sexes and sex chromosomes relatively recently (~10(7) years), and unlike most animal species, most X-linked genes have intact Y-linked homologs. We demonstrate that the X-linked genes show a very small and insignificant amount of interspecific gene flow, while gene flow involving autosomal loci is significant and sufficient to homogenize the gene pools of the two species. These findings are consistent with the hypothesis of the large-X effect in Silene and comprise the first report of this effect in plants. Nonhemizygosity of many X-linked genes in Silene males indicates that exposure of recessive mutations to selection may not be essential for the occurrence of the large-X effect. Several possible causes of the large-X effect in Silene are discussed.
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Affiliation(s)
- Xin-Sheng Hu
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX13RB, UK
| | - Dmitry A Filatov
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX13RB, UK
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50
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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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