1
|
Glover AN, Sousa VC, Ridenbaugh RD, Sim SB, Geib SM, Linnen CR. Recurrent selection shapes the genomic landscape of differentiation between a pair of host-specialized haplodiploids that diverged with gene flow. Mol Ecol 2024:e17509. [PMID: 39165007 DOI: 10.1111/mec.17509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 07/16/2024] [Accepted: 08/02/2024] [Indexed: 08/22/2024]
Abstract
Understanding the genetics of adaptation and speciation is critical for a complete picture of how biodiversity is generated and maintained. Heterogeneous genomic differentiation between diverging taxa is commonly documented, with genomic regions of high differentiation interpreted as resulting from differential gene flow, linked selection and reduced recombination rates. Disentangling the roles of each of these non-exclusive processes in shaping genome-wide patterns of divergence is challenging but will enhance our knowledge of the repeatability of genomic landscapes across taxa. Here, we combine whole-genome resequencing and genome feature data to investigate the processes shaping the genomic landscape of differentiation for a sister-species pair of haplodiploid pine sawflies, Neodiprion lecontei and Neodiprion pinetum. We find genome-wide correlations between genome features and summary statistics are consistent with pervasive linked selection, with patterns of diversity and divergence more consistently predicted by exon density and recombination rate than the neutral mutation rate (approximated by dS). We also find that both global and local patterns of FST, dXY and π provide strong support for recurrent selection as the primary selective process shaping variation across pine sawfly genomes, with some contribution from balancing selection and lineage-specific linked selection. Because inheritance patterns for haplodiploid genomes are analogous to those of sex chromosomes, we hypothesize that haplodiploids may be especially prone to recurrent selection, even if gene flow occurred throughout divergence. Overall, our study helps fill an important taxonomic gap in the genomic landscape literature and contributes to our understanding of the processes that shape genome-wide patterns of genetic variation.
Collapse
Affiliation(s)
- Ashleigh N Glover
- Department of Biology, University of Kentucky, Lexington, Kentucky, USA
| | - Vitor C Sousa
- Department of Animal Biology, CE3C - Center for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, University of Lisbon, Lisbon, Lisboa, Portugal
| | - Ryan D Ridenbaugh
- Department of Biology, University of Kentucky, Lexington, Kentucky, USA
| | - Sheina B Sim
- USDA-ARS Daniel K. Inouye US Pacific Basin Agricultural Research Center Tropical Pest Genetics and Molecular Biology Research Unit, Hilo, Hawaii, USA
| | - Scott M Geib
- USDA-ARS Daniel K. Inouye US Pacific Basin Agricultural Research Center Tropical Pest Genetics and Molecular Biology Research Unit, Hilo, Hawaii, USA
| | | |
Collapse
|
2
|
Martin CA, Sheppard EC, Ali HAA, Illera JC, Suh A, Spurgin LG, Richardson DS. Genomic landscapes of divergence among island bird populations: Evidence of parallel adaptation but at different loci? Mol Ecol 2024; 33:e17365. [PMID: 38733214 DOI: 10.1111/mec.17365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 03/01/2024] [Indexed: 05/13/2024]
Abstract
When populations colonise new environments, they may be exposed to novel selection pressures but also suffer from extensive genetic drift due to founder effects, small population sizes and limited interpopulation gene flow. Genomic approaches enable us to study how these factors drive divergence, and disentangle neutral effects from differentiation at specific loci due to selection. Here, we investigate patterns of genetic diversity and divergence using whole-genome resequencing (>22× coverage) in Berthelot's pipit (Anthus berthelotii), a passerine endemic to the islands of three north Atlantic archipelagos. Strong environmental gradients, including in pathogen pressure, across populations in the species range, make it an excellent system in which to explore traits important in adaptation and/or incipient speciation. First, we quantify how genomic divergence accumulates across the speciation continuum, that is, among Berthelot's pipit populations, between sub species across archipelagos, and between Berthelot's pipit and its mainland ancestor, the tawny pipit (Anthus campestris). Across these colonisation timeframes (2.1 million-ca. 8000 years ago), we identify highly differentiated loci within genomic islands of divergence and conclude that the observed distributions align with expectations for non-neutral divergence. Characteristic signatures of selection are identified in loci associated with craniofacial/bone and eye development, metabolism and immune response between population comparisons. Interestingly, we find limited evidence for repeated divergence of the same loci across the colonisation range but do identify different loci putatively associated with the same biological traits in different populations, likely due to parallel adaptation. Incipient speciation across these island populations, in which founder effects and selective pressures are strong, may therefore be repeatedly associated with morphology, metabolism and immune defence.
Collapse
Affiliation(s)
- Claudia A Martin
- School of Biological Sciences, University of East Anglia, Norfolk, UK
- Terrestrial Ecology Unit, Biology Department, Ghent University, Ghent, Belgium
- School of Biological Sciences, The University of Edinburgh, Edinburgh, UK
| | | | - Hisham A A Ali
- Department of Biology, Edward Grey Institute of Field Ornithology, University of Oxford, Oxford, UK
| | - Juan Carlos Illera
- Biodiversity Research Institute (CSIC-Oviedo University-Principality of Asturias), University of Oviedo, Mieres, Asturias, Spain
| | - Alexander Suh
- School of Biological Sciences, University of East Anglia, Norfolk, UK
- Department of Organismal Biology - Systematic Biology, Evolutionary Biology Centre (EBC), Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norfolk, UK
| | | |
Collapse
|
3
|
Maier PA, Vandergast AG, Bohonak AJ. Yosemite toad (Anaxyrus canorus) transcriptome reveals interplay between speciation genes and adaptive introgression. Mol Ecol 2024; 33:e17317. [PMID: 38488670 DOI: 10.1111/mec.17317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 02/15/2024] [Accepted: 02/23/2024] [Indexed: 04/09/2024]
Abstract
Genomes are heterogeneous during the early stages of speciation, with small 'islands' of DNA appearing to reflect strong adaptive differences, surrounded by vast seas of relative homogeneity. As species diverge, secondary contact zones between them can act as an interface and selectively filter through advantageous alleles of hybrid origin. Such introgression is another important adaptive process, one that allows beneficial mosaics of recombinant DNA ('rivers') to flow from one species into another. Although genomic islands of divergence appear to be associated with reproductive isolation, and genomic rivers form by adaptive introgression, it is unknown whether islands and rivers tend to be the same or different loci. We examined three replicate secondary contact zones for the Yosemite toad (Anaxyrus canorus) using two genomic data sets and a morphometric data set to answer the questions: (1) How predictably different are islands and rivers, both in terms of genomic location and gene function? (2) Are the adaptive genetic trait loci underlying tadpole growth and development reliably islands, rivers or neither? We found that island and river loci have significant overlap within a contact zone, suggesting that some loci are first islands, and later are predictably converted into rivers. However, gene ontology enrichment analysis showed strong overlap in gene function unique to all island loci, suggesting predictability in overall gene pathways for islands. Genome-wide association study outliers for tadpole development included LPIN3, a lipid metabolism gene potentially involved in climate change adaptation, that is island-like for all three contact zones, but also appears to be introgressing (as a river) across one zone. Taken together, our results suggest that adaptive divergence and introgression may be more complementary forces than currently appreciated.
Collapse
Affiliation(s)
- Paul A Maier
- Department of Biology, San Diego State University, San Diego, California, USA
- Family TreeDNA, Gene by Gene, Houston, Texas, USA
| | - Amy G Vandergast
- Western Ecological Research Center, San Diego Field Station, U.S. Geological Survey, San Diego, California, USA
| | - Andrew J Bohonak
- Department of Biology, San Diego State University, San Diego, California, USA
| |
Collapse
|
4
|
Howe NS, Hale MC, Waters CD, Schaal SM, Shedd KR, Larson WA. Genomic evidence for domestication selection in three hatchery populations of Chinook salmon, Oncorhynchus tshawytscha. Evol Appl 2024; 17:e13656. [PMID: 38357359 PMCID: PMC10866082 DOI: 10.1111/eva.13656] [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: 08/29/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/16/2024] Open
Abstract
Fish hatcheries are widely used to enhance fisheries and supplement declining wild populations. However, substantial evidence suggests that hatchery fish are subject to differential selection pressures compared to their wild counterparts. Domestication selection, or adaptation to the hatchery environment, poses a risk to wild populations if traits specific to success in the hatchery environment have a genetic component and there is subsequent introgression between hatchery and wild fish. Few studies have investigated domestication selection in hatcheries on a genomic level, and even fewer have done so in parallel across multiple hatchery-wild population pairs. In this study, we used low-coverage whole-genome sequencing to investigate signals of domestication selection in three separate hatchery populations of Chinook salmon, Oncorhynchus tshawytscha, after approximately seven generations of divergence from their corresponding wild progenitor populations. We sequenced 192 individuals from populations across Southeast Alaska and estimated genotype likelihoods at over six million loci. We discovered a total of 14 outlier peaks displaying high genetic differentiation (F ST) between hatchery-wild pairs, although no peaks were shared across the three comparisons. Peaks were small (53 kb on average) and often displayed elevated absolute genetic divergence (D xy) and linkage disequilibrium, suggesting some level of domestication selection has occurred. Our study provides evidence that domestication selection can lead to genetic differences between hatchery and wild populations in only a few generations. Additionally, our data suggest that population-specific adaptation to hatchery environments likely occurs through different genetic pathways, even for populations with similar standing genetic variation. These results highlight the need to collect paired genotype-phenotype data to understand how domestication may be affecting fitness and to identify potential management practices that may mitigate genetic risks despite multiple pathways of domestication.
Collapse
Affiliation(s)
- Natasha S. Howe
- Department of BiologyTexas Christian UniversityFort WorthTexasUSA
| | - Matthew C. Hale
- Department of BiologyTexas Christian UniversityFort WorthTexasUSA
| | - Charles D. Waters
- National Oceanographic and Atmospheric Administration, National Marine Fisheries ServiceAlaska Fisheries Science Center, Auke Bay LaboratoriesJuneauAlaskaUSA
| | - Sara M. Schaal
- National Oceanographic and Atmospheric Administration, National Marine Fisheries ServiceAlaska Fisheries Science Center, Auke Bay LaboratoriesJuneauAlaskaUSA
| | - Kyle R. Shedd
- Alaska Department of Fish and Game, Division of Commercial FisheriesGene Conservation LaboratoryAnchorageAlaskaUSA
| | - Wesley A. Larson
- National Oceanographic and Atmospheric Administration, National Marine Fisheries ServiceAlaska Fisheries Science Center, Auke Bay LaboratoriesJuneauAlaskaUSA
| |
Collapse
|
5
|
Blanckaert A, Sriram V, Bank C. In search of the Goldilocks zone for hybrid speciation II: hard times for hybrid speciation? Evolution 2023; 77:2162-2172. [PMID: 37459183 PMCID: PMC10547126 DOI: 10.1093/evolut/qpad125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/24/2023] [Accepted: 06/30/2023] [Indexed: 07/28/2023]
Abstract
Hybridization opens a unique window for observing speciation mechanisms and is a potential engine of speciation. One controversially discussed outcome of hybridization is homoploid hybrid speciation by reciprocal sorting, where a hybrid population maintains a mixed combination of the parental genetic incompatibilities, preventing further gene exchange between the newly formed population and the two parental sources. Previous work showed that, for specific linkage architectures (i.e., the genomic location and order of hybrid incompatibilities), reciprocal sorting could reliably result in hybrid speciation. Yet, the sorting of incompatibilities creates a risk of population extinction. To understand how the demographic consequences of the purging of incompatibilities interact with the formation of a hybrid species, we model an isolated hybrid population resulting from a single admixture event. We study how population size, linkage architecture, and the strength of the incompatibility affect survival of the hybrid population, resolution/purging of the genetic incompatibilities and the probability of observing hybrid speciation. We demonstrate that the extinction risk is highest for intermediately strong hybrid incompatibilities. In addition, the linkage architecture displaying the highest hybrid speciation probabilities changes drastically with population size. Overall, this indicates that population dynamics can strongly affect the outcome of hybridization and the hybrid speciation probability.
Collapse
Affiliation(s)
- Alexandre Blanckaert
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
- cE3c - Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Lisboa, Portugal
| | | | - Claudia Bank
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Euclide PT, Larson WA, Shi Y, Gruenthal K, Christensen KA, Seeb J, Seeb L. Conserved islands of divergence associated with adaptive variation in sockeye salmon are maintained by multiple mechanisms. Mol Ecol 2023. [PMID: 37695544 DOI: 10.1111/mec.17126] [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: 05/09/2023] [Revised: 08/01/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023]
Abstract
Local adaptation is facilitated by loci clustered in relatively few regions of the genome, termed genomic islands of divergence. The mechanisms that create and maintain these islands and how they contribute to adaptive divergence is an active research topic. Here, we use sockeye salmon as a model to investigate both the mechanisms responsible for creating islands of divergence and the patterns of differentiation at these islands. Previous research suggested that multiple islands contributed to adaptive radiation of sockeye salmon. However, the low-density genomic methods used by these studies made it difficult to fully elucidate the mechanisms responsible for islands and connect genotypes to adaptive variation. We used whole genome resequencing to genotype millions of loci to investigate patterns of genetic variation at islands and the mechanisms that potentially created them. We discovered 64 islands, including 16 clustered in four genomic regions shared between two isolated populations. Characterisation of these four regions suggested that three were likely created by structural variation, while one was created by processes not involving structural variation. All four regions were small (< 600 kb), suggesting low recombination regions do not have to span megabases to be important for adaptive divergence. Differentiation at islands was not consistently associated with established population attributes. In sum, the landscape of adaptive divergence and the mechanisms that create it are complex; this complexity likely helps to facilitate fine-scale local adaptation unique to each population.
Collapse
Affiliation(s)
- Peter T Euclide
- Department of Forestry and Natural Resources, Illinois-Indiana Sea Grant, Purdue University, West Lafayette, Indiana, USA
| | - Wesley A Larson
- National Oceanographic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Auke Bay Laboratories, Juneau, Alaska, USA
| | - Yue Shi
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA
| | - Kristen Gruenthal
- Alaska Department of Fish and Game, Juneau, Alaska, USA
- Office of Applied Science, Wisconsin Department of Natural Resources, Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Kris A Christensen
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Jim Seeb
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| | - Lisa Seeb
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, USA
| |
Collapse
|
8
|
Blanckaert A, Sriram V, Bank C. In search of the Goldilocks zone for hybrid speciation II: hard times for hybrid speciation? BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528680. [PMID: 36824868 PMCID: PMC9948988 DOI: 10.1101/2023.02.15.528680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Hybridization opens a unique window for observing speciation mechanisms and is a potential engine of speciation. One controversially discussed outcome of hybridization is homoploid hybrid speciation by reciprocal sorting, where a hybrid population maintains a mixed combination of the parental genetic incompatibilities, preventing further gene exchange between the newly formed population and the two parental sources. Previous work showed that, for specific linkage architectures (i.e., the genomic location and order of hybrid incompatibilities), reciprocal sorting could reliably result in hybrid speciation. Yet, the sorting of incompatibilities creates a risk of population extinction. To understand how demographic consequences of the purging of incompatibilities interact with the formation of a hybrid species, we model an isolated hybrid population resulting from a single admixture event. We study how population size, linkage architecture and the strength of the incompatibility affect survival of the hybrid population, resolution/purging of the genetic incompatibilities and the probability of observing hybrid speciation. We demonstrate that the extinction risk is highest for intermediately strong hybrid incompatibilities. In addition, the linkage architecture displaying the highest hybrid speciation probabilities changes drastically with population size. Overall, this indicates that population dynamics can strongly affect the outcome of hybridization and the hybrid speciation probability.
Collapse
Affiliation(s)
- Alexandre Blanckaert
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, USA
- cE3c - Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Portugal
| | | | - Claudia Bank
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| |
Collapse
|
9
|
Caeiro-Dias G, Brelsford A, Meneses-Ribeiro M, Crochet PA, Pinho C. Hybridization in late stages of speciation: Strong but incomplete genome-wide reproductive isolation and 'large Z-effect' in a moving hybrid zone. Mol Ecol 2023. [PMID: 37316984 DOI: 10.1111/mec.17035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 04/27/2023] [Accepted: 05/12/2023] [Indexed: 06/16/2023]
Abstract
In organisms reproducing sexually, speciation occurs when increasing divergence results in pre- or post-zygotic reproductive isolation between lineages. Studies focusing on reproductive isolation origin in early stages of speciation are common and many rely on genomic scans to infer introgression providing limited information on the genomic architecture of reproductive isolation long-term maintenance. This study analyses a natural hybrid zone between two species in a late stage of speciation. We used ddRADseq genotyping in the contact between Podarcis bocagei and P. carbonelli to examine admixture extent, analyse hybrid zone stability and assess genome-wide variation in selection against introgression. We confirmed strong but incomplete reproductive isolation in a bimodal hybrid zone. New findings revealed population genetic structure within P. carbonelli in the contact zone; geographical and genomic clines analysis suggested strong selection against gene flow, but a relatively small proportion of the loci can introgress, mostly within the narrow contact zone. However, geographical clines revealed that a few introgressed loci show signs of potential positive selection, particularly into P. bocagei. Geographical clines also detected a signal of hybrid zone movement towards P. bocagei distribution. Genomic cline analysis revealed heterogeneous patterns of introgression among loci within the syntopy zone, but the majority maintain a strong association with the genomic background of origin. However, incongruences between both cline approaches were found, potentially driven by confounding effects on genomic clines. Last, an important role of the Z chromosome in reproductive isolation is suggested. Importantly, overall patterns of restricted introgression seem to result from numerous strong intrinsic barriers across the genome.
Collapse
Affiliation(s)
- Guilherme Caeiro-Dias
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France
| | - Alan Brelsford
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Biology Department, University of California Riverside, Riverside, California, USA
| | - Mariana Meneses-Ribeiro
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Pierre-André Crochet
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Catarina Pinho
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| |
Collapse
|
10
|
Cheng H, Zhang Z, Wen J, Lenstra JA, Heller R, Cai Y, Guo Y, Li M, Li R, Li W, He S, Wang J, Shao J, Song Y, Zhang L, Billah M, Wang X, Liu M, Jiang Y. Long divergent haplotypes introgressed from wild sheep are associated with distinct morphological and adaptive characteristics in domestic sheep. PLoS Genet 2023; 19:e1010615. [PMID: 36821549 PMCID: PMC9949681 DOI: 10.1371/journal.pgen.1010615] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 01/13/2023] [Indexed: 02/24/2023] Open
Abstract
The worldwide sheep population comprises more than 1000 breeds. Together, these exhibit a considerable morphological diversity, which has not been extensively investigated at the molecular level. Here, we analyze whole-genome sequencing individuals of 1,098 domestic sheep from 154 breeds, and 69 wild sheep from seven Ovis species. On average, we detected 6.8%, 1.0% and 0.2% introgressed sequence in domestic sheep originating from Iranian mouflon, urial and argali, respectively, with rare introgressions from other wild species. Interestingly, several introgressed haplotypes contributed to the morphological differentiations across sheep breeds, such as a RXFP2 haplotype from Iranian mouflon conferring the spiral horn trait, a MSRB3 haplotype from argali strongly associated with ear morphology, and a VPS13B haplotype probably originating from urial and mouflon possibly associated with facial traits. Our results reveal that introgression events from wild Ovis species contributed to the high rate of morphological differentiation in sheep breeds, but also to individual variation within breeds. We propose that long divergent haplotypes are a ubiquitous source of phenotypic variation that allows adaptation to a variable environment, and that these remain intact in the receiving population probably due to reduced recombination.
Collapse
Affiliation(s)
- Hong Cheng
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Zhuangbiao Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Jiayue Wen
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Johannes A. Lenstra
- Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Rasmus Heller
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yudong Cai
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Yingwei Guo
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Ming Li
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Ran Li
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Wenrong Li
- Key Laboratory of Ruminant Genetics, Breeding & Reproduction, Ministry of Agriculture, China
- Key Laboratory of Animal Biotechnology of Xinjiang, Institute of Biotechnology, Xinjiang Academy of Animal Science, Urumqi, Xinjiang, China
| | - Sangang He
- Key Laboratory of Ruminant Genetics, Breeding & Reproduction, Ministry of Agriculture, China
- Key Laboratory of Animal Biotechnology of Xinjiang, Institute of Biotechnology, Xinjiang Academy of Animal Science, Urumqi, Xinjiang, China
| | - Jintao Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Junjie Shao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Yuxuan Song
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Lei Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Masum Billah
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Xihong Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
| | - Mingjun Liu
- Key Laboratory of Ruminant Genetics, Breeding & Reproduction, Ministry of Agriculture, China
- Key Laboratory of Animal Biotechnology of Xinjiang, Institute of Biotechnology, Xinjiang Academy of Animal Science, Urumqi, Xinjiang, China
- * E-mail: (ML); (YJ)
| | - Yu Jiang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
- * E-mail: (ML); (YJ)
| |
Collapse
|
11
|
Sun N, Yang L, Tian F, Zeng H, He Z, Zhao K, Wang C, Meng M, Feng C, Fang C, Lv W, Bo J, Tang Y, Gan X, Peng Z, Chen Y, He S. Sympatric or micro-allopatric speciation in a glacial lake? Genomic islands support neither. Natl Sci Rev 2022; 9:nwac291. [PMID: 36778108 PMCID: PMC9905650 DOI: 10.1093/nsr/nwac291] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Apparent cases of sympatric speciation may actually be due to micro-allopatric or micro-parapatric speciation. One way to distinguish between these models is to examine the existence and nature of genomic islands of divergence, wherein divergent DNA segments are interspersed with low-divergence segments. Such islands should be rare or absent under micro-allopatric speciation but common in cases of speciation with gene flow. Sympatric divergence of endemic fishes is known from isolated saline, crater, postglacial, and ancient lakes. Two morphologically distinct cyprinid fishes, Gymnocypris eckloni scoliostomus (GS) and G. eckloni eckloni (GE), in a small glacial lake on the Qinghai-Tibet Plateau, Lake Sunmcuo, match the biogeographic criteria of sympatric speciation. In this study, we examined genome-wide variation in 46 individuals from these two groups. The divergence time between the GS and GE lineages was estimated to be 20-60 Kya. We identified 54 large genomic islands (≥100 kb) of speciation, which accounted for 89.4% of the total length of all genomic islands. These islands harboured divergent genes related to olfactory receptors and olfaction signals that may play important roles in food selection and assortative mating in fishes. Although the genomic islands clearly indicated speciation with gene flow and rejected micro-allopatric speciation, they were too large to support the hypothesis of sympatric speciation. Theoretical and recent empirical studies suggested that continual gene flow in sympatry should give rise to many small genomic islands (as small as a few kilobases in size). Thus, the observed pattern is consistent with the extensive evidence on parapatric speciation, in which adjacent habitats facilitate divergent selection but also permit gene flow during speciation. We suggest that many, if not most, of the reported cases of sympatric speciation are likely to be micro-parapatric speciation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Cheng Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Minghui Meng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Chenguang Feng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710129, China
| | - Chengchi Fang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wenqi Lv
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Bo
- Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongtao Tang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
| | - Xiaoni Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Zuogang Peng
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Southwest University School of Life Sciences, Chongqing 400700, China
| | | | | |
Collapse
|
12
|
Luo X, Zhou H, Cao D, Yan F, Chen P, Wang J, Woeste K, Chen X, Fei Z, An H, Malvolti M, Ma K, Liu C, Ebrahimi A, Qiao C, Ye H, Li M, Lu Z, Xu J, Cao S, Zhao P. Domestication and selection footprints in Persian walnuts (Juglans regia). PLoS Genet 2022; 18:e1010513. [PMID: 36477175 PMCID: PMC9728896 DOI: 10.1371/journal.pgen.1010513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
Walnut (Juglans) species are economically important hardwood trees cultivated worldwide for both edible nuts and high-quality wood. Broad-scale assessments of species diversity, evolutionary history, and domestication are needed to improve walnut breeding. In this study, we sequenced 309 walnut accessions from around the world, including 55 Juglans relatives, 98 wild Persian walnuts (J. regia), 70 J. regia landraces, and 86 J. regia cultivars. The phylogenetic tree indicated that J. regia samples (section Dioscaryon) were monophyletic within Juglans. The core areas of genetic diversity of J. regia germplasm were southwestern China and southern Asia near the Qinghai-Tibet Plateau and the Himalayas, and the uplift of the Himalayas was speculated to be the main factor leading to the current population dynamics of Persian walnut. The pattern of genomic variation in terms of nucleotide diversity, linkage disequilibrium, single nucleotide polymorphisms, and insertions/deletions revealed the domestication and selection footprints in Persian walnut. Selective sweep analysis, GWAS, and expression analysis further identified two transcription factors, JrbHLH and JrMYB6, that influence the thickness of the nut diaphragm as loci under selection during domestication. Our results elucidate the domestication and selection footprints in Persian walnuts and provide a valuable resource for the genomics-assisted breeding of this important crop.
Collapse
Affiliation(s)
- Xiang Luo
- College of Agriculture, Henan University, Kaifeng, Henan, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Huijuan Zhou
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
- Xi’an Botanical Garden of Shaanxi Province, Xi’an, China
- College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
| | - Da Cao
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
| | - Feng Yan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Pengpeng Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Jiangtao Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Keith Woeste
- USDA Forest Service Hardwood Tree Improvement and Regeneration Center (HTIRC), Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, United States of America
| | - Xin Chen
- Shandong Institute of Pomology, National Germplasm Repository of Walnut and Chestnut, Tai’an, China
| | - Zhangjun Fei
- Boyce Thompson Institute for Plant Research, US Department of Agriculture (USDA) Robert W. Holley Center for Agriculture and Health, Cornell University, Ithaca, New York, United States of America
| | - Hong An
- Bioinformatics and Analytics Core, University of Missouri, Columbia, Missouri, United States of America
| | - Maria Malvolti
- Research Institute on Terrestrial Ecosystems, National Research Council, Porano, Terni, Italy
| | - Kai Ma
- Xinjiang Academy of Agricultural Sciences, Urumqi, China
| | - Chaobin Liu
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
| | - Aziz Ebrahimi
- USDA Forest Service Hardwood Tree Improvement and Regeneration Center (HTIRC), Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, United States of America
| | - Chengkui Qiao
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Hang Ye
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Mengdi Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Zhenhua Lu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Jiabao Xu
- BGI Genomics, BGI-Shenzhen, Shenzhen, China
- * E-mail: (JX); (SC); (PZ)
| | - Shangying Cao
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- * E-mail: (JX); (SC); (PZ)
| | - Peng Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
- * E-mail: (JX); (SC); (PZ)
| |
Collapse
|
13
|
Weist P, Jentoft S, Tørresen OK, Schade FM, Pampoulie C, Krumme U, Hanel R. The role of genomic signatures of directional selection and demographic history in the population structure of a marine teleost with high gene flow. Ecol Evol 2022; 12:e9602. [PMID: 36514551 PMCID: PMC9731920 DOI: 10.1002/ece3.9602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 11/14/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022] Open
Abstract
Recent studies have uncovered patterns of genomic divergence in marine teleosts where panmixia due to high gene flow has been the general paradigm. These signatures of divergent selection are often impacted by structural variants, acting as "supergenes" facilitating local adaptation. The highly dispersing European plaice (Pleuronectes platessa)-in which putative structural variants (i.e., inversions) have been identified-has successfully colonized the brackish water ecosystem of the Baltic Sea. Thus, the species represents an ideal opportunity to investigate how the interplay of gene flow, structural variants, natural selection, past demographic history, and gene flow impacts on population (sub)structuring in marine systems. Here, we report on the generation of an annotated draft plaice genome assembly in combination with population sequencing data-following the salinity gradient from the Baltic Sea into the North Sea together with samples from Icelandic waters-to illuminate genome-wide patterns of divergence. Neutral markers pointed at large-scale panmixia across the European continental shelf associated with high gene flow and a common postglacial colonization history of shelf populations. However, based on genome-wide outlier loci, we uncovered signatures of population substructuring among the European continental shelf populations, i.e., suggesting signs of ongoing selection. Genome-wide selection analyses (xp-EHH) and the identification of genes within genomic regions of recent selective sweeps-overlapping with the outlier loci-suggest that these represent the signs of divergent selection. Our findings provide support for genomic divergence driven by local adaptation in the face of high gene flow and elucidate the relative importance of demographic history versus adaptive divergence in shaping the contemporary population genetic structure of a marine teleost. The role of the putative inversion(s) in the substructuring-and potentially ongoing adaptation-was seemingly not substantial.
Collapse
Affiliation(s)
- Peggy Weist
- Thünen Institute of Fisheries EcologyBremerhavenGermany
| | - Sissel Jentoft
- Department of Biosciences, Centre for Ecological and Evolutionary SynthesisUniversity of OsloOsloNorway
| | - Ole K. Tørresen
- Department of Biosciences, Centre for Ecological and Evolutionary SynthesisUniversity of OsloOsloNorway
| | | | | | - Uwe Krumme
- Thünen Institute of Baltic Sea FisheriesRostockGermany
| | | |
Collapse
|
14
|
Spies I, Tarpey C, Kristiansen T, Fisher M, Rohan S, Hauser L. Genomic differentiation in Pacific cod using Pool-Seq. Evol Appl 2022; 15:1907-1924. [PMID: 36426128 PMCID: PMC9679252 DOI: 10.1111/eva.13488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 09/05/2022] [Accepted: 09/21/2022] [Indexed: 11/28/2022] Open
Abstract
Patterns of genetic differentiation across the genome can provide insight into selective forces driving adaptation. We used pooled whole genome sequencing, gene annotation, and environmental covariates to evaluate patterns of genomic differentiation and to investigate mechanisms responsible for divergence among proximate Pacific cod (Gadus macrocephalus) populations from the Bering Sea and Aleutian Islands and more distant Washington Coast cod. Samples were taken from eight spawning locations, three of which were replicated to estimate consistency in allele frequency estimation. A kernel smoothing moving weighted average of relative divergence (F ST) identified 11 genomic islands of differentiation between the Aleutian Islands and Bering Sea samples. In some islands of differentiation, there was also elevated absolute divergence (d XY) and evidence for selection, despite proximity and potential for gene flow. Similar levels of absolute divergence (d XY) but roughly double the relative divergence (F ST) were observed between the distant Bering Sea and Washington Coast samples. Islands of differentiation were much smaller than the four large inversions among Atlantic cod ecotypes. Islands of differentiation between the Bering Sea and Aleutian Island were associated with SNPs from five vision system genes, which can be associated with feeding, predator avoidance, orientation, and socialization. We hypothesize that islands of differentiation between Pacific cod from the Bering Sea and Aleutian Islands provide evidence for adaptive differentiation despite gene flow in this commercially important marine species.
Collapse
Affiliation(s)
- Ingrid Spies
- Resource Ecology and Fisheries Management DivisionAlaska Fisheries Science CenterSeattleWashingtonUSA
| | - Carolyn Tarpey
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | | | - Mary Fisher
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Sean Rohan
- Resource Assessment and Conservation Engineering DivisionAlaska Fisheries Science CenterSeattleWashingtonUSA
| | - Lorenz Hauser
- Resource Ecology and Fisheries Management DivisionAlaska Fisheries Science CenterSeattleWashingtonUSA
| |
Collapse
|
15
|
Wang L, Liu S, Yang Y, Meng Z, Zhuang Z. Linked selection, differential introgression and recombination rate variation promote heterogeneous divergence in a pair of yellow croakers. Mol Ecol 2022; 31:5729-5744. [PMID: 36111361 PMCID: PMC9828471 DOI: 10.1111/mec.16693] [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: 04/24/2021] [Accepted: 09/06/2022] [Indexed: 01/13/2023]
Abstract
Understanding the mechanisms underlying heterogeneous genomic divergence is of particular interest in evolutionary biology. Highly differentiated genomic regions, known as genomic islands, often evolve between diverging lineages. These genomic islands may be related to selection promoting adaptation or reproductive isolation. Based on whole genome assembly and genome-wide RAD sequencing in a pair of yellow croakers (genus: Larimichthys), we investigated the evolutionary processes shaping genomic landscapes of divergence. Demographic modelling indicated that the two species diverged following a secondary contact scenario, where differential introgression and linked selection were suggested to be involved in heterogeneous genomic divergence. We identified reduced recombination rate in genomic islands and a relatively good conservation of both genetic diversity and recombination landscapes between species, which highlight the roles of linked selection and recombination rate variation in promoting heterogeneous divergence in the common ancestral lineage of the two species. In addition, we found a positive correlation between differentiation (FST ) and absolute sequence divergence (Dxy ), and elevated Dxy in genomic islands, indicating that the genomic landscape of divergence was not shaped by linked selection alone. Restricted gene flow in highly differentiated regions has probably remodelled the landscape of heterogeneous genomic divergence. This study highlights that highly differentiated genomic regions can also arise from a combination of linked selection and differential gene flow in interaction with varying recombination rates.
Collapse
Affiliation(s)
- Le Wang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina,Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research LinkNational University of SingaporeSingapore CitySingapore
| | - Shufang Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences & Function Laboratory for Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
| | - Yang Yang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Zining Meng
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life SciencesSun Yat‐sen UniversityGuangzhouChina,Southern Laboratory of Ocean Science and EngineeringZhuhaiChina
| | - Zhimeng Zhuang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences & Function Laboratory for Marine Biology and BiotechnologyQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
| |
Collapse
|
16
|
Shi Y, Homola JJ, Euclide PT, Isermann DA, Caroffino D, McPhee MV, Larson WA. High-density genomic data reveal fine-scale population structure and pronounced islands of adaptive divergence in lake whitefish ( Coregonus clupeaformis) from Lake Michigan. Evol Appl 2022; 15:1776-1791. [PMID: 36426119 PMCID: PMC9679245 DOI: 10.1111/eva.13475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 08/12/2022] [Accepted: 08/14/2022] [Indexed: 09/08/2024] Open
Abstract
Understanding patterns of genetic structure and adaptive variation in natural populations is crucial for informing conservation and management. Past genetic research using 11 microsatellite loci identified six genetic stocks of lake whitefish (Coregonus clupeaformis) within Lake Michigan, USA. However, ambiguity in genetic stock assignments suggested those neutral microsatellite markers did not provide adequate power for delineating lake whitefish stocks in this system, prompting calls for a genomics approach to investigate stock structure. Here, we generated a dense genomic dataset to characterize population structure and investigate patterns of neutral and adaptive genetic diversity among lake whitefish populations in Lake Michigan. Using Rapture sequencing, we genotyped 829 individuals collected from 17 baseline populations at 197,588 SNP markers after quality filtering. Although the overall pattern of genetic structure was similar to the previous microsatellite study, our genomic data provided several novel insights. Our results indicated a large genetic break between the northwestern and eastern sides of Lake Michigan, and we found a much greater level of population structure on the eastern side compared to the northwestern side. Collectively, we observed five genomic islands of adaptive divergence on five different chromosomes. Each island displayed a different pattern of population structure, suggesting that combinations of genotypes at these adaptive regions are facilitating local adaptation to spatially heterogenous selection pressures. Additionally, we identified a large linkage disequilibrium block of ~8.5 Mb on chromosome 20 that is suggestive of a putative inversion but with a low frequency of the minor haplotype. Our study provides a comprehensive assessment of population structure and adaptive variation that can help inform the management of Lake Michigan's lake whitefish fishery and highlights the utility of incorporating adaptive loci into fisheries management.
Collapse
Affiliation(s)
- Yue Shi
- College of Fisheries and Ocean SciencesUniversity of Alaska FairbanksJuneauAlaskaUSA
- Wisconsin Cooperative Fishery Research Unit, College of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsinUSA
| | - Jared J. Homola
- U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit, College of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsinUSA
| | - Peter T. Euclide
- Wisconsin Cooperative Fishery Research Unit, College of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsinUSA
| | - Daniel A. Isermann
- U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit, College of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsinUSA
| | - David C. Caroffino
- Michigan Department of Natural ResourcesCharlevoix Research StationCharlevoixMichiganUSA
| | - Megan V. McPhee
- College of Fisheries and Ocean SciencesUniversity of Alaska FairbanksJuneauAlaskaUSA
| | - Wesley A. Larson
- U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit, College of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsinUSA
- National Marine Fisheries Service, Alaska Fisheries Science Center, Auke Bay LaboratoriesNational Oceanic and Atmospheric AdministrationJuneauAlaskaUSA
| |
Collapse
|
17
|
Reproductive isolation via polygenic local adaptation in sub-divided populations: Effect of linkage disequilibria and drift. PLoS Genet 2022; 18:e1010297. [PMID: 36048903 PMCID: PMC9473638 DOI: 10.1371/journal.pgen.1010297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 09/14/2022] [Accepted: 06/16/2022] [Indexed: 12/01/2022] Open
Abstract
This paper considers how polygenic local adaptation and reproductive isolation between hybridizing populations is influenced by linkage disequilibria (LD) between loci, in scenarios where both gene flow and genetic drift counteract selection. It shows that the combined effects of multi-locus LD and genetic drift on allele frequencies at selected loci and on heterozygosity at neutral loci are predicted accurately by incorporating (deterministic) effective migration rates into the diffusion approximation (for selected loci) and into the structured coalescent (for neutral loci). Theoretical approximations are tested against individual-based simulations and used to investigate conditions for the maintenance of local adaptation on an island subject to one-way migration from a differently adapted mainland, and in an infinite-island population with two habitats under divergent selection. The analysis clarifies the conditions under which LD between sets of locally deleterious alleles allows these to be collectively eliminated despite drift, causing sharper and (under certain conditions) shifted migration thresholds for loss of adaptation. Local adaptation also has counter-intuitive effects on neutral (relative) divergence: FST is highest for a pair of subpopulations belonging to the same (rare) habitat, despite the lack of reproductive isolation between them. Environmental adaptation often involves spatially heterogeneous selection at many genetic loci. Thus, the evolutionary consequences of hybridisation between populations adapted to different environments depend on the coupled dynamics of multiple loci under selection, migration and genetic drift, making them challenging to predict. Here, I introduce theoretical approximations that accurately capture the effect of such coupling on allele frequencies at individual loci, while also accounting for the stochastic effects of genetic drift. I then use these approximations to study hybridisation in a metapopulation consisting of many interconnected subpopulations, where each subpopulation belongs to one of two habitats under divergent selection. The analysis clarifies how subpopulations belonging to a rare habitat can maintain local adaptation despite high levels of migration if net selection against multi-locus genotypes is stronger than a threshold which depends on the relative abundances of the two habitats. Further, local adaptation in a metapopulation can significantly elevate FST between subpopulations belonging to the same habitat, even though these are not reproductively isolated. These findings highlight the importance of carefully considering the genetic architecture and spatial context of divergence when interpreting patterns of genomic differentiation between speciating populations.
Collapse
|
18
|
Olivares‐Zambrano D, Daane J, Hyde J, Sandel MW, Aguilar A. Speciation genomics and the role of depth in the divergence of rockfishes ( Sebastes) revealed through Pool-seq analysis of enriched sequences. Ecol Evol 2022; 12:e9341. [PMID: 36188524 PMCID: PMC9502067 DOI: 10.1002/ece3.9341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/22/2022] [Accepted: 08/30/2022] [Indexed: 11/07/2022] Open
Abstract
Speciation in the marine environment is challenged by the wide geographic distribution of many taxa and potential for high rates of gene flow through larval dispersal mechanisms. Depth has recently been proposed as a potential driver of ecological divergence in fishes, and yet it is unclear how adaptation along these gradients' shapes genomic divergence. The genus Sebastes contains numerous species pairs that are depth-segregated and can provide a better understanding of the mode and tempo of genomic diversification. Here, we present exome data on two species pairs of rockfishes that are depth-segregated and have different degrees of divergence: S. chlorostictus-S. rosenblatti and S. crocotulus-S. miniatus. We were able to reliably identify "islands of divergence" in the species pair with more recent divergence (S. chlorostictus-S. rosenblatti) and discovered a number of genes associated with neurosensory function, suggesting a role for this pathway in the early speciation process. We also reconstructed demographic histories of divergence and found the best supported model was isolation followed by asymmetric secondary contact for both species pairs. These results suggest past ecological/geographic isolation followed by asymmetric secondary contact of deep to shallow species. Our results provide another example of using rockfish as a model for studying speciation and support the role of depth as an important mechanism for diversification in the marine environment.
Collapse
Affiliation(s)
- Daniel Olivares‐Zambrano
- Department of Biological SciencesCalifornia State University Los AngelesLos AngelesCaliforniaUSA
- Present address:
Department of Marine and Environmental BiologyUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | - Jacob Daane
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| | - John Hyde
- National Oceanic and Atmospheric Administration, National Marine Fisheries ServiceNational Marine Fisheries ServiceSouthwest Fisheries Science CenterLa JollaCaliforniaUSA
| | - Michael W. Sandel
- Biological and Environmental SciencesUniversity of West AlabamaLivingstonAlabamaUSA
- Department of WIldlifeFisheries, and Aquaculture, Mississippi State UniversityMississippi StateMississippiUSA
| | - Andres Aguilar
- Department of Biological SciencesCalifornia State University Los AngelesLos AngelesCaliforniaUSA
| |
Collapse
|
19
|
Kvistad L, Falk S, Austin L. Widespread genomic signatures of reproductive isolation and sex-specific selection in the Eastern Yellow Robin, Eopsaltria australis. G3 GENES|GENOMES|GENETICS 2022; 12:6605223. [PMID: 35686912 PMCID: PMC9438485 DOI: 10.1093/g3journal/jkac145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
How new species evolve is one of the most fundamental questions in biology. Population divergence, which may lead to speciation, may be occurring in the Eastern Yellow Robin, a common passerine that lives along the eastern coast of Australia. This species is composed of 2 parapatric lineages that have highly divergent mitochondrial DNA; however, similar levels of divergence have not been observed in the nuclear genome. Here we re-examine the nuclear genomes of these mitolineages to test potential mechanisms underlying the discordance between nuclear and mitochondrial divergence. We find that nuclear admixture occurs in a narrow hybrid zone, although the majority of markers across the genome show evidence of reproductive isolation between populations of opposing mitolineages. There is an 8 MB section of a previously identified putative neo-sex chromosome that is highly diverged between allopatric but not parapatric populations, which may be the result of a chromosomal inversion. The neo-sex chromosomal nature of this region, as well as the geographic patterns in which it exhibits divergence, suggest it is unlikely to be contributing to reproductive isolation through mitonuclear incompatibilities as reported in earlier studies. In addition, there are sex differences in the number of markers that are differentiated between populations of opposite mitolineages, with greater differentiation occurring in females, which are heterozygous, than males. These results suggest that, despite the absence of previously observed assortative mating, mitolineages of Eastern Yellow Robin experience at least some postzygotic isolation from each other, in a pattern consistent with Haldane’s Rule.
Collapse
Affiliation(s)
- Lynna Kvistad
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
| | - Stephanie Falk
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
- Deep Sequencing Facility, Max Planck Institute of Immunobiology and Epigenetics , Freiburg D-79108, Germany
| | - Lana Austin
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
| |
Collapse
|
20
|
Brachmann MK, Parsons K, Skúlason S, Gaggiotti O, Ferguson M. Variation in the genomic basis of parallel phenotypic and ecological divergence in benthic and pelagic morphs of Icelandic Arctic charr (Salvelinus alpinus). Mol Ecol 2022; 31:4688-4706. [PMID: 35861579 DOI: 10.1111/mec.16625] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 06/22/2022] [Accepted: 07/06/2022] [Indexed: 11/28/2022]
Abstract
Sympatric adaptive phenotypic divergence should be underlain by genomic differentiation between sub-populations. When divergence drives similar patterns of phenotypic and ecological variation within species we expect evolution to draw on common allelic variation. We investigated divergence histories and genomic signatures of adaptive divergence between benthic and pelagic morphs of Icelandic Arctic charr. Divergence histories for each of four populations were reconstructed using coalescent modelling and 14,187 single nucleotide polymorphisms. Sympatric divergence with continuous gene flow was supported in two populations while allopatric divergence with secondary contact was supported in one population; we could not differentiate between demographic models in the fourth population. We detected parallel patterns of phenotypic divergence along benthic-pelagic evolutionary trajectories among populations. Patterns of genomic differentiation between benthic and pelagic morphs were characterized by outlier loci in many narrow peaks of differentiation throughout the genome, which may reflect the eroding effects of gene flow on nearby neutral loci. We then used genome-wide association analyses to relate both phenotypic (body shape and size) and ecological (carbon and nitrogen stable isotopes) variation to patterns of genomic differentiation. Many peaks of genomic differentiation were associated with phenotypic and ecological variation in the three highly divergent populations, suggesting a genomic basis for adaptive divergence. We detected little evidence for a parallel genomic basis of differentiation as most regions and outlier loci were not shared among populations. Our results show that adaptive divergence can have varied genomic consequences in populations with relatively recent common origins, similar divergence histories, and parallel phenotypic divergence.
Collapse
Affiliation(s)
| | - Kevin Parsons
- Institute of Biodiversity, Animal Health and Comparative Medicine, School of Life Science, University of Glasgow, Glasgow, UK
| | - Skúli Skúlason
- Department of Aquaculture and Fish Biology, Hólar University, Saudárkrókur, Iceland.,Icelandic Museum of Natural History, Reykjavik, Iceland
| | - Oscar Gaggiotti
- School of biology, Scottish Oceans Institute, University of St. Andrews, St. Andrews, UK
| | - Moira Ferguson
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
21
|
Wang G, Lai H, Bi S, Guo D, Zhao X, Chen X, Liu S, Liu X, Su Y, Yi H, Li G. ddRAD-Seq reveals evolutionary insights into population differentiation and the cryptic phylogeography of Hyporhamphus intermedius in Mainland China. Ecol Evol 2022; 12:e9053. [PMID: 35813915 PMCID: PMC9251877 DOI: 10.1002/ece3.9053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 05/28/2022] [Accepted: 06/08/2022] [Indexed: 11/12/2022] Open
Abstract
Species differentiation and local adaptation in heterogeneous environments have attracted much attention, although little is known about the mechanisms involved. Hyporhamphus intermedius is an anadromous, brackish-water halfbeak that is widely distributed in coastal areas and hyperdiverse freshwater systems in China, making it an interesting model for research on phylogeography and local adaptation. Here, 156 individuals were sampled at eight sites from heterogeneous aquatic habitats to examine environmental and genetic contributions to phenotypic divergence. Using double-digest restriction-site-associated DNA sequencing (ddRAD-Seq) in the specimens from the different watersheds, 5498 single nucleotide polymorphisms (SNPs) were found among populations, with obvious population differentiation. We find that present-day Mainland China populations are structured into distinct genetic clusters stretching from southern and northern ancestries, mirroring geography. Following a transplant event in Plateau Lakes, there were virtually no variations of genetic diversity occurred in two populations, despite the fact two main splits were unveiled in the demographic history. Additionally, dorsal, and anal fin traits varied widely between the southern group and the others, which highlighted previously unrecognized lineages. We then explore genotype-phenotype-environment associations and predict candidate loci. Subgroup ranges appeared to correspond to geographic regions with heterogeneous hydrological factors, indicating that these features are likely important drivers of diversification. Accordingly, we conclude that genetic and phenotypic polymorphism and a moderate amount of genetic differentiation occurred, which might be ascribed to population subdivision, and the impact of abiotic factors.
Collapse
Affiliation(s)
- Gongpei Wang
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic CenterSun Yat‐Sen UniversityGuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Han Lai
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Sheng Bi
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Dingli Guo
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Xiaopin Zhao
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Xiaoli Chen
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Shuang Liu
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Xuange Liu
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Yuqin Su
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Huadong Yi
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| | - Guifeng Li
- Guangdong Province Key Laboratory for Aquatic Economic AnimalsState Key Laboratory of BiocontrolSchool of Life SciencesSun Yat‐Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory (Zhuhai)GuangzhouChina
- Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic FishGuangzhouChina
| |
Collapse
|
22
|
Perfect association between spatial swarm segregation and the X-chromosome speciation island in hybridizing Anopheles coluzzii and Anopheles gambiae populations. Sci Rep 2022; 12:10800. [PMID: 35750745 PMCID: PMC9232630 DOI: 10.1038/s41598-022-14865-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/14/2022] [Indexed: 11/08/2022] Open
Abstract
The sibling species An. coluzzii and An. gambiae s.s. are major malaria vectors thought to be undergoing sympatric speciation with gene flow. In the absence of intrinsic post-zygotic isolation between the two taxa, speciation is thought possible through the association of assortative mating and genomic regions protected from gene flow by recombination suppression. Such genomic islands of speciation have been described in pericentromeric regions of the X, 2L and 3L chromosomes. Spatial swarm segregation plays a major role in assortative mating between sympatric populations of the two species and, given their importance for speciation, genes responsible for such pre-mating reproductive barriers are expected to be protected within divergence islands. In this study 2063 male and 266 female An. coluzzii and An. gambiae s.s. individuals from natural swarms in Burkina Faso, West Africa were sampled. These were genotyped at 16 speciation island SNPs, and characterized as non-hybrid individuals, F1 hybrids or recombinant F1+n backcrossed individuals. Their genotypes at each speciation island were associated with their participation in An. coluzzii and An. gambiae-like swarms. Despite extensive introgression between the two species, the X-island genotype of non-hybrid individuals (37.6%), F1 hybrids (0.1%) and F1+n recombinants (62.3%) of either sex perfectly associated to each swarm type. Associations between swarm type and the 3L and 2L speciation islands were weakened or broken down by introgression. The functional demonstration of a close association between spatial segregation behaviour and the X speciation island lends further support to sympatric speciation models facilitated by pericentric recombination suppression in this important species complex.
Collapse
|
23
|
Li Q, Lindtke D, Rodríguez-Ramírez C, Kakioka R, Takahashi H, Toyoda A, Kitano J, Ehrlich RL, Chang Mell J, Yeaman S. Local Adaptation and the Evolution of Genome Architecture in Threespine Stickleback. Genome Biol Evol 2022; 14:6589818. [PMID: 35594844 PMCID: PMC9178229 DOI: 10.1093/gbe/evac075] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2022] [Indexed: 12/11/2022] Open
Abstract
Theory predicts that local adaptation should favor the evolution of a concentrated genetic architecture, where the alleles driving adaptive divergence are tightly clustered on chromosomes. Adaptation to marine versus freshwater environments in threespine stickleback has resulted in an architecture that seems consistent with this prediction: divergence among populations is mainly driven by a few genomic regions harboring multiple quantitative trait loci for environmentally adapted traits, as well as candidate genes with well-established phenotypic effects. One theory for the evolution of these "genomic islands" is that rearrangements remodel the genome to bring causal loci into tight proximity, but this has not been studied explicitly. We tested this theory using synteny analysis to identify micro- and macro-rearrangements in the stickleback genome and assess their potential involvement in the evolution of genomic islands. To identify rearrangements, we conducted a de novo assembly of the closely related tubesnout (Aulorhyncus flavidus) genome and compared this to the genomes of threespine stickleback and two other closely related species. We found that small rearrangements, within-chromosome duplications, and lineage-specific genes (LSGs) were enriched around genomic islands, and that all three chromosomes harboring large genomic islands have experienced macro-rearrangements. We also found that duplicates and micro-rearrangements are 9.9× and 2.9× more likely to involve genes differentially expressed between marine and freshwater genotypes. While not conclusive, these results are consistent with the explanation that strong divergent selection on candidate genes drove the recruitment of rearrangements to yield clusters of locally adaptive loci.
Collapse
Affiliation(s)
- Qiushi Li
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Canada T2N 1N4
| | - Dorothea Lindtke
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Canada T2N 1N4
| | - Carlos Rodríguez-Ramírez
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Ryo Kakioka
- Tropical Biosphere Research Center, University of the Ryukyus, Nishihara, Nakagami-gun, Okinawa 903-0213, Japan
| | - Hiroshi Takahashi
- National Fisheries University, 2-7-1 Nagata-honmachi, Shimonoseki, Yamaguchi 759-6595, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Jun Kitano
- Ecological Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Rachel L Ehrlich
- Department of Microbiology & Immunology, Drexel University College of Medicine, Philadelphia 19102, PA, USA
| | - Joshua Chang Mell
- Department of Microbiology & Immunology, Drexel University College of Medicine, Philadelphia 19102, PA, USA
| | - Sam Yeaman
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Canada T2N 1N4
| |
Collapse
|
24
|
Bendall EE, Bagley RK, Sousa VC, Linnen CR. Faster-haplodiploid evolution under divergence-with-gene-flow: simulations and empirical data from pine-feeding hymenopterans. Mol Ecol 2022; 31:2348-2366. [PMID: 35231148 DOI: 10.1111/mec.16410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/10/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022]
Abstract
Although haplodiploidy is widespread in nature, the evolutionary consequences of this mode of reproduction are not well characterized. Here, we examine how genome-wide hemizygosity and a lack of recombination in haploid males affects genomic differentiation in populations that diverge via natural selection while experiencing gene flow. First, we simulated diploid and haplodiploid "genomes" (500-kb loci) evolving under an isolation-with-migration model with mutation, drift, selection, migration, and recombination; and examined differentiation at neutral sites both tightly and loosely linked to a divergently selected site. So long as there is divergent selection and migration, sex-limited hemizygosity and recombination cause elevated differentiation (i.e., produce a "faster-haplodiploid effect") in haplodiploid populations relative to otherwise equivalent diploid populations, for both recessive and codominant mutations. Second, we used genome-wide SNP data to model divergence history and describe patterns of genomic differentiation between sympatric populations of Neodiprion lecontei and N. pinetum, a pair of pine sawfly species (order: Hymenoptera; family: Diprionidae) that are specialized on different pine hosts. These analyses support a history of continuous gene exchange throughout divergence and reveal a pattern of heterogeneous genomic differentiation that is consistent with divergent selection on many unlinked loci. Third, using simulations of haplodiploid and diploid populations evolving according to the estimated divergence history of N. lecontei and N. pinetum, we found that divergent selection would lead to higher differentiation in haplodiploids. Based on these results, we hypothesize that haplodiploids undergo divergence-with-gene-flow and sympatric speciation more readily than diploids.
Collapse
Affiliation(s)
- Emily E Bendall
- Department of Biology, University of Kentucky, Lexington, Kentucky, 40506, USA.,Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Robin K Bagley
- Department of Biology, University of Kentucky, Lexington, Kentucky, 40506, USA.,Department of Evolution, Ecology, and Organismal Biology, The Ohio State University at Lima, Lima, OH, 45804, USA
| | - Vitor C Sousa
- CE3C - Centre for Ecology, Evolution and Environmental Changes, Department of Animal Biology, Faculdade de Ciências da Universidade de Lisboa, University of Lisbon, Campo Grande 1749-016, Lisboa, Portugal
| | - Catherine R Linnen
- Department of Biology, University of Kentucky, Lexington, Kentucky, 40506, USA
| |
Collapse
|
25
|
Urban S, Gerwin J, Hulsey CD, Meyer A, Kratochwil CF. The repeated evolution of stripe patterns is correlated with body morphology in the adaptive radiations of East African cichlid fishes. Ecol Evol 2022; 12:e8568. [PMID: 35154652 PMCID: PMC8820146 DOI: 10.1002/ece3.8568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/20/2021] [Accepted: 12/30/2021] [Indexed: 01/01/2023] Open
Abstract
Color patterns are often linked to the behavioral and morphological characteristics of an animal, contributing to the effectiveness of such patterns as antipredatory strategies. Species-rich adaptive radiations, such as the freshwater fish family Cichlidae, provide an exciting opportunity to study trait correlations at a macroevolutionary scale. Cichlids are also well known for their diversity and repeated evolution of color patterns and body morphology. To study the evolutionary dynamics between color patterns and body morphology, we used an extensive dataset of 461 species. A phylogenetic supertree of these species shows that stripe patterns evolved ~70 times independently and were lost again ~30 times. Moreover, stripe patterns show strong signs of correlated evolution with body elongation, suggesting that the stripes' effectiveness as antipredatory strategy might differ depending on the body shape. Using pedigree-based analyses, we show that stripes and body elongation segregate independently, indicating that the two traits are not genetically linked. Their correlation in nature is therefore likely maintained by correlational selection. Lastly, by performing a mate preference assay using a striped CRISPR-Cas9 mutant of a nonstriped species, we show that females do not differentiate between striped CRISPR mutant males and nonstriped wild-type males, suggesting that these patterns might be less important for species recognition and mate choice. In summary, our study suggests that the massive rates of repeated evolution of stripe patterns are shaped by correlational selection with body elongation, but not by sexual selection.
Collapse
Affiliation(s)
- Sabine Urban
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - Jan Gerwin
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - C. Darrin Hulsey
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
- Present address:
School of Biology and Environmental ScienceUniversity College DublinBelfieldIreland
| | - Axel Meyer
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
| | - Claudius F. Kratochwil
- Chair in Zoology and Evolutionary BiologyDepartment of BiologyUniversity of KonstanzKonstanzGermany
- Present address:
Institute of Biotechnology, HiLIFEUniversity of HelsinkiHelsinkiFinland
| |
Collapse
|
26
|
Liu Z, Roesti M, Marques D, Hiltbrunner M, Saladin V, Peichel CL. Chromosomal fusions facilitate adaptation to divergent environments in threespine stickleback. Mol Biol Evol 2021; 39:6462204. [PMID: 34908155 PMCID: PMC8826639 DOI: 10.1093/molbev/msab358] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chromosomal fusions are hypothesized to facilitate adaptation to divergent environments, both by bringing together previously unlinked adaptive alleles and by creating regions of low recombination that facilitate the linkage of adaptive alleles; but, there is little empirical evidence to support this hypothesis. Here, we address this knowledge gap by studying threespine stickleback (Gasterosteus aculeatus), in which ancestral marine fish have repeatedly adapted to freshwater across the northern hemisphere. By comparing the threespine and ninespine stickleback (Pungitius pungitius) genomes to a de novo assembly of the fourspine stickleback (Apeltes quadracus) and an outgroup species, we find two chromosomal fusion events involving the same chromosomes have occurred independently in the threespine and ninespine stickleback lineages. On the fused chromosomes in threespine stickleback, we find an enrichment of quantitative trait loci underlying traits that contribute to marine versus freshwater adaptation. By comparing whole-genome sequences of freshwater and marine threespine stickleback populations, we also find an enrichment of regions under divergent selection on these two fused chromosomes. There is elevated genetic diversity within regions under selection in the freshwater population, consistent with a simulation study showing that gene flow can increase diversity in genomic regions associated with local adaptation and our demographic models showing gene flow between the marine and freshwater populations. Integrating our results with previous studies, we propose that these fusions created regions of low recombination that enabled the formation of adaptative clusters, thereby facilitating freshwater adaptation in the face of recurrent gene flow between marine and freshwater threespine sticklebacks.
Collapse
Affiliation(s)
- Zuyao Liu
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Marius Roesti
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - David Marques
- Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Department of Fish Ecology and Evolution, Centre for Ecology, Evolution, and Biogeochemistry, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Kastanienbaum, Switzerland.,Natural History Museum Basel, Basel, Switzerland
| | - Melanie Hiltbrunner
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Verena Saladin
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Catherine L Peichel
- Division of Evolutionary Ecology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| |
Collapse
|
27
|
Shi Y, Bouska KL, McKinney GJ, Dokai W, Bartels A, McPhee MV, Larson WA. Gene flow influences the genomic architecture of local adaptation in six riverine fish species. Mol Ecol 2021; 32:1549-1566. [PMID: 34878685 DOI: 10.1111/mec.16317] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/15/2021] [Accepted: 12/01/2021] [Indexed: 11/30/2022]
Abstract
Understanding how gene flow influences adaptive divergence is important for predicting adaptive responses. Theoretical studies suggest that when gene flow is high, clustering of adaptive genes in fewer genomic regions would protect adaptive alleles from recombination and thus be selected for, but few studies have tested it with empirical data. Here, we used restriction site-associated sequencing to generate genomic data for six fish species with contrasting life histories from six reaches of the Upper Mississippi River System, USA. We used four differentiation-based outlier tests and three genotype-environment association analyses to define neutral single nucleotide polymorphisms (SNPs) and outlier SNPs that were putatively under selection. We then examined the distribution of outlier SNPs along the genome and investigated whether these SNPs were found in genomic islands of differentiation and inversions. We found that gene flow varied among species, and outlier SNPs were clustered more tightly in species with higher gene flow. The two species with the highest overall FST (0.0303-0.0720) and therefore lowest gene flow showed little evidence of clusters of outlier SNPs, with outlier SNPs in these species spreading uniformly across the genome. In contrast, nearly all outlier SNPs in the species with the lowest FST (0.0003) were found in a single large putative inversion. Two other species with intermediate gene flow (FST ~ 0.0025-0.0050) also showed clustered genomic architectures, with most islands of differentiation clustered on a few chromosomes. Our results provide important empirical evidence to support the hypothesis that increasingly clustered architecture of local adaptation is associated with high gene flow.
Collapse
Affiliation(s)
- Yue Shi
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA.,Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Kristen L Bouska
- U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, USA
| | - Garrett J McKinney
- NRC Research Associateship Program, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
| | - William Dokai
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA.,Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| | - Andrew Bartels
- Long Term Resource Monitoring Program, Wisconsin Department of Natural Resources, La Crosse, Wisconsin, USA
| | - Megan V McPhee
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA
| | - Wesley A Larson
- National Oceanographic and Atmospheric Administration, Auke Bay Laboratories, National Marine Fisheries Service, Alaska Fisheries Science Center, Juneau, Alaska, USA.,U.S. Geological Survey, Wisconsin Cooperative Fishery Research Unit, College of Natural Resources, University of Wisconsin-Stevens Point, Stevens Point, Wisconsin, USA
| |
Collapse
|
28
|
Spies I, Drinan DP, Petrou EL, Spurr R, Tarpey C, Hartinger T, Larson W, Hauser L. Evidence for selection and spatially distinct patterns found in a putative zona pellucida gene in Pacific cod, and implications for management. Ecol Evol 2021; 11:16661-16679. [PMID: 34938464 PMCID: PMC8668774 DOI: 10.1002/ece3.8284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 10/08/2021] [Indexed: 11/11/2022] Open
Abstract
Genetic differentiation has been observed in marine species even when no obvious barriers to gene flow exist, and understanding such differentiation is essential for effective fisheries management. Highly differentiated outlier loci can provide information on how genetic variation might not only contribute to local adaptation but may also be affected by historical demographic events. A locus which aligned to a predicted zona pellucida sperm-binding protein 3 gene (ZP3) in Atlantic cod (Gadus morhua) was previously identified as the highest outlier based on F ST in a RADseq study of Pacific cod (Gadus macrocephalus) across the West Coast of North America. However, because of the limited length of the RAD sequence and restricted geographic area of sampling, no conclusion on the functional significance of the observed variation was possible. In other marine species, ZP3 is involved in reproductive isolation, local adaptation, and has neofunctionalized as an antifreeze gene, and so it may provide important insights in functional population structure of Pacific cod. Here, we sequenced a 544-bp region of ZP3 in 230 Pacific cod collected from throughout their geographic range. We observed striking patterns of spatial structuring of ZP3 haplotypes, with a sharp break near Kodiak, Alaska, USA where populations within ~200 km of each other are nearly fixed for different haplotypes, contrasting a pattern of isolation by distance at other genetic markers in this region (F ST = 0.003). Phylogenetic analysis of ZP3 haplotypes revealed that the more southern haplotypes appear to be ancestral, with the northern haplotype evolving more recently, potentially in response to a novel selective pressure as Pacific cod recolonized northern latitudes after glaciation. The sharp break in haplotype frequencies suggests strong selective pressures are operating on small spatial scales and illustrates that selection can create high divergence even in marine species with ample opportunities for gene flow.
Collapse
Affiliation(s)
- Ingrid Spies
- Resource Ecology and Fisheries Management DivisionAlaska Fisheries Science CenterSeattleWashingtonUSA
| | - Daniel P. Drinan
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Eleni L. Petrou
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Rory Spurr
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Carolyn Tarpey
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Theodore Hartinger
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Wes Larson
- Ted Stevens Marine Research InstituteAlaska Fisheries Science Center/Auke Bay LaboratoryJuneauAlaskaUSA
| | - Lorenz Hauser
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| |
Collapse
|
29
|
Chafin TK, Regmi B, Douglas MR, Edds DR, Wangchuk K, Dorji S, Norbu P, Norbu S, Changlu C, Khanal GP, Tshering S, Douglas ME. Parallel introgression, not recurrent emergence, explains apparent elevational ecotypes of polyploid Himalayan snowtrout. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210727. [PMID: 34729207 PMCID: PMC8548808 DOI: 10.1098/rsos.210727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
The recurrence of similar evolutionary patterns within different habitats often reflects parallel selective pressures acting upon either standing or independently occurring genetic variation to produce a convergence of phenotypes. This interpretation (i.e. parallel divergences within adjacent streams) has been hypothesized for drainage-specific morphological 'ecotypes' observed in polyploid snowtrout (Cyprinidae: Schizothorax). However, parallel patterns of differential introgression during secondary contact are a viable alternative hypothesis. Here, we used ddRADseq (N = 35 319 de novo and N = 10 884 transcriptome-aligned SNPs), as derived from Nepali/Bhutanese samples (N = 48 each), to test these competing hypotheses. We first employed genome-wide allelic depths to derive appropriate ploidy models, then a Bayesian approach to yield genotypes statistically consistent under the inferred expectations. Elevational 'ecotypes' were consistent in geometric morphometric space, but with phylogenetic relationships at the drainage level, sustaining a hypothesis of independent emergence. However, partitioned analyses of phylogeny and admixture identified subsets of loci under selection that retained genealogical concordance with morphology, suggesting instead that apparent patterns of morphological/phylogenetic discordance are driven by widespread genomic homogenization. Here, admixture occurring in secondary contact effectively 'masks' previous isolation. Our results underscore two salient factors: (i) morphological adaptations are retained despite hybridization and (ii) the degree of admixture varies across tributaries, presumably concomitant with underlying environmental or anthropogenic factors.
Collapse
Affiliation(s)
- Tyler K. Chafin
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder 80309, USA
| | - Binod Regmi
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
- National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, Bethesda, MD 20892, USA
| | - Marlis R. Douglas
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - David R. Edds
- Department of Biological Sciences, Emporia State University, Emporia, KS 66801, USA
| | - Karma Wangchuk
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Sonam Dorji
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Pema Norbu
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Sangay Norbu
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Changlu Changlu
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Gopal Prasad Khanal
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Singye Tshering
- National Research and Development Centre for Riverine and Lake Fisheries, Ministry of Agriculture and Forests, Royal Government of Bhutan, Haa, Bhutan
| | - Michael E. Douglas
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| |
Collapse
|
30
|
Silva-Brandão KL, Cirino M, Magaldi LDM, Gueratto PE, Mattos RG, Freitas AVL. Subspecies limits and hidden Wolbachia diversity in Actinote pellenea butterflies. SYST BIODIVERS 2021. [DOI: 10.1080/14772000.2021.1965669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Karina L. Silva-Brandão
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Av. Candido Rondom, 400, Campinas, 13083-875, São Paulo, Brazil
| | - Mariana Cirino
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Av. Candido Rondom, 400, Campinas, 13083-875, São Paulo, Brazil
| | - Luiza De Moraes Magaldi
- Programa de Pós-graduação em Ecologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
- Instituto de Biologia, Departamento de Biologia Animal, Universidade Estadual de Campinas, Rua Monteiro Lobato, 255, Campinas, 13083-862, São Paulo, Brazil
| | - Patrícia Eyng Gueratto
- Programa de Pós-graduação em Ecologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
- Instituto de Biologia, Departamento de Biologia Animal, Universidade Estadual de Campinas, Rua Monteiro Lobato, 255, Campinas, 13083-862, São Paulo, Brazil
| | - Ricardo Gabriel Mattos
- Programa de Pós-graduação em Ecologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - André V. L. Freitas
- Instituto de Biologia, Departamento de Biologia Animal, Universidade Estadual de Campinas, Rua Monteiro Lobato, 255, Campinas, 13083-862, São Paulo, Brazil
| |
Collapse
|
31
|
Behrens KA, Girasek QL, Sickler A, Hyde J, Buonaccorsi VP. Regions of genetic divergence in depth-separated Sebastes rockfish species pairs: Depth as a potential driver of speciation. Mol Ecol 2021; 30:4259-4275. [PMID: 34181798 DOI: 10.1111/mec.16046] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/17/2021] [Accepted: 06/24/2021] [Indexed: 12/20/2022]
Abstract
Depth separation is a proposed driver of speciation in marine fishes, with marine rockfish (genus Sebastes) providing a potentially informative study system. Sebastes rockfishes are commercially and ecologically important. This genus encompasses more than one hundred species and the ecological and morphological variance between these species provides opportunity for identifying speciation-driving adaptations, particularly along a depth gradient. A reduced-representation sequencing method (ddRADseq) was used to compare 95 individuals encompassing six Sebastes species. In this study, we sought to identify regions of divergence between species that were indicative of divergent adaptation and reproductive barriers leading to speciation. A pairwise comparison of S. chrysomelas (black-and-yellow rockfish) and S. carnatus (gopher rockfish) FST values revealed three major regions of elevated genomic divergence, two of which were also present in the S. miniatus (vermilion rockfish) and S. crocotulus (sunset rockfish) comparison. These corresponded with regions of both elevated DXY values and reduced nucleotide diversity in two cases, suggesting a speciation-with-gene-flow evolutionary model followed by post-speciation selective sweeps within each species. Limited whole-genome resequencing was also performed to identify mutations with predicted effects between S. chrysomelas and S. carnatus. Within these islands, we identified important SNPs in genes involved in immune function and vision. This supports their potential role in speciation, as these are adaptive vectors noted in other organisms. Additionally, changes to genes involved in pigment expression and mate recognition shed light on how S. chrysomelas and S. carnatus may have become reproductively isolated.
Collapse
Affiliation(s)
- Kristen A Behrens
- Department of Biology, Juniata College, Huntingdon, Pennsylvania, USA
| | - Quinn L Girasek
- Department of Biology, Juniata College, Huntingdon, Pennsylvania, USA
| | - Alex Sickler
- Center for Data Driven Discovery in Biomedicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - John Hyde
- Fisheries Resources Division, Southwest Fisheries Science Center, NOAA Fisheries, La Jolla, California, USA
| | | |
Collapse
|
32
|
Kess T, Dempson JB, Lehnert SJ, Layton KKS, Einfeldt A, Bentzen P, Salisbury SJ, Messmer AM, Duffy S, Ruzzante DE, Nugent CM, Ferguson MM, Leong JS, Koop BF, O'Connell MF, Bradbury IR. Genomic basis of deep-water adaptation in Arctic Charr (Salvelinus alpinus) morphs. Mol Ecol 2021; 30:4415-4432. [PMID: 34152667 DOI: 10.1111/mec.16033] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/28/2021] [Accepted: 06/03/2021] [Indexed: 12/30/2022]
Abstract
The post-glacial colonization of Gander Lake in Newfoundland, Canada, by Arctic Charr (Salvelinus alpinus) provides the opportunity to study the genomic basis of adaptation to extreme deep-water environments. Colonization of deep-water (>50 m) habitats often requires extensive adaptation to cope with novel environmental challenges from high hydrostatic pressure, low temperature, and low light, but the genomic mechanisms underlying evolution in these environments are rarely known. Here, we compare genomic divergence between a deep-water morph adapted to depths of up to 288 m and a larger, piscivorous pelagic morph occupying shallower depths. Using both a SNP array and resequencing of whole nuclear and mitochondrial genomes, we find clear genetic divergence (FST = 0.11-0.15) between deep and shallow water morphs, despite an absence of morph divergence across the mitochondrial genome. Outlier analyses identified many diverged genomic regions containing genes enriched for processes such as gene expression and DNA repair, cardiac function, and membrane transport. Detection of putative copy number variants (CNVs) uncovered 385 genes with CNVs distinct to piscivorous morphs, and 275 genes with CNVs distinct to deep-water morphs, enriched for processes associated with synapse assembly. Demographic analyses identified evidence for recent and local morph divergence, and ongoing reductions in diversity consistent with postglacial colonization. Together, these results show that Arctic Charr morph divergence has occurred through genome-wide differentiation and elevated divergence of genes underlying multiple cellular and physiological processes, providing insight into the genomic basis of adaptation in a deep-water habitat following postglacial recolonization.
Collapse
Affiliation(s)
- Tony Kess
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - J Brian Dempson
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Sarah J Lehnert
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Kara K S Layton
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Anthony Einfeldt
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Paul Bentzen
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | | | - Amber M Messmer
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Steven Duffy
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | | | - Cameron M Nugent
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Moira M Ferguson
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Jong S Leong
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Ben F Koop
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Michael F O'Connell
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Ian R Bradbury
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| |
Collapse
|
33
|
Hierarchical genetic structure in an evolving species complex: Insights from genome wide ddRAD data in Sebastes mentella. PLoS One 2021; 16:e0251976. [PMID: 34043665 PMCID: PMC8158871 DOI: 10.1371/journal.pone.0251976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 05/06/2021] [Indexed: 11/22/2022] Open
Abstract
The diverse biology and ecology of marine organisms may lead to complex patterns of intraspecific diversity for both neutral and adaptive genetic variation. Sebastes mentella displays a particular life-history as livebearers, for which existence of multiple ecotypes has been suspected to complicate the genetic population structure of the species. Double digest restriction-site associated DNA was used to investigate genetic population structure in S. mentella and to scan for evidence of selection. In total, 42,288 SNPs were detected in 277 fish, and 1,943 neutral and 97 tentatively adaptive loci were selected following stringent filtration. Unprecedented levels of genetic differentiation were found among the previously defined ‘shallow pelagic’, ‘deep pelagic’ and ‘demersal slope’ ecotypes, with overall mean FST = 0.05 and 0.24 in neutral and outlier SNPs, respectively. Bayesian computation estimated a concurrent and historical divergence among these three ecotypes and evidence of local adaptation was found in the S. mentella genome. Overall, these findings imply that the depth-defined habitat divergence of S. mentella has led to reproductive isolation and possibly adaptive radiation among these ecotypes. Additional sub-structuring was detected within the ‘shallow’ and ‘deep’ pelagic ecotypes. Population assignment of individual fish showed more than 94% agreement between results based on SNP and previously generated microsatellite data, but the SNP data provided a lower estimate of hybridization among the ecotypes than that by microsatellite data. We identified a SNP panel with only 21 loci to discriminate populations in mixed samples based on a machine-learning algorithm. This first SNP based investigation clarifies the population structure of S. mentella, and provides novel and high-resolution genomic tools for future investigations. The insights and tools provided here can readily be incorporated into the management of S. mentella and serve as a template for other exploited marine species exhibiting similar complex life history traits.
Collapse
|
34
|
Chueca LJ, Schell T, Pfenninger M. Whole-genome re-sequencing data to infer historical demography and speciation processes in land snails: the study of two Candidula sister species. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200156. [PMID: 33813898 PMCID: PMC8059500 DOI: 10.1098/rstb.2020.0156] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Despite the global biodiversity of terrestrial gastropods and their ecological and economic importance, the genomic basis of ecological adaptation and speciation in land snail taxa is still largely unknown. Here, we combined whole-genome re-sequencing with population genomics to evaluate the historical demography and the speciation process of two closely related species of land snails from western Europe, Candidula unifasciata and C. rugosiuscula. Historical demographic analysis indicated fluctuations in the size of ancestral populations, probably driven by Pleistocene climatic fluctuations. Although the current population distributions of both species do not overlap, our approximate Bayesian computation model selection approach on several speciation scenarios suggested that gene flow has occurred throughout the divergence process until recently. Positively selected genes diverging early in the process were associated with intragenomic and cyto-nuclear incompatibilities, respectively, potentially fostering reproductive isolation as well as ecological divergence. Our results suggested that the speciation between species entails complex processes involving both gene flow and ecological speciation, and that further research based on whole-genome data can provide valuable understanding on species divergence. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
Collapse
Affiliation(s)
- Luis J. Chueca
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberg Nature Research Society, 60325 Frankfurt am Main, Germany
- Department of Zoology and Animal Cell Biology, University of the Basque Country (UPV-EHU), 01006 Vitoria-Gasteiz, Spain
- Molecular Ecology, Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Tilman Schell
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberg Nature Research Society, 60325 Frankfurt am Main, Germany
| | - Markus Pfenninger
- LOEWE-Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberg Nature Research Society, 60325 Frankfurt am Main, Germany
- Molecular Ecology, Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt am Main, Germany
- Institute of Organismic and Molecular Evolution (iOME), Faculty of Biology, Johannes Gutenberg University, 55128 Mainz, Germany
| |
Collapse
|
35
|
Chase MA, Ellegren H, Mugal CF. Positive selection plays a major role in shaping signatures of differentiation across the genomic landscape of two independent Ficedula flycatcher species pairs. Evolution 2021; 75:2179-2196. [PMID: 33851440 DOI: 10.1111/evo.14234] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 03/05/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022]
Abstract
A current debate within population genomics surrounds the relevance of patterns of genomic differentiation between closely related species for our understanding of adaptation and speciation. Mounting evidence across many taxa suggests that the same genomic regions repeatedly develop elevated differentiation in independent species pairs. These regions often coincide with high gene density and/or low recombination, leading to the hypothesis that the genomic differentiation landscape mostly reflects a history of background selection, and reveals little about adaptation or speciation. A comparative genomics approach with multiple independent species pairs at a timescale where gene flow and ILS are negligible permits investigating whether different evolutionary processes are responsible for generating lineage-specific versus shared patterns of species differentiation. We use whole-genome resequencing data of 195 individuals from four Ficedula flycatcher species comprising two independent species pairs: collared and pied flycatchers, and red-breasted and taiga flycatchers. We found that both shared and lineage-specific FST peaks could partially be explained by selective sweeps, with recurrent selection likely to underlie shared signatures of selection, whereas indirect evidence supports a role of recombination landscape evolution in driving lineage-specific signatures of selection. This work therefore provides evidence for an interplay of positive selection and recombination to genomic landscape evolution.
Collapse
Affiliation(s)
- Madeline A Chase
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala university, Uppsala, SE-75236, Sweden
| | - Hans Ellegren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala university, Uppsala, SE-75236, Sweden
| | - Carina F Mugal
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala university, Uppsala, SE-75236, Sweden
| |
Collapse
|
36
|
Christmas MJ, Jones JC, Olsson A, Wallerman O, Bunikis I, Kierczak M, Peona V, Whitley KM, Larva T, Suh A, Miller-Struttmann NE, Geib JC, Webster MT. Genetic Barriers to Historical Gene Flow between Cryptic Species of Alpine Bumblebees Revealed by Comparative Population Genomics. Mol Biol Evol 2021; 38:3126-3143. [PMID: 33823537 PMCID: PMC8321533 DOI: 10.1093/molbev/msab086] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Evidence is accumulating that gene flow commonly occurs between recently diverged species, despite the existence of barriers to gene flow in their genomes. However, we still know little about what regions of the genome become barriers to gene flow and how such barriers form. Here, we compare genetic differentiation across the genomes of bumblebee species living in sympatry and allopatry to reveal the potential impact of gene flow during species divergence and uncover genetic barrier loci. We first compared the genomes of the alpine bumblebee Bombus sylvicola and a previously unidentified sister species living in sympatry in the Rocky Mountains, revealing prominent islands of elevated genetic divergence in the genome that colocalize with centromeres and regions of low recombination. This same pattern is observed between the genomes of another pair of closely related species living in allopatry (B. bifarius and B. vancouverensis). Strikingly however, the genomic islands exhibit significantly elevated absolute divergence (dXY) in the sympatric, but not the allopatric, comparison indicating that they contain loci that have acted as barriers to historical gene flow in sympatry. Our results suggest that intrinsic barriers to gene flow between species may often accumulate in regions of low recombination and near centromeres through processes such as genetic hitchhiking, and that divergence in these regions is accentuated in the presence of gene flow.
Collapse
Affiliation(s)
- Matthew J Christmas
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Julia C Jones
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,School of Biology and Environmental Science, University College Dublin, Dublin, Ireland
| | - Anna Olsson
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ola Wallerman
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ignas Bunikis
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Marcin Kierczak
- Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Valentina Peona
- Department of Organismal Biology-Systematic Biology, Uppsala University, Uppsala, Sweden
| | - Kaitlyn M Whitley
- Department of Biology, Appalachian State University, Boone, NC, USA.,U.S. Department of Agriculture, Agriculture Research Service, Charleston, SC, USA
| | - Tuuli Larva
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Alexander Suh
- Department of Organismal Biology-Systematic Biology, Uppsala University, Uppsala, Sweden.,School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | | | - Jennifer C Geib
- Department of Biology, Appalachian State University, Boone, NC, USA
| | - Matthew T Webster
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| |
Collapse
|
37
|
Schield DR, Scordato ESC, Smith CCR, Carter JK, Cherkaoui SI, Gombobaatar S, Hajib S, Hanane S, Hund AK, Koyama K, Liang W, Liu Y, Magri N, Rubtsov A, Sheta B, Turbek SP, Wilkins MR, Yu L, Safran RJ. Sex-linked genetic diversity and differentiation in a globally distributed avian species complex. Mol Ecol 2021; 30:2313-2332. [PMID: 33720472 DOI: 10.1111/mec.15885] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/19/2021] [Accepted: 03/10/2021] [Indexed: 12/15/2022]
Abstract
Sex chromosomes often bear distinct patterns of genetic variation due to unique patterns of inheritance and demography. The processes of mutation, recombination, genetic drift and selection also influence rates of evolution on sex chromosomes differently than autosomes. Measuring such differences provides information about how these processes shape genomic variation and their roles in the origin of species. To test hypotheses and predictions about patterns of autosomal and sex-linked genomic diversity and differentiation, we measured population genetic statistics within and between populations and subspecies of the barn swallow (Hirundo rustica) and performed explicit comparisons between autosomal and Z-linked genomic regions. We first tested for evidence of low Z-linked genetic diversity and high Z-linked population differentiation relative to autosomes, then for evidence that the Z chromosome bears greater ancestry information due to faster lineage sorting. Finally, we investigated geographical clines across hybrid zones for evidence that the Z chromosome is resistant to introgression due to selection against hybrids. We found evidence that the barn swallow mating system, demographic history and linked selection each contribute to low Z-linked diversity and high Z-linked differentiation. While incomplete lineage sorting is rampant across the genome, our results indicate faster sorting of ancestral polymorphism on the Z. Finally, hybrid zone analyses indicate barriers to introgression on the Z chromosome, suggesting that sex-linked traits are important in reproductive isolation, especially in migratory divide regions. Our study highlights how selection, gene flow and demography shape sex-linked genetic diversity and underlines the relevance of the Z chromosome in speciation.
Collapse
Affiliation(s)
- Drew R Schield
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Elizabeth S C Scordato
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.,Department of Biological Sciences, California State Polytechnic University, Pomona, CA, USA
| | - Chris C R Smith
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Javan K Carter
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Sidi Imad Cherkaoui
- Ecole Supérieure de Technologie de Khénifra, Sultan Moulay Slimane University, Béni-Mellal, Morocco
| | - Sundev Gombobaatar
- National University of Mongolia and Mongolian Ornithological Society, Ulaanbaatar, Mongolia
| | - Said Hajib
- Water and Forests Department, Forest Research Center, Rabat-Agdal, Morocco
| | - Saad Hanane
- Water and Forests Department, Forest Research Center, Rabat-Agdal, Morocco
| | - Amanda K Hund
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.,Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN, USA
| | | | - Wei Liang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou, China
| | - Yang Liu
- State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Guangzhou, China
| | - Najib Magri
- Water and Forests Department, Forest Research Center, Rabat-Agdal, Morocco
| | | | - Basma Sheta
- Zoology Department, Faculty of Science, Damietta University, New Damietta City, Egypt
| | - Sheela P Turbek
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Matthew R Wilkins
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.,Collaborative for STEM Education and Outreach, Vanderbilt University, Nashville, TN, USA
| | - Liu Yu
- Key Laboratory for Biodiversity Sciences and Ecological Engineering, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Rebecca J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| |
Collapse
|
38
|
Orsucci M, Sicard A. Flower evolution in the presence of heterospecific gene flow and its contribution to lineage divergence. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:971-989. [PMID: 33537708 DOI: 10.1093/jxb/eraa549] [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: 08/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The success of species depends on their ability to exploit ecological resources in order to optimize their reproduction. However, species are not usually found within single-species ecosystems but in complex communities. Because of their genetic relatedness, closely related lineages tend to cluster within the same ecosystem, rely on the same resources, and be phenotypically similar. In sympatry, they will therefore compete for the same resources and, in the case of flowering plants, exchange their genes through heterospecific pollen transfer. These interactions, nevertheless, pose significant challenges to species co-existence because they can lead to resource limitation and reproductive interference. In such cases, divergent selective pressures on floral traits will favour genotypes that isolate or desynchronize the reproduction of sympatric lineages. The resulting displacement of reproductive characters will, in turn, lead to pre-mating isolation and promote intraspecific divergence, thus initiating or reinforcing the speciation process. In this review, we discuss the current theoretical and empirical knowledge on the influence of heterospecific pollen transfer on flower evolution, highlighting its potential to uncover the ecological and genomic constraints shaping the speciation process.
Collapse
Affiliation(s)
- Marion Orsucci
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| |
Collapse
|
39
|
Schreiber D, Pfenninger M. Genomic divergence landscape in recurrently hybridizing Chironomus sister taxa suggests stable steady state between mutual gene flow and isolation. Evol Lett 2021; 5:86-100. [PMID: 33552538 PMCID: PMC7857304 DOI: 10.1002/evl3.204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/11/2020] [Accepted: 10/19/2020] [Indexed: 12/30/2022] Open
Abstract
Divergence is mostly viewed as a progressive process often initiated by selection targeting individual loci, ultimately resulting in ever increasing genomic isolation due to linkage. However, recent studies show that this process may stall at intermediate stable equilibrium states without achieving complete genomic isolation. We tested the extent of genomic isolation between two recurrently hybridizing nonbiting midge sister taxa, Chironomus riparius and Chironomus piger, by analyzing the divergence landscape. Using a principal component-based method, we estimated that only about 28.44% of the genomes were mutually isolated, whereas the rest was still exchanged. The divergence landscape was fragmented into isolated regions of on average 30 kb, distributed throughout the genome. Selection and divergence time strongly influenced lengths of isolated regions, whereas local recombination rate only had minor impact. Comparison of divergence time distributions obtained from several coalescence-simulated divergence scenarios with the observed divergence time estimates in an approximate Bayesian computation framework favored a short and concluded divergence event in the past. Most divergence happened during a short time span about 4.5 million generations ago, followed by a stable equilibrium between mutual gene flow through ongoing hybridization for the larger part of the genome and isolation in some regions due to rapid purifying selection of introgression, supported by high effective population sizes and recombination rates.
Collapse
Affiliation(s)
- Dennis Schreiber
- Department of Molecular EcologySenckenberg Biodiversity and Climate Research CentreFrankfurt am Main60325Germany
- Institute for Molecular and Organismic EvolutionJohannes Gutenberg UniversityMainz55128Germany
| | - Markus Pfenninger
- Department of Molecular EcologySenckenberg Biodiversity and Climate Research CentreFrankfurt am Main60325Germany
- Institute for Molecular and Organismic EvolutionJohannes Gutenberg UniversityMainz55128Germany
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE‐TBG)Frankfurt am Main60325Germany
| |
Collapse
|
40
|
Byers KJRP, Darragh K, Fernanda Garza S, Abondano Almeida D, Warren IA, Rastas PMA, Merrill RM, Schulz S, McMillan WO, Jiggins CD. Clustering of loci controlling species differences in male chemical bouquets of sympatric Heliconius butterflies. Ecol Evol 2021; 11:89-107. [PMID: 33437416 PMCID: PMC7790645 DOI: 10.1002/ece3.6947] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 12/23/2022] Open
Abstract
The degree to which loci promoting reproductive isolation cluster in the genome-that is, the genetic architecture of reproductive isolation-can influence the tempo and mode of speciation. Tight linkage between these loci can facilitate speciation in the face of gene flow. Pheromones play a role in reproductive isolation in many Lepidoptera species, and the role of endogenously produced compounds as secondary metabolites decreases the likelihood of pleiotropy associated with many barrier loci. Heliconius butterflies use male sex pheromones to both court females (aphrodisiac wing pheromones) and ward off male courtship (male-transferred antiaphrodisiac genital pheromones), and it is likely that these compounds play a role in reproductive isolation between Heliconius species. Using a set of backcross hybrids between H. melpomene and H. cydno, we investigated the genetic architecture of putative male pheromone compound production. We found a set of 40 significant quantitative trait loci (QTL) representing 33 potential pheromone compounds. QTL clustered significantly on two chromosomes, chromosome 8 for genital compounds and chromosome 20 for wing compounds, and chromosome 20 was enriched for potential pheromone biosynthesis genes. There was minimal overlap between pheromone QTL and known QTL for mate choice and color pattern. Nonetheless, we did detect linkage between a QTL for wing androconial area and optix, a color pattern locus known to play a role in reproductive isolation in these species. This tight clustering of putative pheromone loci might contribute to coincident reproductive isolating barriers, facilitating speciation despite ongoing gene flow.
Collapse
Affiliation(s)
- Kelsey J. R. P. Byers
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Smithsonian Tropical Research InstitutePanamaPanama
- Present address:
Department of Cell and Developmental BiologyJohn Innes CentreNorwichUK
| | - Kathy Darragh
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Smithsonian Tropical Research InstitutePanamaPanama
- Present address:
Department of Evolution and EcologyUniversity of California DavisDavisCAUSA
| | - Sylvia Fernanda Garza
- Smithsonian Tropical Research InstitutePanamaPanama
- Present address:
Department of Collective BehaviourMax Planck Institute of Animal BehaviourKonstanzGermany
| | - Diana Abondano Almeida
- Smithsonian Tropical Research InstitutePanamaPanama
- Present address:
Institute for Ecology, Evolution and DiversityGoethe UniversitätFrankfurtGermany
| | - Ian A. Warren
- Department of ZoologyUniversity of CambridgeCambridgeUK
| | | | - Richard M. Merrill
- Smithsonian Tropical Research InstitutePanamaPanama
- Division of Evolutionary BiologyLudwig‐Maximilians‐Universität MünchenMunichGermany
| | - Stefan Schulz
- Institute of Organic ChemistryDepartment of Life SciencesTechnische Universität BraunschweigBraunschweigGermany
| | | | - Chris D. Jiggins
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Smithsonian Tropical Research InstitutePanamaPanama
| |
Collapse
|
41
|
Genome evolution of blind subterranean mole rats: Adaptive peripatric versus sympatric speciation. Proc Natl Acad Sci U S A 2020; 117:32499-32508. [PMID: 33277437 DOI: 10.1073/pnas.2018123117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Speciation mechanisms remain controversial. Two speciation models occur in Israeli subterranean mole rats, genus Spalax: a regional speciation cline southward of four peripatric climatic chromosomal species and a local, geologic-edaphic, genic, and sympatric speciation. Here we highlight their genome evolution. The five species were separated into five genetic clusters by single nucleotide polymorphisms, copy number variations (CNVs), repeatome, and methylome in sympatry. The regional interspecific divergence correspond to Pleistocene climatic cycles. Climate warmings caused chromosomal speciation. Triple effective population size, N e , declines match glacial cold cycles. Adaptive genes evolved under positive selection to underground stresses and to divergent climates, involving interspecies reproductive isolation. Genomic islands evolved mainly due to adaptive evolution involving ancient polymorphisms. Repeatome, including both CNV and LINE1 repetitive elements, separated the five species. Methylation in sympatry identified geologically chalk-basalt species that differentially affect thermoregulation, hypoxia, DNA repair, P53, and other pathways. Genome adaptive evolution highlights climatic and geologic-edaphic stress evolution and the two speciation models, peripatric and sympatric.
Collapse
|
42
|
Wang S, Rohwer S, de Zwaan DR, Toews DPL, Lovette IJ, Mackenzie J, Irwin D. Selection on a small genomic region underpins differentiation in multiple color traits between two warbler species. Evol Lett 2020; 4:502-515. [PMID: 33312686 PMCID: PMC7719548 DOI: 10.1002/evl3.198] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 09/20/2020] [Accepted: 09/30/2020] [Indexed: 11/18/2022] Open
Abstract
Speciation is one of the most important processes in biology, yet the study of the genomic changes underlying this process is in its infancy. North American warbler species Setophaga townsendi and Setophaga occidentalis hybridize in a stable hybrid zone, following a period of geographic separation. Genomic differentiation accumulated during geographic isolation can be homogenized by introgression at secondary contact, whereas genetic regions that cause low hybrid fitness can be shielded from such introgression. Here, we examined the genomic underpinning of speciation by investigating (1) the genetic basis of divergent pigmentation traits between species, (2) variation in differentiation across the genome, and (3) the evidence for selection maintaining differentiation in the pigmentation genes. Using tens of thousands of single nucleotide polymorphisms (SNPs) genotyped in hundreds of individuals within and near the hybrid zone, genome-wide association mapping revealed a single SNP associated with cheek, crown, breast coloration, and flank streaking, reflecting pleiotropy (one gene affecting multiple traits) or close physical linkage of different genes affecting different traits. This SNP is within an intron of the RALY gene, hence we refer to it as the RALY SNP. We then examined between-species genomic differentiation, using both genotyping-by-sequencing and whole genome sequencing. We found that the RALY SNP is within one of the highest peaks of differentiation, which contains three genes known to influence pigmentation: ASIP, EIF2S2, and RALY (the ASIP-RALY gene block). Heterozygotes at this gene block are likely of reduced fitness, as the geographic cline of the RALY SNP has been narrow over two decades. Together, these results reflect at least one barrier to gene flow within this narrow (∼200 kb) genomic region that modulates plumage difference between species. Despite extensive gene flow between species across the genome, this study provides evidence that selection on a phenotype-associated genomic region maintains a stable species boundary.
Collapse
Affiliation(s)
- Silu Wang
- Department of Zoology and Biodiversity Research CentreUniversity of British ColumbiaVancouverBCV6T1Z4Canada
| | - Sievert Rohwer
- Department of Biology and Burke MuseumUniversity of WashingtonSeattleWashington98195
| | - Devin R. de Zwaan
- Department of Forest and Conservation SciencesUniversity of British ColumbiaVancouverBCV6T1Z4Canada
| | - David P. L. Toews
- Department of Biology619 Mueller LaboratoryPennsylvania State UniversityUniversity ParkPennsylvania16802
| | - Irby J. Lovette
- Fuller Evolutionary Biology ProgramCornell Lab of OrnithologyIthacaNew York14850
| | - Jacqueline Mackenzie
- Department of Zoology and Biodiversity Research CentreUniversity of British ColumbiaVancouverBCV6T1Z4Canada
| | - Darren Irwin
- Department of Zoology and Biodiversity Research CentreUniversity of British ColumbiaVancouverBCV6T1Z4Canada
| |
Collapse
|
43
|
Kess T, Brachmann M, Boulding EG. Putative chromosomal rearrangements are associated primarily with ecotype divergence rather than geographic separation in an intertidal, poorly dispersing snail. J Evol Biol 2020; 34:193-207. [PMID: 33108001 DOI: 10.1111/jeb.13724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 09/29/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022]
Abstract
Littorina saxatilis is becoming a model system for understanding the genomic basis of ecological speciation. The parallel formation of crab-adapted ecotypes that exhibit partial reproductive isolation from wave-adapted ecotypes has enabled genomic investigation of conspicuous shell traits. Recent genomic studies suggest that chromosomal rearrangements may enable ecotype divergence by reducing gene flow. However, the genomic architecture of traits that are divergent between ecotypes remains poorly understood. Here, we use 11,504 single nucleotide polymorphism (SNP) markers called using the recently released L. saxatilis genome to genotype 462 crab ecotype, wave ecotype and phenotypically intermediate Spanish L. saxatilis individuals with scored phenotypes. We used redundancy analysis to study the genetic architecture of loci associated with shell shape, shape corrected for size, shell size and shell ornamentation, and to compare levels of co-association among different traits. We discovered 341 SNPs associated with shell traits. Loci associated with trait divergence between ecotypes were often located inside putative chromosomal rearrangements recently characterized in Swedish L. saxatilis. In contrast, we found that shell shape corrected for size varied primarily by geographic site rather than by ecotype and showed little association with these putative rearrangements. We conclude that genomic regions of elevated divergence inside putative rearrangements were associated with divergence of L. saxatilis ecotypes along steep environmental axes-consistent with models of adaptation with gene flow-but were not associated with divergence among the three geographical sites. Our findings support predictions from models indicating the importance of genomic regions of reduced recombination allowing co-association of loci during ecological speciation with ongoing gene flow.
Collapse
Affiliation(s)
- Tony Kess
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Matthew Brachmann
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | | |
Collapse
|
44
|
Nam K, Nhim S, Robin S, Bretaudeau A, Nègre N, d'Alençon E. Positive selection alone is sufficient for whole genome differentiation at the early stage of speciation process in the fall armyworm. BMC Evol Biol 2020; 20:152. [PMID: 33187468 PMCID: PMC7663868 DOI: 10.1186/s12862-020-01715-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 10/28/2020] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The process of speciation involves differentiation of whole genome sequences between a pair of diverging taxa. In the absence of a geographic barrier and in the presence of gene flow, genomic differentiation may occur when the homogenizing effect of recombination is overcome across the whole genome. The fall armyworm is observed as two sympatric strains with different host-plant preferences across the entire habitat. These two strains exhibit a very low level of genetic differentiation across the whole genome, suggesting that genomic differentiation occurred at an early stage of speciation. In this study, we aim at identifying critical evolutionary forces responsible for genomic differentiation in the fall armyworm. RESULTS These two strains exhibit a low level of genomic differentiation (FST = 0.0174), while 99.2% of 200 kb windows have genetically differentiated sequences (FST > 0). We found that the combined effect of mild positive selection and genetic linkage to selectively targeted loci are responsible for the genomic differentiation. However, a single event of very strong positive selection appears not to be responsible for genomic differentiation. The contribution of chromosomal inversions or tight genetic linkage among positively selected loci causing reproductive barriers is not supported by our data. Phylogenetic analysis shows that the genomic differentiation occurred by sub-setting of genetic variants in one strain from the other. CONCLUSIONS From these results, we concluded that genomic differentiation may occur at the early stage of a speciation process in the fall armyworm and that mild positive selection targeting many loci alone is sufficient evolutionary force for generating the pattern of genomic differentiation. This genomic differentiation may provide a condition for accelerated genomic differentiation by synergistic effects among linkage disequilibrium generated by following events of positive selection. Our study highlights genomic differentiation as a key evolutionary factor connecting positive selection to divergent selection.
Collapse
Affiliation(s)
- Kiwoong Nam
- DGIMI, Univ Montpellier, INRAE, Montpellier, France.
| | - Sandra Nhim
- DGIMI, Univ Montpellier, INRAE, Montpellier, France
| | - Stéphanie Robin
- INRAE, UMR-IGEPP, BioInformatics Platform for Agroecosystems Arthropods, Campus Beaulieu, Rennes, France
- INRIA, IRISA, GenOuest Core Facility, Campus de Beaulieu, Rennes, France
| | - Anthony Bretaudeau
- INRAE, UMR-IGEPP, BioInformatics Platform for Agroecosystems Arthropods, Campus Beaulieu, Rennes, France
- INRIA, IRISA, GenOuest Core Facility, Campus de Beaulieu, Rennes, France
| | | | | |
Collapse
|
45
|
Choi JY, Purugganan M, Stacy EA. Divergent Selection and Primary Gene Flow Shape Incipient Speciation of a Riparian Tree on Hawaii Island. Mol Biol Evol 2020; 37:695-710. [PMID: 31693149 PMCID: PMC7038655 DOI: 10.1093/molbev/msz259] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A long-standing goal of evolutionary biology is to understand the mechanisms underlying the formation of species. Of particular interest is whether or not speciation can occur in the presence of gene flow and without a period of physical isolation. Here, we investigated this process within Hawaiian Metrosideros, a hypervariable and highly dispersible woody species complex that dominates the Hawaiian Islands in continuous stands. Specifically, we investigated the origin of Metrosideros polymorpha var. newellii (newellii), a riparian ecotype endemic to Hawaii Island that is purportedly derived from the archipelago-wide M. polymorpha var. glaberrima (glaberrima). Disruptive selection across a sharp forest-riparian ecotone contributes to the isolation of these varieties and is a likely driver of newellii's origin. We examined genome-wide variation of 42 trees from Hawaii Island and older islands. Results revealed a split between glaberrima and newellii within the past 0.3-1.2 My. Admixture was extensive between lineages within Hawaii Island and between islands, but introgression from populations on older islands (i.e., secondary gene flow) did not appear to contribute to the emergence of newellii. In contrast, recurrent gene flow (i.e., primary gene flow) between glaberrima and newellii contributed to the formation of genomic islands of elevated absolute and relative divergence. These regions were enriched for genes with regulatory functions as well as for signals of positive selection, especially in newellii, consistent with divergent selection underlying their formation. In sum, our results support riparian newellii as a rare case of incipient ecological speciation with primary gene flow in trees.
Collapse
Affiliation(s)
- Jae Young Choi
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY
| | - Michael Purugganan
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY.,Center for Genomics and Systems Biology, NYU Abu Dhabi Research Institute, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Elizabeth A Stacy
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV
| |
Collapse
|
46
|
The Genomic Landscape of Divergence Across the Speciation Continuum in Island-Colonising Silvereyes ( Zosterops lateralis). G3-GENES GENOMES GENETICS 2020; 10:3147-3163. [PMID: 32660974 PMCID: PMC7466963 DOI: 10.1534/g3.120.401352] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Inferring the evolutionary dynamics at play during the process of speciation by analyzing the genomic landscape of divergence is a major pursuit in population genomics. However, empirical assessments of genomic landscapes under varying evolutionary scenarios that are known a priori are few, thereby limiting our ability to achieve this goal. Here we combine RAD-sequencing and individual-based simulations to evaluate the genomic landscape of divergence in the silvereye (Zosterops lateralis). Using pairwise comparisons that differ in divergence timeframe and the presence or absence of gene flow, we document how genomic patterns accumulate along the speciation continuum. In contrast to previous predictions, our results provide limited support for the idea that divergence accumulates around loci under divergent selection or that genomic islands widen with time. While a small number of genomic islands were found in populations diverging with and without gene flow, in few cases were SNPs putatively under selection tightly associated with genomic islands. The transition from localized to genome-wide levels of divergence was captured using individual-based simulations that considered only neutral processes. Our results challenge the ubiquity of existing verbal models that explain the accumulation of genomic differences across the speciation continuum and instead support the idea that divergence both within and outside of genomic islands is important during the speciation process.
Collapse
|
47
|
Lehnert SJ, Kess T, Bentzen P, Clément M, Bradbury IR. Divergent and linked selection shape patterns of genomic differentiation between European and North American Atlantic salmon (Salmo salar). Mol Ecol 2020; 29:2160-2175. [PMID: 32432380 DOI: 10.1111/mec.15480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/17/2020] [Accepted: 05/11/2020] [Indexed: 02/06/2023]
Abstract
As populations diverge many processes can shape genomic patterns of differentiation. Regions of high differentiation can arise due to divergent selection acting on selected loci, genetic hitchhiking of nearby loci, or through repeated selection against deleterious alleles (linked background selection); this divergence may then be further elevated in regions of reduced recombination. Atlantic salmon (Salmo salar) from Europe and North America diverged >600,000 years ago and despite some evidence of secondary contact, the majority of genetic data indicate substantial divergence between lineages. This deep divergence with potential gene flow provides an opportunity to investigate the role of different mechanisms that shape the genomic landscape during early speciation. Here, using 184,295 single nucleotide polymorphisms (SNPs) and 80 populations, we investigate the genomic landscape of differentiation across the Atlantic Ocean with a focus on highly differentiated regions and the processes shaping them. We found evidence of high (mean FST = 0.26) and heterogeneous genomic differentiation between continents. Genomic regions associated with high trans-Atlantic differentiation ranged in size from single loci (SNPs) within important genes to large regions (1-3 Mbp) on four chromosomes (Ssa06, Ssa13, Ssa16 and Ssa19). These regions showed signatures consistent with selection, including high linkage disequilibrium, despite no significant reduction in recombination. Genes and functional enrichment of processes associated with differentiated regions may highlight continental differences in ocean navigation and parasite resistance. Our results provide insight into potential mechanisms underlying differences between continents, and evidence of near-fixed and potentially adaptive trans-Atlantic differences concurrent with a background of high genome-wide differentiation supports subspecies designation in Atlantic salmon.
Collapse
Affiliation(s)
- Sarah J Lehnert
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Tony Kess
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Paul Bentzen
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Marie Clément
- Centre for Fisheries Ecosystems Research, Fisheries and Marine Institute, Memorial University of Newfoundland, St. John's, NL, Canada.,Labrador Institute, Memorial University of Newfoundland, Happy Valley-Goose Bay, NL, Canada
| | - Ian R Bradbury
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada.,Department of Biology, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
48
|
Ackiss AS, Larson WA, Stott W. Genotyping-by-sequencing illuminates high levels of divergence among sympatric forms of coregonines in the Laurentian Great Lakes. Evol Appl 2020; 13:1037-1054. [PMID: 32431751 PMCID: PMC7232772 DOI: 10.1111/eva.12919] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 02/06/2023] Open
Abstract
Effective resource management depends on our ability to partition diversity into biologically meaningful units. Recent evolutionary divergence, however, can often lead to ambiguity in morphological and genetic differentiation, complicating the delineation of valid conservation units. Such is the case with the "coregonine problem," where recent postglacial radiations of coregonines into lacustrine habitats resulted in the evolution of numerous species flocks, often with ambiguous taxonomy. The application of genomics methods is beginning to shed light on this problem and the evolutionary mechanisms underlying divergence in these ecologically and economically important fishes. Here, we used restriction site-associated DNA (RAD) sequencing to examine genetic diversity and differentiation among sympatric forms in the Coregonus artedi complex in the Apostle Islands of Lake Superior, the largest lake in the Laurentian Great Lakes. Using 29,068 SNPs, we were able to clearly distinguish among the three most common forms for the first time, as well as identify putative hybrids and potentially misidentified specimens. Population assignment rates for these forms using our RAD data were 93%-100% with the only mis-assignments arising from putative hybrids, an improvement from 62% to 77% using microsatellites. Estimates of pairwise differentiation (F ST: 0.045-0.056) were large given the detection of hybrids, suggesting that reduced fitness of hybrid individuals may be a potential mechanism for the maintenance of differentiation. We also used a newly built C. artedi linkage map to look for islands of genetic divergence among forms and found widespread differentiation across the genome, a pattern indicative of long-term drift, suggesting that these forms have been reproductively isolated for a substantial amount of time. The results of this study provide valuable information that can be applied to develop well-informed management strategies and stress the importance of re-evaluating conservation units with genomic tools to ensure they accurately reflect species diversity.
Collapse
Affiliation(s)
- Amanda S. Ackiss
- Wisconsin Cooperative Fishery Research UnitCollege of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsin
| | - Wesley A. Larson
- U.S. Geological SurveyWisconsin Cooperative Fishery Research UnitCollege of Natural ResourcesUniversity of Wisconsin‐Stevens PointStevens PointWisconsin
| | - Wendylee Stott
- U.S. Geological SurveyGreat Lakes Science CenterAnn ArborMichigan
| |
Collapse
|
49
|
Feng C, Yi H, Yang L, Kang M. The genetic basis of hybrid male sterility in sympatric Primulina species. BMC Evol Biol 2020; 20:49. [PMID: 32349663 PMCID: PMC7191819 DOI: 10.1186/s12862-020-01617-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 04/21/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Sympatric sister species provide an opportunity to investigate the genetic mechanisms and evolutionary forces that maintain species boundaries. The persistence of morphologically and genetically distinct populations in sympatry can only occur if some degree of reproductive isolation exists. A pair of sympatric sister species of Primulina (P. depressa and P. danxiaensis) was used to explore the genetic architecture of hybrid male sterility. RESULTS We mapped one major- and seven minor-effect quantitative trait loci (QTLs) that underlie pollen fertility rate (PFR). These loci jointly explained 55.4% of the phenotypic variation in the F2 population. A Bateson-Dobzhansky-Muller (BDM) model involving three loci was observed in this system. We found genotypic correlations between hybrid male sterility and flower morphology, consistent with the weak but significant phenotypic correlations between PFR and floral traits. CONCLUSIONS Hybrid male sterility in Primulina is controlled by a polygenic genetic basis with a complex pattern. The genetic incompatibility involves a three-locus BDM model. Hybrid male sterility is genetically correlated with floral morphology and divergence hitchhiking may occur between them.
Collapse
Affiliation(s)
- Chen Feng
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Huiqin Yi
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Lihua Yang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Ming Kang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, 510650 China
| |
Collapse
|
50
|
Huang K, Andrew RL, Owens GL, Ostevik KL, Rieseberg LH. Multiple chromosomal inversions contribute to adaptive divergence of a dune sunflower ecotype. Mol Ecol 2020; 29:2535-2549. [PMID: 32246540 DOI: 10.1111/mec.15428] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/19/2020] [Indexed: 12/19/2022]
Abstract
Both models and case studies suggest that chromosomal inversions can facilitate adaptation and speciation in the presence of gene flow by suppressing recombination between locally adapted alleles. Until recently, however, it has been laborious and time-consuming to identify and genotype inversions in natural populations. Here we apply RAD sequencing data and newly developed population genomic approaches to identify putative inversions that differentiate a sand dune ecotype of the prairie sunflower (Helianthus petiolaris) from populations found on the adjacent sand sheet. We detected seven large genomic regions that exhibit a different population structure than the rest of the genome and that vary in frequency between dune and nondune populations. These regions also show high linkage disequilibrium and high heterozygosity between, but not within, arrangements, consistent with the behaviour of large inversions, an inference subsequently validated in part by comparative genetic mapping. Genome-environment association analyses show that key environmental variables, including vegetation cover and soil nitrogen, are significantly associated with inversions. The inversions colocate with previously described "islands of differentiation," and appear to play an important role in adaptive divergence and incipient speciation within H. petiolaris.
Collapse
Affiliation(s)
- Kaichi Huang
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Rose L Andrew
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.,School of Environmental and Rural Science, University of New England, Armidale, NSW, Australia
| | - Gregory L Owens
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.,Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Kate L Ostevik
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.,Department of Biology, Duke University, Durham, NC, USA
| | - Loren H Rieseberg
- Department of Botany and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|