Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod.
Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD) and the presence of hyb...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4178228?pdf=render |
| _version_ | 1811205875738607616 |
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| author | Ian R Bradbury Sharen Bowman Tudor Borza Paul V R Snelgrove Jeffrey A Hutchings Paul R Berg Naiara Rodríguez-Ezpeleta Jackie Lighten Daniel E Ruzzante Christopher Taggart Paul Bentzen |
| author_facet | Ian R Bradbury Sharen Bowman Tudor Borza Paul V R Snelgrove Jeffrey A Hutchings Paul R Berg Naiara Rodríguez-Ezpeleta Jackie Lighten Daniel E Ruzzante Christopher Taggart Paul Bentzen |
| author_sort | Ian R Bradbury |
| collection | DOAJ |
| description | Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD) and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70%) occurring in or associated with (<5 kb) coding regions representing a diverse array of possible functions and pathways. Despite the observation that clinal loci were distributed across three linkage groups, elevated ILD was observed among all groups of clinal loci and strongest in comparisons involving a region of low recombination along linkage group 7. Evidence of ILD supports a hypothesis of divergence hitchhiking transitioning to genome hitchhiking consistent with reproductive isolation. This hypothesis is supported by Bayesian characterization of hybrid classes present and we find evidence of common F1 hybrids in several regions consistent with frequent interbreeding, yet little evidence of F2 or backcrossed individuals. This work suggests that significant barriers to hybridization and introgression exist among these co-occurring groups of cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species. |
| first_indexed | 2024-04-12T03:38:46Z |
| format | Article |
| id | doaj.art-424a87d0061e46f7883e4539ba66fcf0 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-12T03:38:46Z |
| publishDate | 2014-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-424a87d0061e46f7883e4539ba66fcf02022-12-22T03:49:21ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0199e10638010.1371/journal.pone.0106380Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod.Ian R BradburySharen BowmanTudor BorzaPaul V R SnelgroveJeffrey A HutchingsPaul R BergNaiara Rodríguez-EzpeletaJackie LightenDaniel E RuzzanteChristopher TaggartPaul BentzenHybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD) and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70%) occurring in or associated with (<5 kb) coding regions representing a diverse array of possible functions and pathways. Despite the observation that clinal loci were distributed across three linkage groups, elevated ILD was observed among all groups of clinal loci and strongest in comparisons involving a region of low recombination along linkage group 7. Evidence of ILD supports a hypothesis of divergence hitchhiking transitioning to genome hitchhiking consistent with reproductive isolation. This hypothesis is supported by Bayesian characterization of hybrid classes present and we find evidence of common F1 hybrids in several regions consistent with frequent interbreeding, yet little evidence of F2 or backcrossed individuals. This work suggests that significant barriers to hybridization and introgression exist among these co-occurring groups of cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species.http://europepmc.org/articles/PMC4178228?pdf=render |
| spellingShingle | Ian R Bradbury Sharen Bowman Tudor Borza Paul V R Snelgrove Jeffrey A Hutchings Paul R Berg Naiara Rodríguez-Ezpeleta Jackie Lighten Daniel E Ruzzante Christopher Taggart Paul Bentzen Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. PLoS ONE |
| title | Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. |
| title_full | Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. |
| title_fullStr | Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. |
| title_full_unstemmed | Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. |
| title_short | Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod. |
| title_sort | long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod |
| url | http://europepmc.org/articles/PMC4178228?pdf=render |
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