title: High-resolution mapping reveals hundreds of genetic incompatibilities in hybridizing fish species.
abstract: Hybridization is increasingly being recognized as a common process in both animal and plant species. Negative epistatic interactions between genes from different parental genomes decrease the fitness of hybrids and can limit gene flow between species. However, little is known about the number and genome-wide distribution of genetic incompatibilities separating species. To detect interacting genes, we perform a high-resolution genome scan for linkage disequilibrium between unlinked genomic regions in naturally occurring hybrid populations of swordtail fish. We estimate that hundreds of pairs of genomic regions contribute to reproductive isolation between these species, despite them being recently diverged. Many of these incompatibilities are likely the result of natural or sexual selection on hybrids, since intrinsic isolation is known to be weak. Patterns of genomic divergence at these regions imply that genetic incompatibilities play a significant role in limiting gene flow even in young species.
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, United States.
authors.forename: Molly
authors.initials: M
authors.lastname: Schumer
authors.affiliation: Department of Biology, Texas A&M University, College Station, United States.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Cui
authors.affiliation: Department of Biology, Texas A&M University, College Station, United States.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Powell
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, United States.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dresner
authors.affiliation: Department of Biology, Texas A&M University, College Station, United States.
authors.forename: Gil G
authors.initials: GG
authors.lastname: Rosenthal
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, Princeton, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Andolfatto
mesh_terms: D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D003198:Computer Simulation; D004843:Epistasis, Genetic; D005260:Female; D005399:Fishes / Q000235:genetics*; D051456:Gene Flow; D015723:Gene Library; D016678:Genome; D005838:Genotype; D006824:Hybridization, Genetic; D015810:Linkage Disequilibrium; D008297:Male; D008957:Models, Genetic; D014960:X Chromosome
keywords: evolutionary biology; genetic incompatibilities; genomics; hybrid fitness; hybridization; speciation