PgmNr Z585: Introgression in Zebrafish and related species was mediated by genome structure.

Authors:
Braedan M. McCluskey; Peter Batzel; Jason Sydes; John H. Postlethwait


Institutes
University of Oregon, Eugene, OR.


Abstract:

Introgression is increasingly appreciated as a major contributor to species diversification. Using exome sequencing for zebrafish and ten related species, we show that introgression played a major role in the formation of several Danio species, including the zebrafish, Danio rerio. We find introgressed loci primarily in genomic regions with high recombination rate, which is strongly impacted by chromosome structure in zebrafish. Due to varying levels of introgression across the genome and a likely major chromosomal rearrangement, the closest historical relative of zebrafish varies for different genomic regions. These varied relationships across the genome give general insight into the effects of genome structure on introgression and the importance of incorporating structural genomic information into phylogenomic studies involving taxa with high levels of introgression. These results also provide specific insight into the complex speciation process in the recent history of a major model organism. Future studies investigating the phenotypic differences between zebrafish and other danios will need to account for this complex speciation process.