RT Journal Article
SR Electronic
T1 Whole genome sequences of Malawi cichlids reveal multiple radiations interconnected by gene flow
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 143859
DO 10.1101/143859
A1 Milan Malinsky
A1 Hannes Svardal
A1 Alexandra M. Tyers
A1 Eric A. Miska
A1 Martin J. Genner
A1 George F. Turner
A1 Richard Durbin
YR 2017
UL http://biorxiv.org/content/early/2017/12/04/143859.abstract
AB The hundreds of cichlid fish species in Lake Malawi constitute the most extensive recent vertebrate adaptive radiation. Here we characterize its genomic diversity by sequencing 134 individuals covering 73 species across all major lineages. Average sequence divergence between species pairs is only 0.1-0.25%. These divergence values overlap diversity within species, with 82% of heterozygosity shared between species. Phylogenetic analyses suggest that diversification initially proceeded by serial branching from a generalist Astatotilapia-like ancestor. However, no single species tree adequately represents all species relationships, with evidence for substantial gene flow at multiple times. Common signatures of selection on visual and oxygen transport genes shared by distantly related deep water species point to both adaptive introgression and independent selection. These findings enhance our understanding of genomic processes underlying rapid species diversification, and provide a platform for future genetic analysis of the Malawi radiation.One Sentence Summary The genomes of 73 cichlid fish species from Lake Malawi uncover evolutionary processes underlying a large adaptive evolutionary radiation. evolutionary processes underlying a large adaptive evolutionary radiation