Whole genome sequences of Malawi cichlids reveal multiple radiations interconnected by gene flow

Publication Type:Journal Article
Year of Publication:2017
Authors:Malinsky, M, Svardal, H, Tyers, AM, Miska, EA, Genner, MJ, Turner, GF, Durbin, R
Type of Article:Preprint posted 31 May 2017; open access (pdf at http://biorxiv.org/content/early/2017/05/31/143859.full.pdf)

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.

Basin / bassin: 

Who's online

There are currently 0 users online.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith