The genome of the Xingu Scale-backed Antbird (Willisornis vidua nigrigula) reveals lineage-specific adaptations

Antbirds (Thamnophilidae) are a large neotropical family of passerine bird
renowned for the ant-following foraging strategies of several members of
this clade. The high diversity of antbirds provides ample opportunity for
speciation studies, however these studies can be hindered by the lack of
an annotated antbird reference genome. In this study, we produced a
high-quality annotated reference genome for the
Xingu Scale-backed Antbird (Willisornis vidua nigrigula) using
10X Genomics Chromium linked-reads technology. The assembly is
1.09 Gb, with a scaffold N50 of 12.1 Mb and 17,475 annotated
protein coding genes. We compare the proteome of W. v.
nigrigula to several other passerines, and produce annotations
for two additional antbird genomes in order to identify genes under
lineage-specific positive selection and gene families with evidence for
significant expansions in antbirds. Several of these genes have functions
potentially related to the lineage-specific traits of antbirds, including
adaptations for thermoregulation in a humid tropical environment.