Data from: Convergence in hearing genes between echolocating birds and mammals

Echolocation, the detection of objects by means of sound waves, has
evolved independently in diverse animal lineages. Echolocating lineages
include not only mammals such as toothed whales, yangochiropteran and
rhinolophoid bats, but also Rousettus fruit bats, as well as two
bird lineages, the oilbirds and swiftlets, which use echolocation to
navigate in caves where they roost. In whales, yangochiropteran and
rhinolophoid bats, positive selection and molecular convergence has been
documented in key hearing-related genes, such as prestin (SLC26A5), but
few studies have examined these loci in other echolocators. Here, we
examine patterns of selection and convergence in echolocation-related
genes in echolocating birds and Rousettus bats. Fewer of these loci were
under selection in Rousettus or birds compared with classically-recognized
echolocators, and elevated convergence (compared to background lineages)
was not evident across this gene set. In certain genes, however, we
detected convergent substitutions with potential functional relevance,
including convergence between Rousettus and classic echolocators in
prestin at a site known to affect hair cell electromotility. We also
detected convergence between Yangochiroptera, Rhinolophidea and oilbirds
in TMC1, an important mechanosensory transduction channel in vertebrate
hair cells, and observed an amino acid change at the same site within the
pore domain. Our results suggest that although most proteins implicated in
echolocation in specialized mammals may not have been recruited in birds
or Rousettus fruit bats, certain hearing-related loci may have undergone
convergent functional changes. Investigating adaptations in diverse
echolocators such as swiftlets and oilbirds will deepen our understanding
of this unusual sensory modality.