Signals of positive selection in Palearctic bat species coexisting with a fungal pathogen

Abstract

AbstractTraits that directly influence the survival of an organism are suspect to positive selection. Disease can act as a driving force in shaping the genetic makeup across populations, even species, if the impacts are influencing a particularly sensitive part of their life cycles. White-nose syndrome is a fungal disease that affects bats during hibernation. The mycosis has caused massive population declines of susceptible species in North America, whereas in Eurasia, where the fungal pathogen has coevolved with its hosts for an extended period of time, bats appear to tolerate infection. Here, we adopted both whole-genome sequencing approaches and a literature search to compile a set of 300 genes from which to investigate for signals of positive selection in genomes of 11 Eurasian bats at the codon-level. Our results indicate significant positive selection in 38 genes, many of which have a marked role in responses to infection. Our findings suggest the fungal disease known as white-nose syndrome may have applied a significant selective pressure on hibernatory Eurasian Myotis-bats in the past, which can partially explain their survival in the presence of the pathogen.