Sex-biased gene expression, sexual antagonism and levels of genetic diversity in the collared flycatcher (Ficedula albicollis) genome

Theoretical work suggests that sexual conflict should promote the maintenance of genetic diversity by the opposing directions of selection on males and females. If such
conflict is pervasive, it could potentially lead to genomic heterogeneity in levels of
genetic diversity an idea that so far has not been empirically tested on a genome-wide
scale. We used large-scale population genomic and transcriptomic data from the
collared flycatcher (Ficedula albicollis) to analyse how sexual conflict, for which we
use sex-biased gene expression as a proxy, relates to genetic variability. Here, we
demonstrate that the extent of sex-biased gene expression of both male-biased and
female-biased genes is significantly correlated with levels of nucleotide diversity in
gene sequences and that this correlation extends to diversity levels also in intergenic
DNA and introns. We find signatures of balancing selection in sex-biased genes but
also note that relaxed purifying selection could potential...