The chicken Z chromosome is enriched for genes with preferential expression in ovarian somatic cells
Abstract
To elucidate the role of sexually antagonistic selection in the evolution of Z chromosome gene content in chicken, we analyzed publicly available microarray data from several somatic tissues as well as somatic and germ cells of the ovary. We found that the Z chromosome is enriched for genes showing preferential expression in ovarian somatic cells, but not for genes with preferential expression in primary oocytes or non-sex-specific somatic tissues.
Our results suggest that sexual antagonism leads to a higher abundance of female-benefit alleles on the Z chromosome. No bias towards Z-linkage for oocyte-enriched genes can be explained meiotic Z chromosome inactivation.
Our results are consistent with findings in mammals and indicate that recessive rather than dominant sexually antagonistic mutations shape the gene content of the X and Z chromosomes.