Selfish genes and sexual selection: the impact of genomic parasites on host reproduction

Abstract

Selfish genetic elements (SGEs) such as replicating mobile elements, segregation distorters, and maternally inherited endosymbionts, bias their transmission success relative to the rest of the genome to increase in representation in subsequent generations. As such they generate conflict with the rest of the genome. Such intra-genomic conflict is also a hallmark of sexually antagonistic (SA) alleles, which are shared genes between the sexes but that have opposing fitness effects when expressed in males and females. However, while both SGEs and SA alleles are recognised as common and potent sources of genomic conflict, the realisation that SGEs can also generate sexually antagonistic selection and contribute to sexual conflict in addition to generate sexual selection is largely overlooked. Here I show that SGEs frequently generate sex-specific selection and outline how SGEs that are associated with compromised male fertility can shape female mating patterns, play a key role in the dynamics of sex determination systems, and likely be an important source of sexually antagonistic genetic variation. Given the prevalence of SGEs their contribution to sexual conflict is likely to be greatly overlooked.