Autosomal suppression of meiotic drive can prevent sex chromosome cycling

Abstract

AbstractSex-ratio meiotic drivers are selfish genes or gene complexes that bias the transmission of chromosomes resulting in skewed sex ratios. While existing theoretical models have suggested the maintenance of a four-chromosome equilibrium (X, XSR, Y, YSUP; SR: sex-ratio driver, SUP: suppressor) in a cyclic dynamic, studies of natural populations have failed to capture this pattern. Although there are several plausible explanations for this lack of cycling, interference from autosomal suppressors has not been studied using a population genetic framework even though autosomal suppressors and Y-linked suppressors both exist in populations of some species. In this study, we use a simulations-based approach to investigate the influence of autosomal suppressors on the cycling of sex chromosomes. Our findings demonstrate that the presence of an autosomal suppressor can hinder the invasion of a Y-linked suppressor under some parameter space, thereby impeding the cyclic dynamics. Even when a Y-linked suppressor invades, the presence of an autosomal suppressor can prevent cycling. Our study demonstrates the potential role of autosomal suppressors in preventing sex chromosome cycling and provides insights into the conditions and consequences of the maintenance of both Y-linked and autosomal suppressors.