Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, United States.
Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States.
J Hered. 2024 Oct 23;115(6):660-671. doi: 10.1093/jhered/esae048.
Sex-ratio meiotic drivers are selfish genes or gene complexes that bias the transmission of sex chromosomes resulting in skewed sex ratios. Existing theoretical models have suggested the maintenance of a four-chromosome equilibrium (with driving and standard X and suppressing and susceptible Y) in a cyclic dynamic, but 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 theoretical population genetic framework even though autosomal suppressors and Y-linked suppressors coexist in natural populations of some species. In this study, we use a simulation-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, or even the invasion of Y-linked suppression. 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 maintaining both Y-linked and autosomal suppressors.
性比减数分裂驱动因子是自私基因或基因复合物，它们会偏向性染色体的传递，导致性比偏斜。现有的理论模型表明，在循环动态中维持四染色体平衡（具有驱动和标准 X 染色体以及抑制和易感 Y 染色体），但对自然种群的研究未能捕捉到这种模式。尽管对于这种缺乏循环存在几种合理的解释，但即使在一些物种的自然种群中存在常染色体抑制子和 Y 连锁抑制子，也没有使用理论种群遗传学框架来研究常染色体抑制子的干扰。在这项研究中，我们使用基于模拟的方法来研究常染色体抑制子对性染色体循环的影响。我们的研究结果表明，在某些参数空间下，常染色体抑制子的存在会阻碍 Y 连锁抑制子的入侵，从而阻碍循环动态，甚至阻碍 Y 连锁抑制的入侵。即使 Y 连锁抑制子入侵，常染色体抑制子的存在也可以防止循环。我们的研究表明常染色体抑制子在防止性染色体循环中的潜在作用，并为维持 Y 连锁和常染色体抑制子的条件和后果提供了见解。
