Am Nat. 2021 May;197(5):543-559. doi: 10.1086/713739. Epub 2021 Apr 7.
AbstractIntralocus sexual conflict, or sexual antagonism, occurs when alleles have opposing fitness effects in the two sexes. Previous theory suggests that sexual antagonism is a driver of genetic variation by generating balancing selection. However, most of these studies assume that populations are well mixed, neglecting the effects of spatial subdivision. Here, we use mathematical modeling to show that limited dispersal changes evolution at sexually antagonistic autosomal and X-linked loci as a result of inbreeding and sex-specific kin competition. We find that if the sexes disperse at different rates, kin competition within the philopatric sex biases intralocus conflict in favor of the more dispersive sex. Furthermore, kin competition diminishes the strength of balancing selection relative to genetic drift, reducing genetic variation in small subdivided populations. Meanwhile, by decreasing heterozygosity, inbreeding reduces the scope for sexually antagonistic polymorphism due to nonadditive allelic effects, and this occurs to a greater extent on the X chromosome than autosomes. Overall, our results indicate that spatial structure is a relevant factor in predicting where sexually antagonistic alleles might be observed. We suggest that sex-specific dispersal ecology and demography can contribute to interspecific and intragenomic variation in sexual antagonism.
摘要：基因座内的性冲突，或性拮抗，是指等位基因在两性中具有相反的适合度效应时发生的情况。之前的理论认为，性拮抗是通过产生平衡选择来驱动遗传变异的。然而，这些研究大多假设群体是充分混合的，忽略了空间细分的影响。在这里，我们使用数学模型表明，由于近亲繁殖和性别特定的亲缘竞争，有限的扩散会改变性拮抗常染色体和 X 连锁基因座的进化。我们发现，如果两性以不同的速度扩散，亲代性别内的亲缘竞争会使基因座内的冲突偏向于更具扩散性的性别。此外，亲缘竞争相对于遗传漂变减弱了平衡选择的强度，减少了小分隔种群中的遗传变异。同时，由于非加性等位基因效应，近亲繁殖降低了性拮抗多态性的范围，这种情况在 X 染色体上比常染色体上更为严重。总的来说，我们的结果表明，空间结构是预测性拮抗等位基因可能出现的相关因素。我们认为，性别特异性的扩散生态和种群动态可以导致性拮抗的种间和基因组内变异。
