School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.
Evolution. 2018 Jun;72(6):1306-1316. doi: 10.1111/evo.13493. Epub 2018 May 5.
Antagonistic pleiotropy (AP)-where alleles of a gene increase some components of fitness at a cost to others-can generate balancing selection, and contribute to the maintenance of genetic variation in fitness traits, such as survival, fecundity, fertility, and mate competition. Previous theory suggests that AP is unlikely to maintain variation unless antagonistic selection is strong, or AP alleles exhibit pronounced differences in genetic dominance between the affected traits. We show that conditions for balancing selection under AP expand under the likely scenario that the strength of selection on each fitness component differs between the sexes. Our model also predicts that the vast majority of balanced polymorphisms have sexually antagonistic effects on total fitness, despite the absence of sexual antagonism for individual fitness components. We conclude that AP polymorphisms are less difficult to maintain than predicted by prior theory, even under our conservative assumption that selection on components of fitness is universally sexually concordant. We discuss implications for the maintenance of genetic variation, and for inferences of sexual antagonism that are based on sex-specific phenotypic selection estimates-many of which are based on single fitness components.
拮抗多效性（AP）——基因的等位基因以牺牲其他成分为代价增加某些适应性成分——可以产生平衡选择，并有助于维持生存、繁殖力、生育力和配偶竞争等适应性特征的遗传变异。先前的理论表明，除非拮抗选择很强，或者 AP 等位基因在受影响的性状之间表现出明显不同的遗传优势，否则 AP 不太可能维持变异。我们表明，在每种适应性成分的选择强度在两性之间存在差异的情况下，AP 下的平衡选择条件会扩大。我们的模型还预测，尽管个体适应性成分不存在性拮抗，但绝大多数平衡多态性对总适应性具有性拮抗作用。我们得出的结论是，AP 多态性比以前的理论预测更难维持，即使我们保守地假设适应性成分的选择在两性中普遍一致。我们讨论了对遗传变异维持的影响，以及基于特定性别表型选择估计的性拮抗推断的影响——其中许多基于单个适应性成分。
