Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, 6009, Australia.
Nat Commun. 2019 Mar 25;10(1):1359. doi: 10.1038/s41467-019-09371-y.
The genic capture hypothesis, where sexually selected traits capture genetic variation in condition and the condition reflects genome-wide mutation load, stands to explain the presence of abundant genetic variation underlying sexually selected traits. Here we test this hypothesis by applying bidirectional selection to male mating success for 14 generations in replicate populations of Drosophila melanogaster. We then resequenced the genomes of flies from each population. Consistent with the central predictions of the genic capture hypothesis, we show that genetic variance decreased with success selection and increased with failure selection, providing evidence for purifying sexual selection. This pattern was distributed across the genome and no consistent molecular pathways were associated with divergence, consistent with condition being the target of selection. Together, our results provide molecular evidence suggesting that strong sexual selection erodes genetic variation, and that genome-wide mutation-selection balance contributes to its maintenance.
基因捕获假说认为，有性选择特征会捕获与健康状况相关的遗传变异，而健康状况反映了全基因组的突变负荷，该假说可以解释大量与有性选择特征相关的遗传变异的存在。在这里，我们通过在黑腹果蝇的重复种群中对雄性交配成功率进行双向选择来检验这一假说。然后，我们对每个种群的果蝇进行了基因组重测序。与基因捕获假说的核心预测一致，我们发现遗传方差随着成功选择而降低，随着失败选择而增加，这为净化性选择提供了证据。这种模式分布在整个基因组中，没有一致的分子途径与分歧相关，这与健康状况是选择的目标一致。总之，我们的研究结果提供了分子证据，表明强烈的性选择会侵蚀遗传变异，而全基因组的突变-选择平衡有助于维持遗传变异。
