Genomic Evidence that Sexual Selection Impedes Adaptation to a Novel Environment
Genomic Evidence that Sexual Selection Impedes Adaptation to a Novel Environment
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DOI：
10.1016/j.cub.2015.05.034
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发表时间：
2015-07-20
期刊：
影响因子：
9.2
通讯作者：
Rundle, Howard D.
中科院分区：
文献类型：
--
作者：
Chenoweth, Stephen F.;Appleton, Nicholas C.;Rundle, Howard D.
人们普遍认为性选择能够产生显著的表型多样性[1,2]，但其对适应和清除有害突变的贡献尚未得到解决[10]。为了深入了解性选择对整个基因组自然分离多态性的影响，我们之前在一个新的环境中进化了12个有锯齿的果蝇种群，利用自然选择和性选择的机会因子操纵bbb。在这里，我们对进化人群中的1400多个snp进行了基因型分析，并揭示了性选择影响了许多与自然选择相同的基因组区域，与自然选择一致的频率与自然选择相反的频率一样高。有趣的是，80个snp中有一半以上显示了自然选择和性选择之间的相互作用。对于这些snp，虽然单独的性选择往往导致等位基因频率的变化与自然选择的方向相同，但当自然选择和性选择同时发生时，等位基因频率的变化大大减少甚至逆转。这表明自然选择和性选择之间的对抗源于雄性对雌性的伤害。行为实验表明，雄性倾向于追求和交配高适应性的雌性，而雄性注意力的增加所带来的危害消除了雌性的适应性优势。在我们的实验中，携带其他适应性等位基因的女性可能因此不成比例地遭受男性引起的伤害，因为她们的性吸引力增加了。这些结果表明，当交配系统涉及性冲突和雄性配偶偏好时，一类其他适应性突变可能不会促进适应。
Sexual selection is widely appreciated for generating remarkable phenotypic diversity [1, 2], but its contribution to adaptation and the purging of deleterious mutations is unresolved [3]. To provide insight into the impact of sexual selection on naturally segregating polymorphisms across the genome, we previously evolved 12 populations of Drosophila serrate in a novel environment employing a factorial manipulation of the opportunities for natural and sexual selection [4]. Here, we genotype more than 1,400 SNPs in the evolved populations and reveal that sexual selection affected many of the same genomic regions as natural selection, aligning with it as often as opposing it. Intriguingly, more than half of the 80 SNPs showing treatment effects revealed an interaction between natural and sexual selection. For these SNPs, while sexual selection alone often caused a change in allele frequency in the same direction as natural selection alone, when natural and sexual selection occurred together, changes in allele frequency were greatly reduced or even reversed. This suggests an antagonism between natural and sexual selection arising from male-induced harm to females [5]. Behavioral experiments showed that males preferentially courted and mated with high-fitness females, and that the harm associated with this increased male attention eliminated the female fitness advantage. During our experiment, females carrying otherwise adaptive alleles may therefore have disproportionally suffered male-induced harm due to their increased sexual attractiveness. These results suggest that a class of otherwise adaptive mutations may not contribute to adaptation when mating systems involve sexual conflict and male mate preferences.