Divergent artificial selection for female reproductive investment has a sexually concordant effect on male reproductive success

Depending on the genetic architecture of male and female fitness, sex-specific selection can have negative, positive or neutral consequences for the opposite sex. Theory predicts that conflict between male and female function may drive the breakdown of intrasexual genetic correlations, allowing sexual dimorphism in sexually antagonistic traits. Reproductive traits are the epitome of this, showing highly differentiated proximate functions between the sexes. Here we use divergent artificial selection lines for female reproductive investment to test how female-specific selection on a sex-limited trait affects male reproductive success in a precocial bird, the Japanese quail (Coturnix japonica). We demonstrate that selection for increased egg investment in females positively affects male reproductive success both in competitive and non-competitive mating situations. This increased reproductive success was linked to a relatively larger left testis in males originating from lines selected for...

基于雌雄适合度的遗传结构（genetic architecture of male and female fitness），性别特异性选择（sex-specific selection）可对异性产生负面、正面或中性的影响。理论预测，雌雄功能间的冲突可能会打破性内遗传相关性（intrasexual genetic correlations），使性拮抗性状（sexually antagonistic traits）演化出性别二态性。生殖性状正是这一演化现象的典型代表，其在雌雄个体间展现出高度分化的近因功能。本研究针对雌性生殖投入构建了差异化人工选择品系（divergent artificial selection lines），以此检验早成鸟类（precocial bird）——日本鹌鹑（Coturnix japonica）中，针对性别限制性状（sex-limited trait）的雌性特异性选择如何影响雄性生殖成功率。研究结果证实，在雌性群体中选择提升产卵投入，无论在竞争性还是非竞争性交配情境下，均能正向提升雄性生殖成功率。这种提升的生殖成功率，与源自该选择品系的雄性个体相对更大的左侧睾丸存在关联。