Divergent allocation of sperm and the seminal proteome along a competition gradient in Drosophila melanogaster
Divergent allocation of sperm and the seminal proteome along a competition gradient in Drosophila melanogaster
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DOI：
10.1073/pnas.1906149116
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发表时间：
2019-09-03
影响因子：
11.1
通讯作者：
Wigby, Stuart
中科院分区：
文献类型：
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作者：
Hopkins, Ben R.;Sepil, Irem;Wigby, Stuart
精子竞争倾向于大量的、昂贵的射精，理论预测了分配策略的演变，使男性能够根据精子竞争的威胁来调整射精支出。虽然更大的精子转移，以应对精子竞争的风险增加的感知得到了很好的支持，我们有一个穷人的理解男性（i）对精子竞争的感知强度的变化，（ii）使用相同的分配规则的精子和精液，（iii）经验的变化，在当前和未来的生殖性能作为射精成分的变化。结合定量蛋白质组学与荧光精子标记，我们表明，果蝇雄性运动的精子和精液蛋白质（SFPs）的转移在不同水平的雄性-雄性竞争的独立控制。虽然精子转移在低竞争下达到峰值，但与基于精子竞争强度的一些理论预测一致，转移的SFP的丰度通常在高竞争水平下增加。然而，我们发现，SFPs的集群在它们对竞争的反应的方向性和敏感性方面有所不同，从而促进精液中成分的变化。通过跟踪男性交配概率和后代生产在连续交配下降的程度，我们提供的证据表明，射精成分的变化代表了一种适应性反应，目前spermcompetition，但一个是在未来的交配性能的成本。我们的工作揭示了射精成分分配规则中以前未知的差异，暴露了射精投资增加的下游成本，并最终表明射精成分可塑性在性选择中发挥着核心作用。
Sperm competition favors large, costly ejaculates, and theory predicts the evolution of allocation strategies that enable males to plastically tailor ejaculate expenditure to sperm competition threat. While greater sperm transfer in response to a perceived increase in the risk of sperm competition is well-supported, we have a poor understanding of whether males (i) respond to changes in perceived intensity of sperm competition, (ii) use the same allocation rules for sperm and seminal fluid, and (iii) experience changes in current and future reproductive performance as a result of ejaculate compositional changes. Combining quantitative proteomics with fluorescent sperm labeling, we show that Drosophila melanogaster males exercise independent control over the transfer of sperm and seminal fluid proteins (SFPs) under different levels of male-male competition. While sperm transfer peaks at low competition, consistent with some theoretical predictions based on sperm competition intensity, the abundance of transferred SFPs generally increases at high competition levels. However, we find that clusters of SFPs vary in the directionality and sensitivity of their response to competition, promoting compositional change in seminal fluid. By tracking the degree of decline in male mating probability and offspring production across successive matings, we provide evidence that ejaculate compositional change represents an adaptive response to current spermcompetition, but one that comes at a cost to future mating performance. Our work reveals a previously unknown divergence in ejaculate component allocation rules, exposes downstream costs of elevated ejaculate investment, and ultimately suggests a central role for ejaculate compositional plasticity in sexual selection.