Data from: Female responses to experimental removal of sexual selection in Drosophila melanogaster

Background: Despite the common assumption that promiscuity should in general be favored in males, but not in females, to date there is no consensus on the general impact of multiple mating on female fitness. Notably, very little is known about the genetic and physiological features underlying the female response to sexual selection pressures. By combining an experimental evolution approach with genomic techniques, we investigated the effects of single and multiple matings on female fecundity and gene expression. We experimentally manipulated the mating system in replicate populations of Drosophila melanogaster by removing sexual selection, with the aim of testing differences in short term post-mating effects of females evolved under different mating strategies. Results: We show that monogamous females suffer decreased fecundity, a decrease that was partially recovered by experimentally reversing the selection pressure back to the ancestral promiscuous state. The post-mating gene expression profiles of monogamous females differ significantly from promiscuous females, involving 9% of the genes tested. These transcripts are active in several tissues, mainly ovaries, neural tissues and midgut, and are involved in metabolic processes, reproduction and signaling pathways. Conclusions: Our results demonstrate how the female post-mating response can evolve under different mating systems, and provide novel insights into the genes targeted by sexual selection in females, by identifying a list of candidate genes responsible for the decrease in female fecundity in the absence of promiscuity.

研究背景：尽管学界普遍认为雄性的滥交行为总体上更受自然选择青睐，但雌性则并非如此，然而迄今为止，学界对于多配偶行为对雌性适合度（fitness）的整体影响尚未达成共识。值得注意的是，关于雌性应对性选择压力的遗传与生理机制，目前所知甚少。本研究结合实验演化（experimental evolution）手段与基因组学技术，探究了单次与多次交配对雌性繁殖力（fecundity）及基因表达的影响。我们通过移除黑腹果蝇（Drosophila melanogaster）重复种群的性选择，对其交配系统进行实验操控，以此检验在不同交配策略下演化出的雌性，其短期交配后效应的差异。
研究结果：本研究显示，实行单配偶制的雌性果蝇繁殖力下降，而通过实验将选择压力逆转回祖先的滥交状态后，该繁殖力损失得到了部分恢复。单配偶制雌性的交配后基因表达谱与滥交雌性存在显著差异，涉及9%的检测基因。这些转录本在多种组织中活跃表达，主要为卵巢、神经组织与中肠，且参与代谢过程、繁殖调控及信号通路活动。
研究结论：本研究结果揭示了雌性的交配后响应如何在不同交配系统下发生演化，并通过鉴定出无滥交情境下导致雌性繁殖力下降的候选基因列表，为雌性体内受性选择靶向的基因提供了全新见解。