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

Background: Despite the common assumption that multiple mating 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 opportunity for mating in replicate populations of Drosophila melanogaster by removing components of 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 state. The post-mating gene expression profiles of monogamous females differ significantly from promiscuous females, involving 9% of the genes tested (approximately 6% of total genes in D. melanogaster). 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更倾向于多次交配，而雌性则并非如此，但迄今为止，关于多次交配对雌性适合度的整体影响尚未达成共识。值得注意的是，目前关于雌性应对性选择压力的遗传与生理基础，所知甚少。本研究结合实验演化手段与基因组学技术，探究单次与多次交配对雌性繁殖力及基因表达的影响。我们通过移除性选择相关组分，对重复的黑腹果蝇（Drosophila melanogaster）种群的交配机会进行实验操控，旨在检验不同交配策略下演化出的雌性的短期交配后效应差异。

研究结果：结果显示，单配偶制雌性的繁殖力出现下降，而通过实验将选择压力逆转回祖先状态后，该下降趋势可得到部分恢复。单配偶制雌性的交配后基因表达谱与多配偶制雌性存在显著差异，涉及9%的检测基因（约占黑腹果蝇总基因数的6%）。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、繁殖活动及信号通路调控。

研究结论：本研究结果阐明了不同交配系统下雌性交配后响应的演化机制，并通过识别出与无多配偶选择环境下雌性繁殖力下降相关的候选基因列表，为雌性受性选择靶向的基因提供了全新见解。