Thayer Rachel C, Polston Elizabeth S, Hanna Giovanni, Begun David J
Department of Evolution and Ecology, University of California, Davis, CA, USA.
Mol Biol Evol. 2025 Sep 1;42(9). doi: 10.1093/molbev/msaf210.
Drosophila seminal fluid proteins (SFPs) are often cited as an example of interlocus sexual conflict, wherein the proteins increase male fitness while decreasing female fitness, spurring recurring female counter-adaptations and rapid molecular evolution. This model predicts that male-expressed genetic variation in the accessory gland, which produces seminal fluid, should generate counter-evolving genetic pathways in females, resulting in sexual coevolution. Using a trio of D. melanogaster populations exhibiting substantial SFP expression divergence due to recent selection, we test for coevolution in the female post-mating transcriptome in the lower reproductive tract and head. Contrasting predictions of sexual antagonism, female post-mating gene expression is indifferent to male population of origin. Instead, our results better support the alternative hypotheses that environmental variation is the source of selection on male SFP gene expression and that population differentiation in the female post-mating transcriptome is generated by female-expressed genotypic differentiation.
果蝇精液蛋白（SFPs）常被视为基因座间性冲突的一个例子，在这种冲突中，这些蛋白提高了雄性的适应性，却降低了雌性的适应性，从而引发雌性反复的反适应以及快速的分子进化。该模型预测，在产生精液的附腺中由雄性表达的遗传变异，应该会在雌性中产生反向进化的遗传途径，从而导致性协同进化。我们利用三个因近期选择而表现出精液蛋白表达存在显著差异的黑腹果蝇种群，测试了雌性下生殖道和头部在交配后的转录组中的协同进化情况。与性拮抗的预测相反，雌性交配后的基因表达对雄性的种群来源并不敏感。相反，我们的结果更好地支持了其他假设，即环境变异是雄性精液蛋白基因表达选择的来源，并且雌性交配后转录组中的种群分化是由雌性表达的基因型分化产生的。
