Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3SZ, UK.
Center for Reproductive Evolution, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
Sci Rep. 2019 Apr 10;9(1):5852. doi: 10.1038/s41598-019-41336-5.
Theory predicts that males will strategically invest in ejaculates according to the value of mating opportunities. While strategic sperm allocation has been studied extensively, little is known about concomitant changes in seminal fluid (SF) and its molecular composition, despite increasing evidence that SF proteins (SFPs) are fundamental in fertility and sperm competition. Here, we show that in male red junglefowl, Gallus gallus, along with changes in sperm numbers and SF investment, SF composition changed dynamically over successive matings with a first female, immediately followed by mating with a second, sexually novel female. The SF proteome exhibited a pattern of both protein depletion and enrichment over successive matings, including progressive increases in immunity and plasma proteins. Ejaculates allocated to the second female had distinct proteomic profiles, where depletion of many SFPs was compensated by increased investment in others. This response was partly modulated by male social status: when mating with the second, novel female, subdominants (but not dominants) preferentially invested in SFPs associated with sperm composition, which may reflect status-specific differences in mating rates, sperm maturation and sperm competition. Global proteomic SF analysis thus reveals that successive matings trigger rapid, dynamic SFP changes driven by a combination of depletion and strategic allocation.
理论预测，雄性会根据交配机会的价值来策略性地投资精液。虽然已经广泛研究了策略性精子分配，但对于精液（SF）及其分子组成的伴随变化却知之甚少，尽管越来越多的证据表明 SF 蛋白（SFPs）在生育力和精子竞争中是至关重要的。在这里，我们表明，在雄性红原鸡（Gallus gallus）中，随着精子数量和 SF 投资的变化，SF 成分在与第一只雌性连续交配后会动态变化，紧接着立即与第二只性新雌性交配。SF 蛋白质组表现出一种蛋白质耗竭和富集的模式，包括免疫和血浆蛋白的逐渐增加。分配给第二只雌性的精液具有独特的蛋白质组学特征，其中许多 SFPs 的耗竭被其他 SFP 的增加所补偿。这种反应部分受到雄性社会地位的调节：当与第二只新雌性交配时，亚优势者（但不是优势者）优先投资于与精子组成相关的 SFPs，这可能反映了在交配率、精子成熟和精子竞争方面的特定地位差异。因此，全球 SF 蛋白质组学分析表明，连续交配会引发快速、动态的 SFP 变化，这是由耗竭和策略性分配的结合所驱动的。
