Data from: Physiological maturation lags behind behavioral maturation in newly eclosed Drosophila melanogaster males

The accessory gland (AG) produces seminal fluid proteins that are transferred to the female upon mating in many insects. These seminal fluid proteins often promote a male’s post-copulatory reproductive success. Despite its crucial function many males eclose with a small gland not yet containing the full set of proteins. Thus, they need a physiological maturation period. Using Drosophila melanogaster we tested whether this physiological maturation is linked to behavioral maturation in males and to what extent seminal fluid allocation patterns are influenced by physiological maturation. To that end, we measured AG protein content (as a proxy for physiological maturation) of young, immature males that were either successful in gaining a mating, but prevented from transferring seminal fluid proteins, or unsuccessful, thus using mating success as a proxy for behavioral maturation. Furthermore, we compared ejaculate allocation in immature and mature males in a single mating. Though mating success and gland maturation increase with male age, we found no evidence for a fine-tuned synchronization of behavioral and physiological maturation in males. This is especially surprising since we found reduced ejaculate allocation in very young, immature males, hinting at reduced fitness benefits from early matings in D. melanogaster.在多数昆虫中，副性腺（accessory gland, AG）可合成精浆蛋白（seminal fluid proteins），这类蛋白会在交配过程中转移至雌性体内。这类精浆蛋白通常可提升雄性的交配后生殖成功率。尽管副性腺功能至关重要，但许多雄性个体羽化时，其副性腺体积较小且尚未具备完整的蛋白组分，因此需要经历一段生理成熟期。本研究以黑腹果蝇（Drosophila melanogaster）为实验对象，探究雄性的生理成熟是否与其行为成熟存在关联，以及生理成熟对精浆分配模式的影响程度。为此，我们针对幼年未成熟的雄性个体，测定其副性腺的蛋白含量（作为生理成熟的替代指标）；这些雄性要么成功完成交配但被阻止转移精浆蛋白，要么未能成功交配，由此将交配成功率作为行为成熟的替代指标。此外，我们还对比了未成熟与成熟雄性在单次交配中的射精分配情况。尽管雄性的交配成功率与副性腺成熟程度均随年龄增长而提升，但我们未发现雄性行为成熟与生理成熟存在精细同步调控的证据。这一结果尤为出人意料，因为我们发现极年轻的未成熟雄性的射精分配量有所降低，这暗示在黑腹果蝇中，早期交配所能带来的适合度收益会有所下降。