Kawakami Renya, Matsumura Kentarou
Graduate School of Agriculture, Kagawa University, Kagawa, Japan.
Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Tokyo, Japan.
PLoS One. 2024 Dec 23;19(12):e0316008. doi: 10.1371/journal.pone.0316008. eCollection 2024.
The investment of males in reproductive traits is often associated with their age. For example, several empirical and theoretical studies have demonstrated that older males make greater investment in reproduction compared with younger males. However, with regards to post-copulatory sexual selection, male reproductive success might be influenced by decreasing sperm quality with male age and the interaction between aging and mating experience in males. However, only a few studies that investigated influences of male aging as well as male mating experience on their post-copulatory sexual selection. In this study, we investigated paternity success influenced by the post-copulatory sexual selection of males at different ages in the red flour beetle Tribolium castaneum. To investigate the effects of the mating experience, the paternity success of older males who had experienced multiple matings (mated male) was compared with older males who had not experienced mating (naive male). The results of this study revealed that paternity success was not affected by male aging. In fact, naive old males exhibited significantly higher paternity success compared with old males who had previously mated. These results suggest that an interaction between male aging and their mating experience affected their paternity success, but not male aging. Our study has demonstrated that male aging affects their reproductive success in a complex interaction of multiple factors in T. castaneum.
雄性在生殖特征上的投入往往与其年龄有关。例如，多项实证研究和理论研究表明，与年轻雄性相比，年长雄性在繁殖方面的投入更大。然而，关于交配后的性选择，雄性的繁殖成功率可能会受到随着年龄增长精子质量下降以及雄性衰老与交配经验之间相互作用的影响。然而，仅有少数研究调查了雄性衰老以及雄性交配经验对其交配后性选择的影响。在本研究中，我们调查了在赤拟谷盗Tribolium castaneum中，不同年龄雄性交配后的性选择对父权成功率的影响。为了研究交配经验的影响，将经历过多次交配的年长雄性（已交配雄性）的父权成功率与未经历过交配的年长雄性（未交配雄性）进行了比较。本研究结果表明，父权成功率不受雄性衰老的影响。事实上，未交配的年长雄性比之前已交配的年长雄性表现出显著更高的父权成功率。这些结果表明，雄性衰老与其交配经验之间的相互作用影响了它们的父权成功率，但不是雄性衰老本身。我们的研究表明，在赤拟谷盗中，雄性衰老在多种因素的复杂相互作用中影响其繁殖成功率。
