Abstract：
Sexual selection is known to play a major role in the evolution of insect sperm size, whereas natural selection is thought to be a major driver of insect egg size. Despite these differing forms of selection operating, it is possible coevolution between male and female gametes can occur owing to their vital interactions during fertilization. We tested egg-sperm coevolution in insects and found that longer sperm correlated to longer and wider eggs. Moreover, the size of the entry point of sperm into insect eggs (micropyles), was positively related to the diameter of sperm, on average being approximately three times the diameter of the sperm. This suggests a function in reducing and channelling sperm entry, but potentially still leaving space for movement. Our work suggests that greater attention needs to be paid to egg-sperm interactions prior to the point of fertilization as they may influence the evolution of gametes.
摘要：
众所周知，性选择在昆虫精子大小的进化中起着重要作用，而自然选择被认为是昆虫卵大小的主要驱动因素。尽管有这些不同的选择操作形式，由于受精过程中的重要相互作用，雄性和雌性配子之间可能会发生共同进化。我们测试了昆虫中的卵-精子协同进化，发现更长的精子与更长和更宽的卵子相关。此外，精子进入昆虫卵的入口点的大小（微孔），与精子直径呈正相关，平均大约是精子直径的三倍。这表明了减少和引导精子进入的功能，但仍有可能为运动留出空间。我们的工作表明，在受精之前需要更多地关注卵子-精子的相互作用，因为它们可能会影响配子的进化。
