Data from: Sperm morphology and the evolution of intracellular sperm-egg interactions

Sperm morphology is incredibly diverse, even among closely related species, yet the coevolution between males and females of fertilization recognition systems is necessary for successful karyogamy (male and female pronuclear fusion). In most species, the entire sperm enters the egg during fertilization so sperm morphological diversity may impact the intra-cellular sperm-egg interactions necessary for karyogamy. We quantified morphological variation of sperm inside eggs prior to and following karyogamy in several species of Drosophila to understand whether evolution of sperm morphology could influence intracellular sperm-egg interactions (ISEIs). We measured seven parameters that describe ISEIs among species to determine whether these parameters varied both within a species across development and across species at the same developmental stage. We used heterospecific crosses to test the relative role of male origin, female origin and interaction between the male and female in determining ISEIs. We found that sperm shape changed within a species as development proceeded and, at particular development stages, species varied in some ISEIs. Parental origin had an effect on some ISEIs, with a general trend for a stronger female effect. Overall, our findings identify conserved and variable ISEIs among species and demonstrates the potential to contribute understanding to gamete evolution and development.精子形态即使在亲缘关系较近的物种间也呈现出极高的多样性，而受精识别系统的雌雄协同演化，对于成功完成核配（karyogamy，即雌雄原核融合）至关重要。在多数物种的受精过程中，整个精子会进入卵细胞，因此精子形态多样性可能会影响核配所需的胞内精卵相互作用。本研究以多种果蝇为研究对象，定量分析了核配前后卵细胞内精子的形态变异，以探究精子形态演化是否会对胞内精卵相互作用（intracellular sperm-egg interactions, ISEIs）产生影响。我们测定了7项用于描述ISEIs的参数，旨在明确这些参数在同一物种的不同发育阶段间，以及同一发育阶段的不同物种间是否存在差异。我们通过种间杂交实验，检验了雄性来源、雌性来源以及雌雄互作在决定ISEIs过程中的相对作用。研究结果显示，同一物种内的精子形态会随发育进程发生改变；且在特定发育阶段，不同物种的部分ISEIs存在显著差异。亲本来源对部分ISEIs存在影响，整体呈现出雌性来源效应更强的普遍趋势。综上，本研究明确了不同物种间ISEIs的保守性与变异性，为理解配子演化与发育过程提供了有益的参考与新的研究视角。