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.精子形态即便在亲缘关系相近的物种间也极具多样性，而雌雄双方的受精识别系统协同演化，是成功完成核融合（karyogamy，即雌雄原核融合）的必要前提。多数物种在受精过程中会将整个精子送入卵细胞内，因此精子形态多样性可能会影响核融合所需的细胞内精卵互作（intracellular sperm-egg interactions, ISEIs）。我们以多种果蝇（Drosophila）物种为研究对象，定量测定了核融合前后卵细胞内的精子形态变异，以探究精子形态演化是否会对细胞内精卵互作产生影响。我们测定了7项用于描述细胞内精卵互作的参数，以探究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。我们通过异种杂交实验，检验了雄性亲本来源、雌性亲本来源以及雌雄互作在决定细胞内精卵互作过程中的相对作用。研究发现，同一物种内的精子形态会随发育进程发生变化，且在特定发育阶段，不同物种的部分细胞内精卵互作指标存在差异。亲本来源对部分细胞内精卵互作指标存在影响，整体呈现出雌性亲本来源效应更强的普遍趋势。综上，本研究明确了不同物种间细胞内精卵互作的保守性与变异性，并证明了其可为配子演化与发育研究提供新的认知参考。