Sulzyk Valeria, Curci Ludmila, González Lucas N, Rebagliati Cid Abril, Weigel Muñoz Mariana, Cuasnicu Patricia S
Instituto de Biología y Medicina Experimental (IByME-CONICET), Buenos Aires, Argentina.
Elife. 2025 Apr 28;13:RP97105. doi: 10.7554/eLife.97105.
Numerous reports showed that the epididymis plays key roles in the acquisition of sperm fertilizing ability but its contribution to embryo development remains less understood. Female mice mated with males with simultaneous mutations in and genes exhibited normal fertilization but impaired embryo development. In this work, we found that this phenotype was not due to delayed fertilization, and it was observed in eggs fertilized by epididymal sperm either or . Of note, eggs fertilized by mutant sperm displayed impaired meiotic resumption unrelated to Ca oscillations defects during egg activation, supporting potential sperm DNA defects. Interestingly, cauda but not caput epididymal mutant sperm exhibited increased DNA fragmentation, revealing that DNA integrity defects appear during epididymal transit. Moreover, exposing control sperm to mutant epididymal fluid or to Ca-supplemented control fluid significantly increased DNA fragmentation. This, together with the higher intracellular Ca levels detected in mutant sperm, supports a dysregulation in Ca homeostasis within the epididymis and sperm as the main factor responsible for embryo development failure. These findings highlight the contribution of the epididymis beyond fertilization and identify CRISP1 and CRISP3 as novel factors essential for sperm DNA integrity and early embryo development.
大量报告表明，附睾在精子获得受精能力方面发挥着关键作用，但其对胚胎发育的贡献仍知之甚少。与同时具有 和 基因双突变的雄性小鼠交配的雌性小鼠，受精过程正常，但胚胎发育受损。在这项研究中，我们发现这种表型并非由于受精延迟，并且在由附睾精子 或 受精的卵子中也观察到了这种现象。值得注意的是，由突变精子受精的卵子表现出减数分裂恢复受损，这与卵子激活过程中钙振荡缺陷无关，提示可能存在精子DNA缺陷。有趣的是，附睾尾部而非头部的突变精子DNA片段化增加，表明DNA完整性缺陷在附睾转运过程中出现。此外，将对照精子暴露于突变附睾液或添加钙的对照液中，显著增加了DNA片段化。这一点，连同在突变精子中检测到的较高细胞内钙水平，支持了附睾和精子内钙稳态失调是胚胎发育失败的主要原因这一观点。这些发现突出了附睾在受精之外的作用，并确定CRISP1和CRISP3是精子DNA完整性和早期胚胎发育所必需的新因子。
