Gañán Natalia, Sanchez-Rodriguez Ana, Roldan Eduardo R S
Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (CSIC), 28006 Madrid, Spain.
Animals (Basel). 2025 Mar 26;15(7):949. doi: 10.3390/ani15070949.
Sperm cryopreservation is a powerful tool for the conservation of endangered species, but its application requires adapting protocols to particular species, due to differences in sperm structure, function, and cryosensitivity. Research on the biology of endangered felids primarily relies on the domestic cat as an experimental model. Semen from live animals can be collected using several methods. However, in animals that die due to roadkill or in the field, spermatozoa must be retrieved from the epididymis. Differences may exist in the cryosensitivity of epididymal and ejaculated sperm due to the influence of secretions from accessory genital glands. We analyzed the effects of several factors on the motility and acrosomal integrity of cryopreserved cat epididymal spermatozoa, including cooling rate, storage system, time and temperature of straw loading, and the freezing method in nitrogen vapors. There were no significant differences in motility or acrosomal integrity at thawing between fast (-0.5 °C/min) or slow (-0.125 °C/min) cooling rates or between loading straws at room temperature versus 5 °C. Post-thaw motility was significantly higher when using straws compared to pellets and when freezing in nitrogen vapors at two levels rather than at a single level. Additionally, interactions between the loading temperature of straws and both motility and acrosomal integrity were not significant. These results are important for standardizing protocols to cryopreserve feline epididymal sperm, facilitating the rescue of genetic material from endangered species in the field.
精子冷冻保存是保护濒危物种的一项有力工具，但其应用需要根据特定物种调整方案，因为精子的结构、功能和冷冻敏感性存在差异。对濒危猫科动物生物学的研究主要依赖家猫作为实验模型。可使用多种方法采集活体动物的精液。然而，对于因路杀或在野外死亡的动物，必须从附睾中获取精子。由于附属生殖腺分泌物的影响，附睾精子和射出精子的冷冻敏感性可能存在差异。我们分析了几个因素对冷冻保存的猫附睾精子活力和顶体完整性的影响，包括降温速率、储存系统、细管装填时间和温度以及在氮气中冷冻的方法。快速（-0.5℃/分钟）或缓慢（-0.125℃/分钟）降温速率之间，或在室温与5℃下装填细管之间，解冻时的活力或顶体完整性没有显著差异。与颗粒相比，使用细管时解冻后的活力显著更高，并且在两个水平而非单个水平的氮气中冷冻时也是如此。此外，细管装填温度与活力和顶体完整性之间的相互作用不显著。这些结果对于规范猫附睾精子冷冻保存方案很重要，有助于从野外濒危物种中抢救遗传物质。
