Cortés-Gutiérrez E I, Crespo F, Gosálvez A, Dávila-Rodríguez M I, López-Fernández C, Gósalvez J
Department of Genetics, Nothwest Research Center of Biology, Mexican National Institute for Health, 64720 Monterrey, Mexico.
Theriogenology. 2008 May;69(8):1022-32. doi: 10.1016/j.theriogenology.2008.02.002. Epub 2008 Mar 25.
The dynamics of sperm DNA fragmentation (sDF) and sperm viability were analyzed in frozen-thawed sperm samples of Equus asinus (Zamorano-Leonés), a breed at risk of extinction. Sperm DNA fragmentation was assessed using an adaptation of the sperm chromatin dispersion test developed for stallions in five different frozen samples. Sperm were thawed and incubated at different temperatures (37 degrees C, 25 degrees C, and 4 degrees C) and sDF was assessed at different times and compared. The mean sDF after thawing at the beginning of the experiment was 18.20+/-14.77% and did not differ significantly from the results of a neutral comet assay (22.0+/-19.34%). The tendency in the sDF of all donkeys indicated that sperm DNA is more sensitive to breakage when incubated at 37 degrees C than when incubated at 25 degrees C or 4 degrees C. Interestingly, the tendency was not the same when different animals were compared, and differences in sDF dynamics were established among individuals. sDF correlated negatively with sperm viability in some individuals but not in others. From a conservation perspective, sDF analysis may offer a new way to assess sperm quality in endangered breeds in order to identify and select the best semen samples for artificial reproduction purposes. In particular, we recommend for artificial insemination the use of semen samples with a slow increase in sDF with time after thawing.
对濒临灭绝的萨莫拉诺-莱昂内斯驴（Equus asinus）冻融精子样本中的精子DNA碎片化（sDF）动态和精子活力进行了分析。使用为种马开发的精子染色质扩散试验的改良方法，对五个不同冷冻样本中的精子DNA碎片化进行了评估。精子解冻后在不同温度（37摄氏度、25摄氏度和4摄氏度）下孵育，并在不同时间评估sDF并进行比较。实验开始时解冻后的平均sDF为18.20±14.77%，与中性彗星试验结果（22.0±19.34%）无显著差异。所有驴的sDF趋势表明，精子DNA在37摄氏度下孵育时比在25摄氏度或4摄氏度下孵育时对断裂更敏感。有趣的是，比较不同动物时趋势并不相同，个体之间sDF动态存在差异。在一些个体中sDF与精子活力呈负相关，而在其他个体中则不然。从保护角度来看，sDF分析可能为评估濒危品种的精子质量提供一种新方法，以便识别和选择用于人工繁殖目的的最佳精液样本。特别是，我们建议人工授精使用解冻后sDF随时间缓慢增加的精液样本。
