Hu Jian-hong, Li Qing-wang, Jiang Zhong-liang, Li Wen-ye
College of Animal Science and Technology, Northwest A & F University, Yangling, ShaanXi Province 712100, PR China.
Cryobiology. 2008 Dec;57(3):257-62. doi: 10.1016/j.cryobiol.2008.09.004. Epub 2008 Sep 19.
The sperm-rich fraction, collected from eight mature Yorkshire boars, was frozen in an extender containing 9% LDL (w/v), 100mM trehalose, or 20% yolk (v/v), respectively. Sperm DNA integrity was assessed using the single-cell gel electrophoresis (SCGE). Other sperm quality characteristics such as motility, acrosome and membrane integrity were also monitored. The results showed that freezing-thawing caused an increase in sperm DNA fragmentation, and extender containing 9% LDL could significantly protect sperm DNA integrity (P<0.05) from the damage caused by cryopreservation and decrease DNA damages compared with extender containing 100mM trehalose and 20% yolk (v/v). No significant difference in damaged DNA was detected between frozen and unfrozen semen samples for extender of 9% LDL and 100mM trehalose, but cryopreservation could increase the degree of DNA damage (P<0.05), the percentage of damaged DNA degree of grade 2 and 3 was significantly increased. The deterioration in post-thaw sperm DNA integrity was concurrent with reduced sperm characteristics. The data here demonstrated that the cryoprotectant played a fundamental role in reducing boar sperm DNA damage and protecting DNA integrity. It can be suggested that evaluation of sperm DNA integrity, coupled with correlative and basic characteristics such as motility, acrosome integrity and membrane integrity, may aid in determining the quality of frozen boar semen.
从八头成年约克夏公猪采集富含精子的部分，分别冷冻于含有9%低密度脂蛋白（w/v）、100mM海藻糖或20%蛋黄（v/v）的稀释液中。使用单细胞凝胶电泳（SCGE）评估精子DNA完整性。还监测了其他精子质量特征，如活力、顶体和膜完整性。结果表明，冻融导致精子DNA片段化增加，与含有100mM海藻糖和20%蛋黄（v/v）的稀释液相比，含有9%低密度脂蛋白的稀释液可显著保护精子DNA完整性（P<0.05）免受冷冻保存造成的损害并减少DNA损伤。对于含有9%低密度脂蛋白和100mM海藻糖的稀释液，冷冻和未冷冻精液样本之间未检测到受损DNA的显著差异，但冷冻保存会增加DNA损伤程度（P<0.05），2级和3级受损DNA程度的百分比显著增加。解冻后精子DNA完整性的恶化与精子特征的降低同时发生。此处的数据表明，冷冻保护剂在减少公猪精子DNA损伤和保护DNA完整性方面起着重要作用。可以认为，评估精子DNA完整性，结合活力、顶体完整性和膜完整性等相关基本特征，可能有助于确定冷冻公猪精液的质量。
