乙二醇降低超低温冷冻黄姑鱼精子的DNA损伤

为了解乙二醇(EG)为抗冻剂超低温冻存黄姑鱼(Nibea albiflora)精子的活力及DNA损伤情况,本研究以Hank′s盐溶液(HBSS)为稀释液,5%~30%乙二醇(EG)为抗冻剂,0.5 ml麦细管为冻存管,两步降温法超低温冷冻保存黄姑鱼精子,用显微观察法测定精子活力,用单细胞凝胶电泳技术(SCGE)检测精子的DNA损伤,用SPSS 11.5处理实验数据。黄姑鱼鲜精的激活率为85.67%±2.09%、运动时间为(318.67±6.11)s、寿命为(405.67±7.77)s。5%、10%、15%乙二醇(EG)组冻精的运动时间及寿命与鲜精相比差异不显著,其中10%乙二醇(EG)组冻精的激活率为84.67%±1.15%、运动时间为(319.00±12.12)s、寿命为(400.67±4.73)s;20%、25%、30%乙二醇(EG)组冻精的运动时间及寿命与鲜精相比差异显著。5%、10%、15%、20%乙二醇(EG)组冻精核DNA损伤状况与鲜精无显著差异,25%、30%乙二醇(EG)组冻精核DNA损伤状况与鲜精差异显著,且冻精核DNA的损伤程度与乙二醇(EG)浓度成正相关。分析认为,5%~15%乙二醇(EG)适宜作为黄姑鱼精子超低温冷冻保存用抗冻剂。

The DNA Damage of Cryopreserved Sperm Is Declined by Using Ethylene Glycol as a Cryoprotectant in Spotted Maigre (Nibea albiflora)

In this paper, we studied the spermatozoa cryopreservation of Nibea albiflora using two-step cooling methods, HBSS as extender, EG(ethylene glycol) as cryoprotectant, in 0.5mL straws, also investigated the DNA damage in response to the cryopreservation process by SCGE. The results showed that there were no significant differences between fresh sperm and frozen-thawed sperm which diluted with 5%, 10% or 15%EG in moving time and life-span time. However, frozen-thawed sperm moving time and life-span time with 20%, 25% or 30% EG as cryoprotectant had a significant drop as compared with fresh sperm. The SCGE results demonstrated that there were no significant differences between fresh sperm and frozen-thawed sperm which diluted with 5%, 10%, 15% or 20%EG in DNA fragments, but DNA fragments differed significantly with fresh sperm when EG concentrations was added to 25% or 30%. In fact, there was a positive correlation between DNA damage extent of frozen-thawed sperm and concentrations of EG in protocol. So we conclude that cryoprotectant of 5%~15%EG can be considered as the most effective choices for spermatozoa cryopreservation of Nibea albiflora.