不同冷冻载体对小鼠成熟卵母细胞玻璃化冷冻的影响

Effect of different cryopreservative carriers on vitrification of mouse MⅡ oocytes

目的:探讨玻璃化冷冻小鼠成熟减数第二次分裂中期(MⅡ期)卵母细胞的最佳冷冻载体及冷冻方法。方法:用乙二醇和蔗糖为玻璃化冷冻保护剂,将小鼠成熟MⅡ期卵母细胞分为冻融、暴露和对照组。冻融组分别采用普通麦管、封闭式拉细麦管(CPS)和开放式拉细麦管(OPS)作载体,采用玻璃化快速冷冻和快速复温的方法冻存小鼠成熟卵母细胞;暴露组卵母细胞仅暴露在冷冻和复苏液中,不进行冷冻;对照组卵母细胞不接触冷冻和复苏液。观察各组处理后卵子回收、受精、卵裂等情况。结果:冻融组普通麦管、CPS和OPS处理的卵母细胞回收率分别为92.0%、92.3%和72.3%,OPS处理卵母细胞的回收率显著低于普通麦管和CPS处理的卵母细胞(P<0.001);普通麦管、CPS和OPS处理的卵母细胞复苏存活率分别为43.5%、72.2%和76.5%,CPS和OPS处理卵母细胞的复苏存活率显著高于普通麦管组处理的卵母细胞(P<0.001)。冻融、暴露和对照组的卵裂率分别为38.6%、69.2%和73.5%,冻融组显著低于暴露和对照组(P<0.001)。结论:CPS法在玻璃化冷冻保存成熟的卵母细胞方面有价值。

Aim ：To explore the optimal carrier and procedure for mouse mature （ M Ⅱ ） oocyte vitrification. Methods ： Collected mouse M Ⅱ ooeytes and randomly divided into experimental, exposed, and control groups. Three types of carriers [ regular straws,closed pulled straws （CPS）, and open pulled straws （OPS）] were used in expreimental group. Ethylene glycol and sucrose were used as cryopreservatives to flash freeze and thaw the ooeytes in experimental group. The ooeytes in the exposed group were only exposed to ethylene glycol and sucrose but not frozen and the oocytes in the control group were not treated. The post-thawed oocyte retrieval rate, fertilized rate, and cleavage rate were observed after vitrification. Results ： Ooeyte retrieval rates were 92.0% , 92.3% , and 72.3% in regular straws, OPS, and CPS treatment oocytes, respectively. Oocyte retrieval rate in the CPS treatment oocytes was much lower compared with the other two treatment oo- cytes （ P 〈 0. 001 ）. Post-thawed oocyte survival rates were 43.5% , 72.2% , and 76.5% in regular straws, CPS, and OPS treatment oocytes,respectively. The rates of CPS and OPS treatment oocytes were much higher in comparison to the regular straw treatment oocytes（ P 〈 0. 001 ）. The cleavage rates in experimental, exposed, and control groups were 38.6% , 69.2% , and 73.5% ,respectively. The cleavage rate of experimental group was much lower than those of the exposed and control groups （ P 〈 0. 001 ）. Conclusion ： CPS is a promising carrier in vitrification for mouse M Ⅱ oocytes and worth trying to put into application.