【摘要】 目的 :探讨不同冻融方法对人类MⅡ期卵子结构及发育潜能的影响。方法 :共收集人MⅡ期卵子 186个 ,随机分为A、B、C三组冷冻。A组为带完整冠丘颗粒细胞的MⅡ期卵 ,其冷冻保护液含 0 .1M蔗糖 ;B组为不带冠丘颗粒细胞的MⅡ期卵 ,冷冻保护液中蔗糖浓度同A组 ;C组为不带冠丘颗粒细胞MⅡ期卵 ,冷冻保护剂中蔗糖浓度为0 .2M。对冷冻复苏后的卵子进行质量评估、显微授精及胚胎培养 ,并对部分卵进行染色体分析。结果 :( 1)带冠丘颗粒细胞的A组MⅡ期卵子冻融后的受精卵卵裂率显著高于B组 (P <0 .0 5 ) ;0 .2M蔗糖浓度冷冻的C组的卵存活率、优质卵率和卵裂率均高于B组 (P<0 .0 5 )。 ( 2 )冻融后MⅡ期卵子的核型分析未发现染色体数目异常 ,但发现有染色单体的缺失。结论 :带完整冠丘颗粒细胞不影响MⅡ期卵子的冻融效果 ,而且可能有助于保护卵子的发育潜能 ;在冷冻保护液中 ,0 .2M蔗糖浓度比 0 .1M更适合于MⅡ期卵子的冷冻 ;冷冻可能造成MⅡ期卵染色体结构的改变更多还原

【Abstract】 Objective:To study the effects of different cryopreservation methods on the potential developmental ability and observe chromosome changes of human frozen-thawed metaphase Ⅱ oocytes.Methods:186 oocytes were collected from the GIUT and IVF cycles.The selected MⅡ stage oocytes were divided randomly into three experimental groups:A,B and C.The oocytes in Group A were frozen with cumulus corona cells and 0.1M sucrose concentration in the cryoprotectant solution.Group B was frozen without any cumulus cell and with the same cryoprotectant as Group A.In Group C,cumulus cells were denuded from oocytes,and the cryoprotectant solution contained 0.2M sucrose.The qualitative evaluation were given to thawed oocytes.ICSI was applied to high quality oocytes followed by further zygotes and embryo culture.Part of the oocytes were prepared for chromosome analysis.Results:(1)The cleavage rates in Group A (82.35%) were significantly higher than Group B (38.46%) (P<0.05).The survival rates and cleavage rates in Group C with 0.2M sucrose concentration was significantly higher than that in Group B (82.61% VS 68.24%,P<0.05;76.92% VS 38.46%,P<0.05).More than that,there was significant difference in the rate of high quality thawed oocytes between Group C and Group B (78.26% VS 52.94%,P<0.01).(2)No chromosome number change was found in 8 frozen-thawed MⅡ stage oocytes,but chromatid loss happened in 3 karyotypes.Conclusion:Intact cumulus corona cells around the MⅡ oocytes can facilitate oocytes cryopreservation and benefit the cleavage.Our results indicate that increasing the sucrose concentration to 0.2M in the cryoprotectant solution improve MⅡoocytes cryopreservation.Slow-freezing method may change the chromosome structure of the MⅡoocytes.更多还原