OPS法玻璃化冷冻小鼠不同成熟时期卵母细胞的研究

目的比较OPS法玻璃化冷冻小鼠不同成熟时期卵母细胞解冻后体外成熟、体外受精及胚胎发育能力。方法收集ICR小鼠生殖泡期（GV）未成熟卵和成熟卵，分五组行OPS（open pulled straw，开放式拉细麦管）法玻璃化冷冻，Ⅰ组：直接冷冻GV期卵；Ⅱ组：GV期卵在体外培养8h后冷冻；Ⅲ组：GV期卵在体外培养16h后冷冻；Ⅳ组：GV期卵体外培养成熟（IVM）后冷冻；Ⅴ组：直接冷冻体内成熟卵。解冻后比较各组卵受精率、卵裂率及8细胞胚胎形成率。结果Ⅰ组（GV期卵）冷冻解冻后存活率达57．5％，显著高于Ⅱ组（34．1％），Ⅲ组（32．0％），Ⅳ组（29．6％）及Ⅴ组（31．0％）（P〈0．01）。各组体外受精率、卵裂率及8细胞胚胎形成率比较，差异不显著（P〉0．05）。结论采用OPS法玻璃化冷冻小鼠卵母细胞，冷冻GV期卵较冷冻其它成熟时期卵效果好。

Study on vitrification of mouse oocytes at different developmental stages by OPS

Objective： To examine the in vitro maturation （IVM）, in vitro fertilization （IVF） and embryo developmental capacity of thawed oocytes frozen at different developmental stages using open pulled straw. Methods ： The germinal vesicle （GV） and mature mouse oocytes were randomly divided into five groups for vitrification using open pulled straw （OPS）. Group Ⅰ： frozen at GV stage. Group Ⅱ： frozen after in vitro cuhure （IVC）8h. Group Ⅲ： frozen after IVC 16h. Group Ⅳ： frozen afterIVM. Group Ⅴ： frozen in vivo matured oocytes. Then the thawed oocytes were cultured to observed IVF, cleavage and 8 - cell rates. Results： The survival rate of oocytes frozen at GV stage was 57.5%. which was significantly higher than that of Group Ⅱ （34. 1% ）, Group Ⅲ （32.0%）, Group Ⅳ （29.6%） and Group Ⅴ （31.0%） （ P 〈 0. 01 ）. There was no significant difference in the rates of IVF, cleavage and 8 - cell between groups （ P 〉 0. 05 ）. Conclusion ： The mouse oocytes at GV stage could be more effectively vitrified using OPS than that at other developmental stages.