卵裂期胚胎中的凋亡征象及其与胚胎形态的关系

目的 评估体外授精的人卵裂期胚胎中是否存在凋亡,探讨卵裂期胚胎的凋亡征象与胚胎形态之间的关系.方法 结合末端脱氧核苷酸转移酶介导dUTP缺口末端标记法(TUNEL)原位检测DNA凋亡和测定Caspase 3的表达水平,检测人卵裂期胚胎中的凋亡.并分析卵裂期胚胎中胞质碎片占胚胎总体积的比例和发育速度与TUNEL阳性率和Caspase 3的表达强度之间的关系.结果 碎片比>20%组胚胎的凋亡率明显高于碎片比≤20%的胚胎(P<0.01),Caspase 3平均荧光强度在碎片比>50%组明显升高(P<0.05).发育正常、迟缓和停滞胚胎之间胚胎凋亡率差异无显著性意义.发育停滞组的Caspase 3平均荧光强度高于发育正常和迟缓组(P<0.05).结论 人体外授精的卵裂期胚胎中存在凋亡征象,凋亡主要与胞质碎片有关,胚胎发育停滞可能是胚胎凋亡的早期表现.

Apoptosis of Cleavage Stage Embryos in IVF-ET and Its Association with Embryo Morphology

Objective To evaluate whether apoptosis exists in human cleavage stage embryos from in vitro fertilization and the relationship between apoptosis in cleavage stage embryos and morphological characteristics on D3.Methods Apoptosis of human cleavage stage embryos and the expression of Caspase 3 were detected by using the terminal transferase-mediated DNA end labeling(TUNEL) assay.The TUNEL-positive rate and the average fluorescent intensity were determined according to the fragmentation rate and developmental rate.Results Apoptosis rate in embryos with>20% fragmentation was significantly higher than that in other groups(P<0.01).The average fluorescent intensity was significantly increased in embryos with>50% fragmentation(P<0.05).There was no significant difference in apoptosis rate among the normal developmental embryos,slow developmental embryos and arrested embryos.The average fluorescent intensity in arrested embryos was strong than that in the normal developmental embryos and slow developmental embryos(P<0.05).Conclusion Apoptosis does exist in cleavage stage embryos from in vitro fertilization.Apoptosis in cleavage stage embryo is strongly correlated with cellular fragments.The early developmental arrest of the human preimplantation embryos may be the early phenomenon of apoptosis.