摘要目的 探讨第3天(D3)卵裂期胚胎不同形态学分型与线粒体DNA(mtDNA)拷贝数、线粒体膜电位(mt△Ψm)的关系.方法 选择2012年3月至2013年11月在华中科技大学同济医学院附属同济医院行体外受精-胚胎移植(IVF-ET)治疗的不孕症患者新鲜周期发育较差不适合移植的胚胎117个,以及IVF-ET成功顺利分娩后自愿丢弃的质量较好的双原核冷冻胚胎106个.根据卵裂期胚胎评分标准伊斯坦布尔共识,将卵裂期胚胎分为Ⅰ级冷冻胚胎组(n=64)、Ⅱ级冷冻胚胎组(n=42)和Ⅲ级新鲜胚胎组(即不能移植的胚胎;n=117).采用实时荧光定量PCR (real-time PCR)技术和共聚焦显微镜分别检测胚胎mtDNA拷贝数和mt△Ψm,比较D3不同形态学分型的胚胎mtDNA拷贝数、mt△Ψm的差异.结果 Ⅲ级新鲜胚胎组mtDNA拷贝数[(1.7±1.0)×105 copy/μl]和mt△Ψm(1.56±0.32)均明显低于Ⅰ级冷冻胚胎组[(3.4± 1.7)×105 copy/μl、2.66±0.21]和Ⅱ级冷冻胚胎组[(2.6±1.2)×105 copy/μl、1.80±0.32],分别比较,差异均有统计学意义(P均＜0.05);Ⅰ级冷冻胚胎组的mtDNA拷贝数和mt△Ψm均明显高于Ⅱ级冷冻胚胎组,分别比较,差异也均有统计学意义(P均＜0.05).结论 质量越好的D3胚胎mtDNA拷贝数和mt△Ψm越高.

abstractsObjective To explore the relationship between the embryo with the different morphological types in the third day and its mitochondrial copy number,the membrane potential.Methods Totally 117 embryos with poor development after normal fertilization and were not suitable transferred in the fresh cycle and 106 frozen embryos that were discarded voluntarily by infertility patients with in vitro fertilization-embryo transfer after successful pregnancy were selected.According to evaluation of international standard in embryos,all cleavage stage embryos were divided into class Ⅰ frozen embryo group (n=64),class Ⅱ frozen embryo group (n=42) and class Ⅲ fresh embryonic group (not transplanted embryos;n=117).Real-time PCR and confocal microscopy methods were used to detect mitochondrial DNA (mtDNA) copy number and the mitochondrial membrane potential of a single embryo.The differences between embryo quality and mtDNA copy number and membrane potential of each group were compared.Results The copy number of mtDNA and the mitochondrial membrane potential in class Ⅲ fresh embryonic group [(1.7± 1.0)× 105 copy/μl,1.56±0.32] were significantly lower than those in class Ⅰ frozen embryo group [(3.4±1.7)×105 copy/μl,2.66±0.21]and class Ⅱ frozen embryo group [(2.6± 1.2)× 105 copy/μl,1.80±0.32;all P＜0.05].The copy number of mtDNA and the mitochondrial membrane potential in class Ⅰ frozen embryo group were significantly higher than those in class Ⅱ frozen embryo group (both P＜0.05).Conclusion The mtDNA copy number and the mitochondrial membrane potential of embryos of the better quality embryo are higher.