不同时期胚胎线粒体拷贝数与胚胎自身形态学分型的关系研究

目的:探讨人类不同形态学分型的卵裂期胚胎和囊胚与自身线粒体拷贝数的关系。方法:选择在生殖中心因女性双侧输卵管梗阻行体外受精-胚胎移植（IVF-ET）助孕顺利娩出健康胎儿后，自愿丢弃冷冻的卵裂期胚胎和囊胚用于科学研究。将冷冻的胚胎解冻复苏后，依据胚胎发育的时期，将所有胚胎分为卵裂期胚胎冷冻组（D3冷冻胚胎组，n=63）和囊胚冷冻组（D5冷冻胚胎，n=82），再根据冷冻胚胎的形态学评分标准，将冷冻卵裂期胚胎分为优质胚胎组（n=38）和较差胚胎组（n=25），将冷冻囊胚分为优质囊胚组（n=52）和较差囊胚组（n=30）。采用实时PCR检测胚胎线粒体拷贝数，比较不同阶段胚胎和相同阶段不同质量的胚胎与自身线粒体拷贝数的差异。结果:D3冷冻胚胎组线粒体拷贝数明显低于D5冷冻胚胎组（t=9.34，P<0.02），D3冷冻胚组中优质胚胎mtDNA拷贝数高于质量较差胚胎组（t=6.62，P<0.01），D5冷冻胚组中优质胚胎mt DNA拷贝数明显高于质量较差胚胎组（t=8.03，P<0.04）。结论:不同时期胚胎mt DNA拷贝数对胚胎的发育潜能有重要影响，mtDNA拷贝数越高，胚胎质量越好。

Study on the relationship between the mitochondrial copy number of embryos at different stages and the morphological types of embryos

Objective: To study the relationship between mitochondrial copy number and embryos of different forms and types in different periods of human beings. Methods:Frozencleavage stage embryos and blastocysts voluntarily discarded for scientific research after successful pregnancy assisted by in vitro fertilization -embryo transfer （IVF-ET）in the reproductive center due to female bilateral fallopian tube obstructionwere selected. After thawing and recovery of frozen embryos，according to the different embryonic development period，all the embryos points D3 frozen embryos （cleavage stage embryo，n=63） and D5 frozen embryos group （blastocysts，n=82），and then based on the criteria of frozen embryos，frozen cleavage stage embryos can be divided into high quality embryos（n=38） and poor embryo group（n=25），frozen blastula were divided into poor quality blastocyst groups（n=52） and blastocyst groups （n=30）. Real-time PCR was used to detect the mitochondrial copy number of single embryo，and the differences of mitochondrial copy number between embryos at different stages and embryos of different quality at the same stage and their own mitochondria were compared. Results:D3 frozen embryos group of mt DNA copy number was lower than that in group D5 frozen embryos，the difference was statistically significant（t=9.34，P< 0.02），D3 group of frozen embryo quality embryos mtDNA copy number higher than that of poor quality embryos group，difference was statistically significant（t=6.62，P< 0.01），D5 group of frozen embryo quality embryos mtDNA copy number significantly higher than the poor quality embryos group，difference was statistically significant（t=8.03，P< 0.04）. Conclusion:The mtDNA copy number of embryos at different stages has an important effect on embryo development potential，and the higher the mtDNA copy number，the better the embryo quality.