胚胎自我修复

Self-correction in human embryos

人类早期胚胎存在较高比例的染色体异常现象。近年来，随着检测技术的不断进步，人们对胚胎染色体异常的认识也在逐步加深。2005年先后有报道，染色体异常的早期胚胎可发生部分或全部胚胎细胞的自我修复，但自我修复率及其相关机制尚未明确。以下就这方面的研究进展进行综述。

Reanalysis of aneuploid embryos diagnosed by preimplantation genetic screening（PGS） using fluorescence in situ hybridization（FISH）showed that part or all cells in some human cleavage-stage embryos may undergo self-correction during preimplantation development. Putative embryo self-correction mechanisms include embryonic mosaicism, preferential segregation of chromosomal abnormalities to the trophectoderm and extrusion or duplication of aneuploid chromosomes resulting in uniparental disomy. However,embryo self-correction has not been proved in the study using a single nucleotide polymorphism （SNP）microarray-based 24 chromosome aneuploidy screening technology. Neither preferential segregation of aneuploidy to trophectoderm nor uniparental disomy was found. Further study to improve the accuracy of karyotyping on cleavage-stage embryos is definitely needed.