哺乳动物体内、外生产胚胎的表观遗传差异研究进展

摘要

体外胚胎生产作为一项高效的辅助生殖技术, 对优质种质资源的保存利用及遗传改良具有重要意义.但与体内生产胚胎相比, 体外生产胚胎在培养过程中出现生长发育缓慢、卵裂率低、凋亡比例增加等问题, 移植后伴随着胎盘肥大、孕期延长等问题, 还可能出现早产、出生体重降低、巨胎综合征 (LOS) 等, 这与基因表达异常和表观遗传修饰异常有重要关系.文章简单回顾了近年来表观修饰学在体内、外生产胚胎的研究进展, 主要介绍了印记基因的表观修饰、DNA甲基化及组蛋白乙酰化在哺乳动物体内、外生产胚胎之间的差异, 简述了微阵列技术在体内、外生产胚胎之间的应用, 以期找到导致体内、外胚胎质量差异的关键印记基因及其作用途径, 探讨体外生产胚胎质量低于体内胚胎的原因, 进而改善体外胚胎生产体系.%As an efficient assisted reproductive technology, in vitro embryo production is of great significance to the conservation and effective utilization of germplasm resources and genetic improvement.However, compared with embryos produced in vivo, the embryos produced in vitro develop slowly, the cleavage rate is low and the rate of apoptosis increases in the process of culture, which are accompanied by placental hypertrophy and prolonged pregnancy after transplantation.Preterm delivery, low birth weight, and macrosomia syndrome (LOS) occur after birth which are closely related to abnormal gene expression and epigenetic modification.The progress of epigenetic modification in the production of embryos in vivo and in vitro was briefly reviewed in this paper.The differences of epigenetic modification of imprinted genes, DNA methylation and histone acetylation between mammalian embryos in vivo and in vitro were introduced.The application of microarray technique in the production of embryos in vitro and in vivo was briefly described in order to obtain the key imprinted genes that lead to the difference of embryo quality betweenin vivoand in vitro, and explored the reasons why the quality of embryos produced in vitro was lower than that of in vivo, and then improved the in vitro embryo production system.