DNMT家族基因在小鼠胚胎发育过程中的功能机制研究

DNA甲基转移酶（DNMT1/3A/3B）和甲基胞嘧啶双加氧酶（TET1/2/3）动态调控DNA甲基化对哺乳动物胚胎发育至关重要。单个DNMTs蛋白在胚胎发育中的功能已有研究；然而，由于缺乏有效产生DNMT-null胚胎的手段，DNA甲基化对于胚胎发育的具体分子机制并不清楚。前期我们建立了基于单碱基编辑器在受精卵中多基因同时敲除的Multi-Stop系统。本项目将致力于解决如下三个科学问题：1）获取DNMT-null的胚胎，探讨DNA甲基化对胚胎发育的影响；2）获取DNMT和TET家族基因不同组合敲除的胚胎，探讨DNA甲基化的动态变化对胚胎发育的影响；3）利用WGBS等高通量手段解析不同DNMT敲除对DNA甲基化动态变化进而影响胚胎发育的分子机制。我们的研究将揭示DNMT和TET家族蛋白对于胚胎发育作用的关系，深入解析DNMT对于胚胎发育作用的分子机制，加深对生命起始的认识。

Dynamic regulation of DNA methylation by DNA methyltransferases (DNMT1/3A/3B) and methyl-cytosine dioxygenases (TET1/2/3) is critical for mammalian embryonic development. The function of individual DNMTs has been investigated through conventional knockout strategies; however, the developmental effects of DNA methylation remain unclear partially due to the lack of effective tools to generate DNMT-null embryos. Our unpublished data established an easy Multi-Stop system to simultaneously efficiently inactivate endogenous genes in one step. In this project, we aim to address three scientific questions by the following studies. 1) Try to get DNMT-null embryos and analyze embryonic characteristic in different developmental stages. 2) To explore functional counterbalance among DNMT and TET family genes on embryonic development through constructing different mutant embryos. 3) To uncover the molecular characteristics and mechanism of dynamic changes of DNA methylation in DNMT mutant embryos through WGBS. Our research will elucidate the relationship between DNMT and TET family genes on embryonic development and lead to deeper understanding of the initiation of life through unveiling molecular mechanism of DNMT to embryonic development.