猪体细胞核移植胚胎X染色体活性变化及其调控机制探索

X染色体活性状态与胚胎发育潜力密切相关。我们的前期研究表明猪体细胞核移植（SCNT）胚胎X染色体存在过度失活（ectopic XCI），是猪SCNT胚胎发育的潜在瓶颈。据此，本研究拟探究猪SCNT胚胎X染色体活性变化及其背后的调控机制。围绕该科学问题，本项目首先将确定猪X染色体失活中心（Xic）相关因子的基因序列及其表达模式；然后利用不同来源胚胎的测序结果研究猪胚胎XCI模式以及确定其启动与建立的时间；接下来确定Xist以及其他可能调节因子在早期胚胎XCI中的作用；最后系统比较猪SCNT胚胎与体内或体外受精胚胎的X染色体活性及表观差异，并通过调控关键的表观因子来改善猪SCNT胚胎的发育效率和质量。

The active state of X chromosome is closely related to embryonic development potential. Our previous research showed that the X chromosome of the pig somatic cell nuclear transfer (SCNT) embryo is ectopic inactivated (ectopic XCI), which is the potential bottleneck for pig SCNT embryo development. Based on this, this study intends to explore the changes in the X chromosome activity of pig SCNT embryos and the underlying regulatory mechanisms. Focusing on this scientific issue, this project will first determine the sequences and expression patterns of genes related to X chromosome inactivation centers (Xic); then use the sequencing results of embryos from different sources to study the XCI model of pig embryos and determine the time of their initiation and establishment; then determine Xist and other potential regulatory factors in XCI; finally, systematically compare the X chromosome activity and apparent differences between pig SCNT embryos and in vivo or in vitro fertilized embryos, and improve the development efficiency and quality of pig SCNT embryos by regulating key epigenetic factors.