印记紊乱引起的胎盘发育异常是体细胞核移植技术失败的主要原因。PGC7是合子期维持和保护印记的关键母源因子。我们发现PGC7是一个天然无序蛋白，并建立了包含291个蛋白的PGC7互作蛋白网络。本项目拟以胚胎干细胞为实验材料，以维生素C处理或转染TET3作为DNA去甲基化的胁迫模型，以Dlk1-Dio3印记区作为印记调控靶标位点，从PGC7的互作蛋白网络入手，研究PGC7在印记维持和保护方面的功能机制。通过研究PGC7与UHRF1、DMAP1及HP1BP3之间的互作调控关系，揭示PGC7及其互作蛋白在Dlk1-Dio3印记区招募维持DNA甲基化酶DNMT1和调节染色质结构等方面的分子机制，阐明PGC7印记维持和保护功能的分子作用机理。同时本项目拟通过观察牛IVF胚胎与克隆胚胎中PGC7及其互作蛋白的互作调控差异，揭示克隆胚胎中影响印记维持或保护的因素，为提高体细胞克隆效率提供新的思路和方法。

Placental dysplasia caused by imprinting disorders is the main cause of failures of somatic cell nuclear transfer (SCNT). PGC7 is a critical maternal factor for zygotic imprinting maintenance and protection. Our previous work showed that PGC7 was an intrinsically disordered protein, and we have established the protein interaction networks of PGC7 which contains 291 proteins. Here we propose to investigate the molecular mechanism of PGC7-mediated imprinting maintenance through analyzing the PGC7 interacting protein network. In this study, we use embryonic stem cells as the model cell, treatment of cells with Vc or transfected with TET3 as the stress condition of DNA demethylation, and Dlk1-Dio3 imprint region as the target site of imprinting regulation. By studying the interaction regulations between PGC7 and UHRF1, DMAP1 or HP1BP3, we want to reveal the molecular mechanism of PGC7 and its interaction proteins in recruiting DNMT1 or regulating chromatin structure at Dlk1-Dio3 imprint region. At the same time, this project is intended to reveal the factors affecting the maintenance of imprinting in cloned embryos by observing the differences of PGC7 interactions between bovine IVF embryos and cloned embryos, and to provide new ideas and methods for improving the efficiency of SCNT.