多能干细胞主要存在两种多能状态，一种为原始态，细胞能够实现生殖系嵌合；另一种为激发态，细胞很难形成动物嵌合体。目前建立猪原始态多能干细胞系仍然存在困难，但是获得猪激发态多能干细胞则相对容易。弄清调控猪干细胞多能状态和启动胚层分化的分子机制这一科学问题，有助于猪原始态多能干细胞的建系及其临床应用。我们前期研究发现，猪源多能转录调控因子Nanog和Esrrb等与影响胚层分化的Otx2等因子存在剂量效应的互作关系。本项目拟在分子水平解析细胞状态特异调控因子Otx2的分子调控网络，研究Otx2对细胞状态特异性增强子的作用，及其引导转录因子与增强子结合，对下游基因转录调控的作用机制；拟在细胞水平确定Otx2作为负调控开关在猪干细胞原始态多能性维持和启动干细胞胚层分化过程中的关键调控作用，优化培养猪多能干细胞的培养体系和建系条件。

The pluripotent stem cells (PSCs) have two pluripotency states; one is naïve state that cells retain the potantial to form chimeric animals with germline transmission, and the other one is primed state that cells do not have the potantial to form chimeric animals. Currently, to establish porcine naïve PSC line remains to be difficult, however, to establish a primed state of porcine PSC line is relatively easier. To answer the scientific questions of maintaining porcine stem cell pluripotent states and exiting the pluripotency to promote the lineage differentiation will be conducive to the creation of porcine naïve PSCs and clinical applications. Our previous studies showed that porcine transcription factors Nanog and Esrrb interact with differentiation regulators Otx2 and Mettl3 with dose-dependent manner. In this project, our goals are (A) to investigate the regulation network of cell state-specific regulator Otx2 and to reavel the function of Otx2 to interact with cell state-specific enhancers and leading transcription factors to binding to enhancers, then to promote the downstream gene ivation; (B) to comfirm Otx2 as the negative genetic switch to regulate the naïve state of porcine PSCs and flip pluripotent stem cells to the lineage differentiation. This study will facilitate to optimize the culture conditions for creating porcine naïve PSCs.