OCT4和CDX2两种转录因子在小鼠早期胚胎细胞中互斥性表达对于内细胞团（ICM）和滋养层（TE）分化具有重要作用，在囊胚中OCT4特异性表达于ICM，而CDX2特异性于TE表达。但在以猪为代表的其它大型哺乳动物，OCT4持续在囊胚TE中表达。据此，我们提出如下科学问题：OCT4在猪囊TE中持续表达的生物学意义和发挥功能的分子网络途径。围绕该科学问题，本研究将确认OCT4在猪囊胚TE中的精确表达模式，通过特异性调控OCT4在TE中的表达，跟踪胚胎发育表型变化，推断其对胚胎发育的生物学作用；通过TE细胞嵌合体制作和TE细胞体外培养建系探索OCT4对TE细胞的生物学作用；通过RNA-Seq测序和ChIP-Seq建立OCT4在TE细胞中发挥生物学功能的分子调控网络；筛选并验证OCT4下游候选调控基因作用关系，最终初步建立猪TE细胞中OCT4发挥功能的分子调控网络。

The exclusively expression of Oct4 and Cdx2 in mouse embryonic cells is crucial for inner cell mass （ICM） and trophectoderm（TE ）differentiation and results in Oct4 specially expressed in ICM and Cdx2 specially expressed in TE. But OCT4 keep expressing in TE in large mamalian embryos represented by pig. According to this biological phenomenon, we proposed the scientific question: what is the biological importance of OCT4 keep expressing in porcine TE cells and what is the molecular net works that OCT4 functioned through in TE. Based on the scientific question, in this study the accurate expression pattern of OCT4 in TE of porcine blastocyst will be examined; the funtion of OCT4 on embryonic development will be analyzed by the development results of TE specific OCT4 over expression or knock down embryos. The function of OCT4 on TE cells will be explored by the potential of TE chimeric development and the characteristics of TE derived stem cell lines. The molecular net works of OCT4 functioned in TE will be investicated by RNA-Seq and ChIP-Seq. OCT4 down stream candidate genes will be screened and verificated by routine way and finally OCT4 regulation net works will be constructed.