Molecular mechanism of natural pluripotency establishment in the early mouse embryo based on single-cell gene expression profile

了解在体内建立自然多能性的分子机制对于干细胞生物学在再生医学中的有效应用至关重要。这个项目的主要目的是了解小鼠胚泡内多能细胞团形成的分子程序，这也将阐明胚胎干细胞的分子特性。本项目的重点是将单细胞基因表达谱应用于小鼠着床前胚胎，以全面表征导致多能性谱系分离的分子特征。在过去的两年里，我们已经成功地建立了方法学，并在细胞内质量细胞内表征了分子特征。这导致我们：1)确定了内细胞团中两个不同种群的分子特征，即上胚层和原始内胚层；2)确定了谱系分离的最早可能的标记，从而确定了潜在的关键角色；3)表征了在早期发育阶段突出的随机基因表达。在这项建议中，我们将应用同样成功的策略来描述内细胞团和滋养外胚层细胞系之间的分离，这种分离可能发生在发育的早期阶段，即桑椹胚。总之，这将允许全面表征关键分子和导致体内基态幼稚多能性形成的潜在机制。

Understanding of the molecular mechanism leading to establishment of natural pluripotency in vivo is crucial for the efficient application of stem cell biology to regenerative medicine. The principal aim of this project is to understand the molecular program underlying formation of the pluripotent inner cell mass in the mouse blastocyst, which will also elucidate molecular properties of embryonic stem cells. This project focuses on applying single-cell gene expression profiling to the mouse pre-implantation embryo, in order to comprehensively characterize molecular signature leading to the pluripotent lineage segregation. In the last two years, we have successfully established the methodologies and characterized molecular signatures within the inner cell mass cells. This led us to i) identify the molecular signature characteristic to two distinct populations in the inner cell mass, epiblast and primitive endoderm; ii) identify the earliest possible markers, thus potential key players, for the lineage segregation; iii) characterize stochastic gene expression prominent in the early developmental stages. In this proposal, we will apply the same successful strategy to characterize the segregation between the inner cell mass and trophectoderm cell lineages, likely taking place in the earlier developmental stage, morula. Altogether this will allow comprehensive characterization of key molecules and the underlying mechanism leading to the formation of ground state naive pluripotency in vivo.