A transcriptional roadmap for 2C-like-to-pluripotent state transition.

In mouse embryonic stem cell (ESC), a small cell population displays totipotent features by expressing a set of genes that are transiently active in 2-cell-stage embryos. These 2-cell-like (2C-like) cells spontaneously transit back into the pluripotent state. We previously dissected the transcriptional dynamics of the transition from pluripotency to the totipotent 2C-like state and identified factors that modulate the process. However, how 2C-like cells transit back into the pluripotent state remains largely unknown. In this study, we analyzed the transcriptional dynamics from the 2C-like state to pluripotent ESCs and identified an intermediate state. The intermediate state characterized by two-wave step up-regulation of pluripotent genes is different from the one observed during the 2C-like entry transition. Nonsense-mediated Dux mRNA decay plays an important role in the 2C-like state exit. Thus, our study not only provides a transcriptional roadmap for 2C-like-to-pluripotent state transition but also reveals a key molecular event driving the transition.