Cell cycle heterogeneity directs spontaneous 2C state entry and exit in mouse embryonic stem cells

• Published in: Stem cell reports 2021-11, Vol.16 (11), p.2659-2673
• Main Authors: Zhu, Yuqing, Cheng, Chen, Chen, Lang, Zhang, Li, Pan, Hongru, Hou, Linxiao, Sun, Zhen, Zhang, Ling, Fu, Xudong, Chan, Kuan Yoow, Zhang, Jin
• Format: Article
• Language: English
• Subjects: 2C-like cells; Animals; Cell Cycle - genetics; Cell Differentiation - genetics; Cell Division - genetics; Cell Line; Cell Nucleolus - metabolism; G1 Phase - genetics; G2 Phase - genetics; Gene Expression Profiling - methods; Heterochromatin - genetics; Heterochromatin - metabolism; Mice; Mouse Embryonic Stem Cells - metabolism; nucleolus; peri-nucleolar heterochromatin; Pluripotent Stem Cells - metabolism; RNA-Seq - methods; Single-Cell Analysis - methods; single-cell RNA-seq
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2021.09.003

Mouse embryonic stem cells (ESCs) show cell-to-cell heterogeneity. A small number of two-cell-like cells (2CLCs) marked by endogenous retrovirus activation emerge spontaneously. The 2CLCs are unstable and they are prone to transiting back to the pluripotent state without extrinsic stimulus. To understand how this bidirectional transition takes place, we performed single-cell RNA sequencing on isolated 2CLCs that underwent 2C-like state exit and re-entry, and revealed a step-by-step transitional process between 2C-like and pluripotent states. Mechanistically, we found that cell cycle played an important role in mediating these transitions by regulating assembly of the nucleolus and peri-nucleolar heterochromatin to influence 2C gene Dux expression. Collectively, our findings provide a roadmap of the 2C-like state entry and exit in ESCs and also a causal role of the cell cycle in promoting these transitions. •The entry to and exit from the 2C-like state showed a step-by-step roadmap•Cell cycle participates in mediating dynamic transitions between ESCs and 2CLCs•G1/S phase arrest facilitates the Dux locus escape from heterochromatin•Nucleolus-heterochromatin remodeling is involved in 2C activation In this article, Jin Zhang and colleagues show that cell-cycle variations distinguish 2CLCs, ESCs, and the intermediate states using single-cell RNA-seq. They found that cell-cycle-associated remodeling of nucleoli and peri-nucleolar heterochromatin was involved in the regulation of the 2C program. They provide novel advances in the fundamental field of 2C activation and stem cell fate decision.