New insights into the epitranscriptomic control of pluripotent stem cell fate

Epigenetics: chemical tags on RNA mediate stem cell fate Chemical modifications made to key gene transcripts, messenger RNAs carrying genetic information from DNA, help to govern the differentiation potential and developmental stage of stem cells in the early embryo. Yong Jun Kim of Kyung Hee University in Seoul, South Korea, and colleagues review the molecular pathways that control the identity of stem cells and highlight how these epigenetic changes during embryonic development can impact the fate of cells. The addition of methyl groups to particular parts of gene transcripts that encode for regulatory proteins seems to be an especially common mechanism for maintaining pluripotency, the ability to form any cell type in the body. Other types of modification also play a role, collectively impacting stem cell dynamics in ways that could be important for regenerative medicine. Each cell in the human body has a distinguishable fate. Pluripotent stem cells are challenged with a myriad of lineage differentiation options. Defects are more likely to be fatal to stem cells than to somatic cells due to the broad impact of the former on early development. Hence, a detailed understanding of the mechanisms that determine the fate of stem cells is needed. The mechanisms by which human pluripotent stem cells, although not fully equipped with complex chromatin structures or epigenetic regulatory mechanisms, accurately control gene expression and are important to the stem cell field. In this review, we examine the events driving pluripotent stem cell fate and the underlying changes in gene expression during early development. In addition, we highlight the role played by the epitranscriptome in the regulation of gene expression that is necessary for each fate-related event.