Micro-RNAs meet epigenetics to make for better brains

Recent studies have highlighted the importance of regulatory non‐coding RNAs and epigenetics in controlling the differentiation of somatic stem cells. Two major pathways characterize these fields: micro‐RNAs (miRNAs) and DNA methylation. In this issue of EMBO Reports, Lv et al show that during mammalian corticogenesis, miR‐15b inhibits cytosine demethylation by targeting Tet3, a key methylcytosine dioxygenase. This leads to the epigenetic downregulation of cyclin D1. As a result, cell cycle and differentiation of neural progenitors are altered, promoting their switch to neurogenesis. Hence, Lv et al elegantly bring together miRNAs and DNA methylation in the cell cycle control of neural progenitors and neurogenesis.