Poised enhancers (PEs) in embryonic stem cells have accessible chromatin, are bound by repressive Polycomb Group proteins, and interact with their targets prior to activation. However, whether this is recapitulated in vivo is unknown. Here the authors show PEs display these features in mouse embryos, are prevalent across vertebrates, and are required for developmental gene expression.
- Giuliano Crispatzu
- Rizwan Rehimi
- Alvaro Rada-Iglesias