Polycomb repressive complex 1 (PRC1) role in skin epithelium development [Epidermis I53A]

Polycomb repressive complexes (PRC) 1 and 2 are essential chromatin regulators of cell identity. PRC1, a dominant executer of Polycomb-mediated control, functions as multiple sub-complexes that possess catalytic-dependent H2AK119 mono-ubiquitination (H2AK119ub) and catalytic-independent activities. Here, we show that despite its well-established repressor functions, PRC1 binds to both silent and active genes. Through in vivo loss-of-function studies, we show that global PRC1 function is essential for skin development and stem cell (SC) specification. Newborn mouse epidermal cells were purified from Ring1a-/- Ring1b-/I53A mutants and control mice. RNA from the sorted cells was analyzed by RNA-seq.