Cell fate decision by a morphogen-transcription factor-chromatin modifier axis.

Cell fate decisions remain poorly understood at the molecular level. Embryogenesis provides a unique opportunity to analyze molecular details associated with cell fate decisions. Works based on model organisms have provided a conceptual framework of genes that specify cell fate control, for example, transcription factors (TFs) controlling processes from pluripotency to immunity. How TFs specify cell fate remains poorly understood. Here we report that SALL4 relies on NuRD (nucleosome-remodeling and deacetylase complex) to interpret BMP4 signal and decide cell fate in a well-controlled in vitro system. While NuRD complex cooperates with SALL4 to convert mouse embryonic fibroblasts or MEFs to pluripotency, BMP4 diverts the same process to an alternative fate, PrE (primitive endoderm). Mechanistically, BMP4 signals the dissociation of SALL4 from NuRD physically to establish a gene regulatory network for PrE. Our results provide a conceptual framework to explore the rich landscapes of cell fate choices intrinsic to development in higher organisms involving morphogen-TF-chromatin modifier pathways.