Fig. 8
From: SCL/TAL1 cooperates with Polycomb RYBP-PRC1 to suppress alternative lineages in blood-fated cells
Model of SCL’s functions in blood lineage specification. Single mesodermal cells co-express blood (Scl), cardiac (Mesp1) and paraxial (Tbx6)-affiliated transcriptional regulators at low levels, establishing multi-lineage priming and cellular plasticity. As differentiation progresses, Scl levels increase in FLK1+PDGFRα– cells. SCL establishes a global repressive environment by activating potent transcriptional repressors (Rybp/Pcgf5/Eto2) and ensuring genome-wide, high H2AK119Ub levels. This leads to decreased Mesp1 and Tbx6 levels and repression of alternative fates. Activation of blood/endothelial gene expression programmes together with decreased plasticity allows consolidation of the blood fate and specification of the hematopoietic lineage
