FIG. 8.

Establishment of a hierarchical role for Prep1 within the TALE protein network in embryogenesis. Prep1 is required for normal hematopoiesis, angiogenesis, and oculogenesis, as illustrated. The scheme depicts the upstream role of Prep1 as it controls Pbx and Meis TALE class homeoproteins and their target genes. Such genes become “effectors” within specific developmental processes: cMyb for erythropoiesis and Pax6 for eye development. Black arrows indicate direct control; red arrows indicate hierarchical control, whose direct or indirect nature remains to be established.