What is the difference in the roles of Tcf1 and Tcf3 during development?
Τhere are opposing effects of Tcf3 and Tcf1 in the control of Wnt stimulation of embryonic stem cell self-renewal. In contrast to β-catenin-dependent functions described for Tcf1 the known embryonic functions for Tcf3 are consistent with β-catenin-independent repressor activity. Wnt signal stimulation reduces the level of Tcf3, and increases those of Tcf1 (also known as Tcf7) and Lef1, positive mediators of Wnt signaling.