Fig. 4. Activated Wnt/ß-catenin signaling in renal vesicle progenitor cells blocks the mesenchymal-to-epithelial transition in mice. (A-H) Analysis of epithelial formation by induced renal vesicle progenitors. (A,B) DBA-negative and (C,D) E-cadherin-positive cells represent epithelial tubules originated from renal vesicles. (E,F) ß-galactosidase (cyan) labels Six2TGC-expressing cells and their descendants. In wild-type embryos (G), most cells in this population express ß-galactosidase. However, in GOF mutants of ß-catenin (H), E-cadherin expression does not overlap with ß-galactosidase expression, indicating that Six2TGC-mediated activation of Wnt/ß-catenin pathway blocks epithelialization. Yellow arrowheads indicate E-cadherin-negative clusters of cells that originate from the Six2TGC-expressing cell population. White arrowheads indicate epithelial structures in adrenal gland.