Fig. 4. Fewer epithelial structures in DAPT-treated metanephroi. Hematoxylin and Eosin-stained sections of metanephroi cultured for 5 days in DMSO (A) or DAPT (E). Fewer renal tubular epithelia and more interstitial cells are seen in the DAPT-treated metanephroi. Note dilated collecting ducts in the DAPT-treated metanephroi (asterisks in E and G). (B-D,F-H) Expression of several epithelial cell markers. (B,F) Ncam (green) and Pax2 (red). Pax2 only: ductal cells (arrowheads). Pax2 + Ncam: condensing mesenchyme (orange). Ncam only: epithelial cells (B, arrows) or uninduced mesenchyme (asterisks). (C,D,G,H) Expression of E-cadherin (brown), an epithelial marker present in ducts and enriched in distal tubules, on Hematoxylin counterstained (purple) slides. Insets in C and G: detection of cytokeratin 8 (red), a ductal marker, in sections adjacent to C and G. These images were overlaid using Canvas (Deneba software) on C and G to create images D and H. E-cadherin was highly expressed in both collecting duct and nephron epithelia. Fewer non-ductal epithelia (i.e. cytokeratin 8 negative) developed in DAPT-treated metanephroi (circled, H).