Figure 3. Co-localization of Apc with β-catenin in the lung epithelium.

(A–F) Double immunofluorescent staining of Apc with total β-catenin. (A–C) In E14.5 lung, Apc is predominantly expressed in smooth muscle cells (A), whereas membranous β-catenin is present in every cell with a higher intensity in the epithelial compartment (B). (D–F) In adult lung, Apc is predominantly expressed in the cytoplasm of a subpopulation of airway epithelial cells (D). Cytoplasmic β-catenin was observed in the Apc positive cells (E and F). Block arrows in A and D indicate Apc signal. Scale bars, 20μm for Panels A–C; 10μm for Panels D–F.

(G–L) Double immunofluorescent staining of phospho-β-catenin with β-tubulin IV (G–I) or CC10 (J–L) in adult lungs. Phospho-β-catenin (P-β-cat, red, G&I) was detected in β-tubulin IV^positive cells (H&I), but not in CC10^positive cells (K&L). Arrows in G and J indicate P-β-cat signals. Scale bar, 10μm.