Fig. 6. Elevated Shh and Foxa2 but reduced Nkx3.1 expression in Foxa1^–/– epithelium. (A) Shh expression in 4-week-old rescued Foxa1^–/– VP epithelium, with strong and focused activity evident in the epithelial buds (B). (C) Ptch1 is detected in the same null epithelial buds. (D,E) Triple-immunofluorescence of ß-catenin (red), p63 (green) and DAPI (blue) on rescued Foxa1^–/– and Foxa1^+/+ prostates. (F-I) Foxa1^–/– epithelium is negatively or faintly stained for nuclear Nkx3.1 (F,H). Arrowheads indicate the same epithelial buds illustrated in B. Foxa1^+/+ luminal epithelium show strong nuclear Nkx3.1 immunoreactivity (G,I). (J-L) Foxa2 is expressed in Foxa1^–/– epithelium (J,K), but not in Foxa1^+/+ epithelium (L).