Fig. 4. Impaired proliferation in ß-catenin knockout pancreata. (A-E') E11.5 wild-type (A-E) or PBKO (A'-E') dorsal pancreata were analyzed by immunohistochemistry or in situ hybridization. Anti-BrdU staining (brown, A,A') labels proliferating cells; pregnant females were injected 1 hour prior to harvest (50 µg/kg). PBKO pancreata show a moderate but significant decrease in proliferation (35.4% BrdU⁺) compared with wild type (44.5% BrdU⁺). In situ hybridization (purple) reveals little or no change in expression of the potential Wnt/ß-catenin target genes cyclin D1 (B,B') and Id2 (C,C') between wild type and PBKO, whereas that of Myc (D,D') is strongly downregulated in PBKO. Expression of the Notch target gene Hes1 (E,E') is similar in the two genotypes. Red dashed lines outline pancreatic epithelia.