Fig. 5. Endocrine development in RbpjKO, Notch1/2KO and Rbpj^+/- pancreata. (A-L) Transverse sections from E18.5 Rbpj^+/-, Notch1/2KO and RbpjKO;R26R embryos were analyzed for the expression of endocrine markers by immunohistochemistry. RbpjKO pancreas was stained by X-Gal (blue) in addition to the respective endocrine genes. l, liver. (M-O) X-gal staining of sections from Rbpj^+/-;R26R, Notch1/2KO;R26R and RbpjKO;R26R embryos at E18.5. Arrows mark the areas in insets (enlarged 2x). (P-R) Double-immunofluorescence staining of islets with anti-glucagon (red) and anti-insulin antibodies (green). (S-U) The merged images show co-expression of glucagon and insulin with β-galactosidase in islets of knockouts and control pancreata. (V) Histogram representing the number of islets±s.d. in pancreata of three embryos for the indicated genotype. Ins, insulin; Gluc, glucagon; PP, pancreatic polypeptide. Scale bar: 50 µm.