Figure 2.

Impaired differentiation of α and β cells in the pancreas of Insm1 mutant mice. Immunohistological analysis of the developing dorsal pancreas of Insm1^lacZ/+ and Insm1^lacZ/Insm1^lacZ mice at E12.5 (A–C,G–I) and E15.5 (D–F,J–L); the genotypes are indicated by +/− and −/−, respectively. The antibodies used were directed against β-galactosidase (red) and insulin (green) (A,B,D,E), and β-galactosidase (red) and glucagon (green) (G,H,J,K). (C,I) Proportions of β-galactosidase⁺ cells that express insulin (C) and glucagon (I) in the dorsal pancreas in Insm1^lacZ/+ (gray column) and in Insm1^lacZ/Insm1^lacZ (black column) mice at E12.5. (F,L) Proportions of β-galactosidase⁺ cells that express insulin (F) or glucagon (L) in the dorsal (D) and ventral (V) pancreas of Insm1^lacZ/+ and Insm1^lacZ/ Insm1^lacZ mice at E15.5. Asterisks indicate p-values of <0.01. Bar, 20 μm.