Fig. 2

Analysis of glucose tolerance, insulin secretion, and Insm2 homologous or regulatory genes. a, b Fasting glucose levels are elevated at 24 weeks Insm2^−/− male and at 16 and 24 weeks old Insm2^−/− female mice. Values are presented in mean ± SEM from eight animals per group in three separate experiments (**P < 0.01; ***P < 0.001). c, d Glucose tolerance tests in male and female Insm2^+/+ and Insm2^−/− mice. After overnight fasting, d-glucose (2 g/kg body weight) was injected intraperitoneally, and blood glucose levels were measured at different times as indicated. Values are presented in mean ± SEM from 14 mice per group in three separate experiments (**P < 0.01; ***P < 0.001). e, f Blood insulin and C-peptide levels in response to intraperitoneal glucose in male and female Insm2^−/− mice aged 16–24 weeks were measured and compared to Insm2^+/+ mice at 15 min. Blood samples were drawn from the tail vein using heparinized capillary tubes before and after glucose injection