Fig. 2.

Expression of nestin by pancreatic endocrine cells of Gcgr^−/− embryos at e-15. A: Photomicrograph of a section of pancreas of an e-15 Gcgr^−/− embryo immunostained for nestin (green) and insulin (red) documents the presence of a large number of nestin⁺ insulin⁺ cells (yellow). Also note that many exocrine cells are nestin positive. Scale bar = 40 μm. B: Photomicrograph of a section of pancreas of an e-15 Gcgr^−/− embryo immunostained for nestin (green) and glucagon (red) demonstrates the presence of nestin⁺glucagon⁺ cells (yellow). Scale bar = 50 μm. C: Pancreas of e-15 Gcgr^−/− embryos immunostained for insulin (red) using a guinea pig anti-insulin sera and a secondary anti-guinea pig IgG to visualize the pancreas and a green fluorescent goat anti-mouse IgG (incubation with antibodies to nestin was omitted). This picture documents the absence of immunopositive nestin cells. Scale bar = 40 μm. D: Photomicrograph of a section of pancreas of an e-15 Gcgr^+/+ embryo immunostained for insulin (red) and nestin (green) demonstrates the absence of immunopositive double-labeled cells in control mice. Similar results were obtained with e-15 PC2^+/+. Scale bar= 40 μm.