Fig. 2. The pattern of Phox2b expression in embryonic pancreas and gut. (A-D) Mouse embryos harvested at E12.5 were stained by immunohistochemistry with peroxidase (A) for Phox2b (brown) or by immunofluorescence (B-D) for Phox2b (FITC, green in B; Cy3, red in C), Pdx1 (Cy3, red in B) and Isl1 (FITC, green in C,D). Dashed line outlines the pancreatic epithelium. Arrows indicate representative nuclei with Phox2b staining. Scale bars: 50 µm. p, pancreas; s, stomach; i, intestine.