Fig. 2

Fig. 2 Nature of the islet defect in the zebrafish mutant syu^t4. The morphology of WT (A) vs syu embryos (B) was compared. Paraffin transverse cut sections (5 μm), stained with hematoxylin and eosin. (A) WT islet (arrow). (B) The islet is selectively missing in syu embryos (arrow). (C) Carboxypeptidase A expression (arrow) in 72-hpf syu embryos embedded in paraffin, sectioned, and counterstained with Vector Green. (D–I) Whole-mount in situ hybridization analysis of Wt and syu^-/- embryos. Views are dorsal with anterior to the left, except (I), which is a lateral view. (D) Carboxypeptidase A expression in 48-hpf WT and syu^-/- embryos. (E) Expression 72 hpf of transferrin (F) Pdx-1 expression in 48-hpf WT pancreas (arrow) and duodenum (arrowhead). (G) Isl-1 expression in 48-hpf syu^-/- embryos. Arrows denote loss of expression. Foregut expression (arrowheads) is retained. (H) Loss of Beta2/NeuroD expression within the islet at 48 hpf (arrow) in syu^-/- embryos. (I) Nkx2.2 (nk2.2) expression in WT 24-hpf embryos in early gut endoderm where the pancreatic diverticulum will form (arrow).