Fig. 2. Pancreatic hypoplasia and absence of islet cells in Fgf10–/–embryos. (A) Gastrointestinal tract from an E17.5 wild-type embryo. (B) Gross appearance of pancreatic region dissected from an E17.5 wild-type embryo and (C) a schematic representation illustrating the pancreas. The pancreatic tissue at this stage is localised near the spleen, which derived from the dorsal bud (green), and along the duodenum, which derived from the ventral bud (blue). (D) Haematoxylin and Eosin staining of the pancreas tissue from an E17.5 wild-type embryo showing the presence of acini exocrine tissue and heavily nucleated clusters of islet cells. (E) The islet clusters express insulin (green) and glucagon (red). (F) Exocrine tissue expresses carboxypeptidaseA (green). (G) The gastrointestinal tract from E17.5 Fgf10–/– embryos were overtly similar to that of wild-type littermates except for a smaller stomach. (H) The pancreatic tissue in the mutant Fgf10 embryos was drastically reduced (I) although present in both the splenic (green) and duodenal (blue) locations. (J) Haematoxylin and Eosin staining shows the presence of acinar tissue but no islet clusters are evident. (K) Scattered insulin (green) and glucagon-expressing (red) cells are present. Co-expression of insulin and glucagon indicates that these endocrine cells are immature (arrow). (L) The acini from the mutant Fgf10 embryo stained for the exocrine marker, carboxypeptidaseA. CA, carboxypeptidaseA; ins, insulin; glu, glucagon; st, stomach; sp, spleen.
