Fig. 1. Hhip (Hip1 in figure) is expressed at low levels in developing and mature pancreas. Staining for ß-galactosidase activity in heterozygous Hhip mice that carry the lacZ gene under control of the endogenous Hhip promoter reveals that high level expression within the fore-midgut region is confined to stomach and duodenum, but is excluded from pancreatic tissue (A,C,E). Staining for ß-galactosidase activity in Ptch-lacZ knock-in embryos (B,D; Ptch1 in figure). Low level of ß-galactosidase activity is observed in adult islets of Hhip-lacZ knock-in mice (F). RT-PCR analysis of Hhip gene expression of pancreatic tissue at different stages reveals low-level expression (G). Top lane, Hhip expression; bottom lane, mouse ribosomal protein L19 expression as an internal control. d, duodenum; dp, dorsal pancreas; s, stomach; sp, spleen; vp, ventral pancreas.