Fig. 2. Lack of HNF6 results in absence of gallbladder, abnormal morphogenesis of the extrahepatic bile ducts and cholestasis. (A) In wild-type adult mice, the gallbladder is seen on the ventral side of the liver and the hepatic ducts merge with the cystic duct to form the common bile duct, which ends up in the duodenum. (B) In Hnf6^–/– adult animals, the gallbladder is absent. An enlarged structure (arrow) connects the liver to the duodenum. (C,D) Transverse sections in E10.5 embryos. The sections were stained for Pdx-1 to identify the ventral pancreatic bud (strong staining) and the duodenum (weak staining). Rostral is towards the left, caudal towards the right. (C) In wild-type embryos, the gallbladder primordium, devoid of Pdx-1 staining, is observed between the liver primordium and the ventral pancreatic bud. (D) In Hnf6^–/– embryos, the gallbladder primordium is absent. Note that the ventral pancreatic bud is also missing at E10.5, as formation of the pancreatic buds is delayed in Hnf6^–/– mice (P. J., G. G. R. and F. P. L., unpublished). (E,F) Fouchet’s staining on liver sections from Hnf6^–/– mice at P6. (E) Abnormal bile accumulation between the hepatocytes (arrowheads) is observed. (F) Large areas of bile accumulation surrounded by necrotic parenchyma are also detected. bl, bile lake; cbd, common bile duct; cd, cystic duct; d, duodenum; gb, gallbladder; hd, hepatic duct; lp, liver primordium; p, liver parenchyma; vp, ventral pancreatic bud. Scale bars: 50 µm in C,E (bar in C also applies to D); 100 µm in F.