Fig. 2. Severe liver hypoplasia in vHnf1^-/- embryos. (A) Direct observation of WT and vHnf1^-/- mouse embryos at E13.5 shows an essentially empty abdominal cavity in the mutants (arrows). (B) Liver dissection at E14.5 reveals the liver hypoplasia of mutant embryos. (C,D) Hematoxylin and Eosin (H&E) staining of sagittal sections of WT (C) and vHnf1^-/- (D) embryos at E13.5 show the reduced volume of mutant liver and the presence of hemorrhagic regions (arrow). At higher magnification, the strong disorganization of mutant liver tissue is evident (compare insets). (E,F) Immunostaining at E13.5 indicates the absence of E-cadherin expression in mutant liver (F), in contrast to WT (E) in which the staining reveals the epithelial organization of hepatoblasts. The insets illustrate correct E-cadherin expression in the stomach epithelium of WT (E) and of mutant (F) embryos. (G,H) TUNEL analysis at E13.5 shows a massive apoptosis of the majority of cells that compose the mutant liver (H), whereas in WT embryos few apoptotic cells are observed (G). The dashed line outlines the liver.