Fig. 4. Expression of Wnt/ß-catenin target genes in the mutant epiblast. Immunohistochemical analysis of sections from wild-type (A) and mutant (B) E5.5 embryos revealed an enhanced cytoplasmic localization of ß-catenin in cells of the mutant epiblast. No difference between wild-type and mutant epiblast was observed for Oct4 (C,D), while some cells in the mutant epiblast expressed T-Brachyury protein (E,F). In situ hybridization analysis of the expression of Snai1 in wild-type (G) and mutant (H) embryos revealed expression in some cells of the mutant epiblast. All embryos are oriented with the embryonic part to the right. Scale bar: 100 µm.