Wnt/β-catenin signaling is increased in the <i>Fuz</i> null mice.

<p>Immunofluorescence on sagittal sections of E14.5 embryos. <b>A</b>) β-catenin expression was increased in the oral epithelium and mesenchyme in mutant (<i>Fuz</i>^−/−) embryos. The bottom panels are the <i>Fuz^−/−</i> embryos. <b>B</b>) β-catenin expression was also increased in the <i>Fuz</i> null Meckel's cartilage (bottom panel), compared to the heterozygote (<i>Fuz</i>^+/−, top panel) samples. <b>C</b>) Lef-1 expression in the dental epithelium, oral and dental mesenchyme at E14.5. Lef-1 expression increased in the <i>Fuz</i> null oral mesenchyme (bottom panel). <b>D</b>) These are higher magnification of the boxed areas in C. Lef-1 expression was expanded in the <i>Fuz^−/−</i> mice oral mesenchyme. <b>E</b>) The expression of <i>Tcf4</i> (<i>Tcf7l2</i>) was increased in <i>Fuz</i> mutant Meckel's cartilage (bottom panels) at E14.5 compared with wild type samples (top panels). <b>F</b>) Real-time PCR with mRNA from dissected E14.5 Meckel's cartilage and surrounding mesenchyme. Canonical Wnt target gene expression was increased whereas non-canonical Wnt pathway gene expression was decreased. β-actin served as the reference gene. Experiments were repeated three to five times each from multiple samples. <b>G</b>) Topflash reporter activity was repressed by co-transfection of <i>Fuz</i> in HEK 293FT and CHO cells. The activities are shown as mean fold activation compared to reporter activation co-transfected with pcDNA3.1 empty vector and normalized to SV-40 β-galactosidase activity. Error bars indicate S.E. *: <i>p</i>-values<0.05; **: <i>p</i>-values<0.01.