Figure 3
The analyses of the differentiation marker expression and cell proliferation in the URS/perineum of the β-catenin LOF and GOF mutants. Sagittal sections of the wild-type (a and d), β-catenin LOF (b and e) and β-catenin GOF (c and f) embryos. The expression of keratin 1 (a–c) and filaggrin (d–f) was assessed. Both markers were positive in perineal epithelia of wild-type embryos (red arrowheads) and in URS epithelia of β-catenin LOF embryos (blue arrowheads). The tissues surrounded by blue squares indicate the URS region (c and f). Cell proliferation was assessed using a BrdU incorporation assay (g–k). Sagittal sections of the wild-type (g), β-catenin LOF (h) and β-catenin GOF embryos (i) at E11.5. The red squares of the lower magnification pictures indicate magnified areas of (g–k). In the β-catenin LOF mutants, the cell proliferation of the URS mesenchyme was decreased at E11.5 (h). The cell proliferation in URS epithelia was increased in the β-catenin GOF mutants at E11.5 (i). Sagittal sections of the wild-type and β-catenin GOF mutants at E13.5 (j and k). The cell proliferation in the mesenchyme of the URS in the β-catenin GOF mutants was decreased (k). c, cloaca; gt, genital tubercle; r, rectum; u, urethra; urs, urorectal septum
