Figure 4.

Periderm of Specc1l^cGT/ΔC510 embryos show changes in F-actin and adherens junction markers consistent with abnormal adhesion. (A–C) Immunostaining for SPECC1L (red) and ΔNp63 (green; basal epithelial marker) on coronal sections between E13.5 and E14.5. SPECC1L expression is present in the periderm and basal layers of the epithelium (A′; arrow), as well as the underlying mesenchyme. Scale bar for A–C is 2 mm and for A′–C′ is 50 μm. (D–K) Coronal sections of E13.5 WT and Specc1l^cGT/ΔC510 palatal shelve epithelia co-immunostained for cell junction marker β-catenin (D and H) and basal epithelium marker ΔNp63 (E and I). Both WT and mutant sections contain flattened, ΔNp63-negative periderm cells (G and K; arrows). However, the mutant sections have abnormal apical β-catenin staining on some periderm cells (G vs. K; arrows). (L–S) Sections stained with phalloidin (L and P) show increased F-actin staining in the mutants compared to controls (O vs. S). Scale bars are 10 μm. p, palatal shelf; mx, maxillary process; mn, mandibular process; t, tongue; ns, nasal septum.