Fig. 5.

LacZ expression with X-Gal staining in sagittal tongue (or swelling) sections in P0-Cre/R26R mouse from E11.5 through P10. Tongue tip is toward to the right. In the epithelium, labeled cells are singly scattered at E11.5 and E12.5 (arrowheads), clustered within papillae (arrows) and between papillae at E13.5–E16.5. At E18.5-P10, labeled cells are seen in clusters in tongue epithelium and within early taste buds (open arrowheads). In tongue mesenchyme, distribution of labeled cells is overall similar to Wnt1-Cre reporter, i.e., broadly distributed throughout the tongue at E11.5–E13.5, then restricted in the mesenchyme under epithelium, and densely located in the mesenchymal core of taste papillae. Dotted lines demarcate the border between epithelium and mesenchyme. Open arrowheads point to early taste buds with labeled cells. Scale bars: 25 μm.