Fig. 2.

A–F: LacZ expression with X-Gal staining in sagittal sections of Wnt1-Cre/R26R mouse tongue at E12.5, E14.5, E16.5, and P1. Tongue tip is toward to the right. Labeled cells are broadly distributed in tongue mesenchyme at E12.5 (A). Then, progressive restriction of labeled cells are observed in the mesenchyme just under lingual epithelium and the mesenchymal core of fungiform papillae (B–D, fp, arrowheads), foliate (E, short arrows), and circumvallate (F, long arrow). Black dotted lines in A–F demarcate the borders between epithelium and mesenchyme. G–I: Double labeling of β-galactosidase (green) and epithelial cell marker K5 (red) to confirm the mesenchymal location of Wnt1-Cre labeled cells and association with taste papillae. Scale bars: 25μm in A–C; 50 μm in D–I.