Fig. 1. Expression of Shox2 in the developing palate. (A-C) Shox2 expression (arrows) is detected by whole-mount (A) and section (B,C) in situ hybridization in the anterior (A,B) but not the posterior portion of palatal shelves at E11.5. The expression is restricted in the palatal mesenchyme (B). (D-F) At E12.5, Shox2 expression (arrows) domain expands but is still restricted in the anterior palatal mesenchyme, as detected by whole-mount (D) and section (E) in situ hybridization. (G-I) Shox2 expression (arrows) is still restricted in the anterior (G,H) but not in the posterior region (I) at E13.5. The expression at this stage expands to the palatal epithelium (H). (J-L) At E14.5, Shox2 expression exhibits a pattern of alternative stripes in the anterior half of the palate (J). The expression is detected in both the palatal mesenchyme and epithelium (K). (M) SHOX2 is also detected in the anterior palate of human embryo of 42 days post-conception (dpc), equivalent to mouse E11.5. (N) The posterior palate of human embryo of 42 dpc shows no SHOX2 expression. All sections shown were made through a coronal plane. M, the first molar; T, tongue; PS, palatal shelf. Scale bar: 200 µm.