Fig. 1.
Partial inactivation of Shh in the developing palate in K14-Cre;Shhc/n mutant mice. (A,B) Frontal sections of E17.5 K14-Cre;Shhc/+ (A) and K14-Cre;Shhc/n (B) mutant mouse heads showing cleft palate in the K14-Cre;Shhc/n mutant. Arrowheads point to palatal shelves, and the asterisk in B marks the cleft between the bilateral palatal shelves in the mutant. (C,D) At E13.5, the percentage of BrdU-labeled cells are reduced in the palatal epithelium and mesenchyme in some K14-Cre;Shhc/n mutant embryos (D) in comparison with K14-Cre;Shhc/+ littermates (C). White arrows point to the first molar tooth buds in which cell proliferation is also reduced in the K14-Cre;Shhc/n mutant embryo in comparison with K14-Cre;Shhc/+ littermate. (E,F) Ptch1 mRNA expression is reduced in the oral epithelium and palatal mesenchyme in K14-Cre;Shhc/n mutant embryos (F) in comparison with K14-Cre;Shhc/+ littermates (E). (G,H) Gli1 mRNA expression was also downregulated in the oral epithelium and palatal mesenchyme in the K14-Cre;Shhc/n mutant embryos (H) in comparison with K14-Cre;Shhc/+ littermates (G) at E13.5. BrdU staining and mRNA signals were detected in blue. Black arrows in E-H point to the maxillary molar tooth buds. oc, mandibular ossification center; p, palatal shelf; t, tongue.