Fig. 3. Comparison of molar tooth and hair follicle development between wild-type and p63 mutant embryos. (A,B) At E11, no difference could be detected between wild-type and p63^-/- tissues during the initiation of tooth development (arrows). (C-F) At E12 and E13, dental placodes and tooth buds (arrows) had formed in wild-type embryos, whereas in the mutant littermates development had arrested at the stage of thickened dental epithelium (arrows). (G,H) At E16, wild-type molars had advanced to the bell stage, whereas in p63 mutants the epithelial thickening had degenerated. (I) The first wave of hair follicles (guard; arrow) had developed to stage 3-4, the placodes of the second wave awl follicles had appeared in wild-type skin at E16.5 and the epidermis had increased in thickness. (J) p63^-/- epidermis lacked stratification and hair follicles. sr, stellate reticulum; dp, dental papilla.