Figure 2. TAp63−/− mice lose hair follicles with age.

(A) Confocal images of immunocytochemistry of a hair follicle from a young, wild-type mouse for fibronectin (green), NCAM (dark blue), p63 (red), and Hoechst 33258 (blue). Hatched line denotes the dermal papilla (DP), yellow arrowhead indicates a p63-positive dermal sheath (DS) cell, arrows show a p63-positive dermal papilla cells, and white arrowheads epidermal cells with nuclear p63. Magnification 630X. (B) RT-PCR for TAp63 mRNA in Sox2:EGFP-positive (+ve) and negative (−ve) cells from adult backskin. #1, 2 and 3 are samples from 3 different mice, and the ungated sample is total skin cells from one mouse. (C) SA-β-gal staining (blue) of hair follicles in young wild-type or TAp63−/− skin (left two panels). The arrows indicate SA-β-gal-positive dermal papillae. The right two panels, (a) and (b), are micrographs of sequential sections through the same hair follicle, 40µm apart. The arrowhead indicates an SA-β-gal-positive dermal sheath cell (DS), and the arrows a positive dermal papilla (DP). (D) Quantification of SA-β-gal positive cells in the dermal papillae (DP). n = 3 animals per group. *p<0.05. (E) H&E stained skin sections of 1, 6, and 12 month wild-type (WT) and TAp63−/− mice. Arrows denote hair follicles, and double-arrows indicate regions of TAp63−/− skin depleted of hair follicles. Magnification 100X. (F) Quantification of hair follicles per millimeter (E). N = 8 and 4 mice each for wild-type (WT) and TAp63−/− at 1 month and 12 months, respectively. *p<0.05. (G) Quantification of hair follicles in wild-type (WT) and TAp63−/− mice at 1, 6–9, and 12 months. Only patches of skin with no follicles for greater than 400µm were included. N = 4 mice of each genotype at each time point. *p<0.05.