Figure 6.

Sox9 ablation leads to an increase of GFP⁺/GFAP⁺ cells in the interfollicular area

(A) Quantification of DCT^neg/Nestin⁺/GFP⁺ and DCT⁺/Nestin⁺/GFP⁺ cells in Nestin⁺/GFP ⁺ cells in the bulge of Sox9KO mice and Ctrl mice 7 dpi; n = 4 mice per group; 5–12 HF per mice; data are presented as mean ± SEM.

(B) Quantification of the mean cell number of DCT^neg/Nestin⁺/GFP⁺ cells in the bulge in Sox9KO mice and Ctrl mice 7 dpi; n = 4 mice per group; 5–11 HF per mice; data are presented as mean ± SEM.

(C) Schematic demonstration of the experimental mouse model used to specifically ablate Sox9 in Nestin⁺ stem cells in the hair follicle of adult mice in vivo; adult Nestin-CreER^T2;GFP mice (Ctrl mice) with floxed alleles of Sox9 (Sox9KO mice) were intraperitoneally injected with Tamoxifen every 12 h for 5 consecutive days starting at P56 and killed 28 dpi.

(D) Immunohistochemical staining of GFP (green) in the IF of tail skin of Sox9KO mice and Ctrl mice 28 dpi; schematic drawing demonstrates the localisation of the region of interest; dashed line marks the hair follicle; E = Epidermis, IF = Interfollicular area, B = Bulge, SG = Sebaceous gland; yellow arrows point toward GFP⁺ cells; DAPI is depicted in blue (scale bar = 50 μm).

(E) Quantification of the mean cell number of GFP⁺ cells per IF in Sox9KO mice and Ctrl mice 28 dpi; n = 4 mice per group; 4 IF per mice; data are presented as mean ± SEM.

(F) Immunohistochemical staining of GFP (green) and GFAP (red) in the IF area of tail skin of Sox9KO mice and Ctrl mice 28 dpi; E = Epidermis, IF = Interfollicular area; yellow arrows point toward GFAP⁺/GFP⁺ cells; yellow arrowheads point toward GFAP^neg/GFP⁺ cells; Magnification shows GFAP⁺/GFP⁺ cells (F′); DAPI is depicted in blue (scale bar = 50 μm).

(G) Quantification of the mean cell number of GFAP⁺/GFP⁺ cells per IF in Sox9KO mice and Ctrl mice 28 dpi; n = 4 mice per group; 4 IF per mice; data are presented as mean ± SEM. (A, B, E, H) students two-sided t-test was applied to determine statistical significance (∗: p < 0.05, ∗∗: p < 0.01).