Figure 5.

Sox9 ablation leads to a reduced number of proliferating melanocytic cells accompanied by a hyperproliferation of stem cells

(A) Immunohistochemical staining of GFP (green), Ki67 (red) and Nestin (white) in Ctrl mice and Sox9KO mice 7 dpi; magnifications show signals in the bulge in Ctrl mice (A′) and Sox9KO mice (A''); dashed line marks the hair follicle; B = Bulge; DAPI is depicted in blue (scale bar = 20 μm). Yellow arrows point toward triple positive cells (Ki67⁺/Nestin⁺/GFP⁺).

(B) Quantification of the mean number of Ki67⁺/GFP⁺ cells in Sox9KO and Ctrl mice 7 dpi; n = 4 mice per group; 6–12 HF per mice; data are presented as mean ± SEM.

(C) Quantification of the mean number of Ki67⁺/Nestin⁺/GFP⁺ cells in the bulge of Sox9KO and Ctrl mice 7 dpi; n = 4 mice per group; 4–12 HF per mice; data are presented as mean ± SEM.

(D) Quantification of the mean number of Ki67⁺/DCT⁺/GFP⁺ cells per HF in Sox9KO and Ctrl mice 7 dpi; n = 4 mice per group; 6–12 HF per mice; data are presented as mean ± SEM.

(E) Immunohistochemical staining of GFP (green), Ki67 (red) and DCT (white) cells in Ctrl mice and Sox9KO mice 7 dpi; magnifications show signals in the bulb of Ctrl mice (E′) and SoxKO mice (E''); dashed line marks the hair follicle; Bu = Bulb; DAPI is depicted in blue (scale bar = 20 μm); Yellow arrows point toward Ki67⁺/DCT⁺/GFP⁺ cells; yellow arrowheads point toward Ki67^neg/DCT⁺/GFP^neg cells (C) – (D) students two-sided t-test was applied to determine statistical significance (∗: p < 0.05, ∗∗: p < 0.01).