Figure 1.

Recombination in adult Nestin-CreER^T2 transgenic mice targets Sox9-expressing hair follicle stem cells

(A) Schematic drawing of an adult hair follicle (HF) showing the localisation of Nestin-expressing cells (Nestin⁺) (green) and melanocytic cells in various differentiation stages; ORS = outer root sheath.

(B) Schematic drawing depicting the applied tamoxifen protocol to track Nestin⁺ cells and their progeny in vivo; Nestin-CreER^T2; GFP mice (Ctrl mice) were intraperitoneally injected with tamoxifen every 12 h for 5 consecutive days starting at P56 and were killed 7 days post-injection (dpi).

(C) Representative immunohistochemical staining for GFP (green) and Sox9 (red) in tail skin of tamoxifen-treated Ctrl mice 7 dpi. Yellow arrows point toward recombined GFP⁺/Sox9⁺ cells in the bulge; dashed line marks the hair follicle; E = Epidermis, HF = Hair follicle, SG = Sebaceous gland, IF = Interfollicular area, B = Bulge, ORS = Outer root sheath, Bu = Bulb; DAPI is depicted in blue (scale bar = 50 μm).

(D) Immunohistochemical staining of GFP (green), Sox9 (red) and Nestin (white) in the hair follicle of Ctrl mice; Magnifications show signals in the bulge (D′); Yellow arrows point toward Sox9⁺/Nestin⁺/GFP⁺ cells; dashed line marks the hair follicle; HF = Hair follicle, SG = Sebaceous gland, B = Bulge; DAPI is depicted in blue (scale bar = 20 μm).

(E) The graphs show the quantification of Sox9⁺/GFP⁺ over total GFP⁺ cells per HF in tamoxifen-treated Ctrl mice 7 dpi; n = 4 mice, 4–10 HF per mice.

(F) Quantification of Sox9⁺/Nestin⁺/GFP⁺ over total Nestin⁺/GFP⁺ cells per HF in tamoxifen-treated Ctrl mice 7 dpi; n = 4 mice, 4–10 HF per mice. Data are presented as mean ± SEM.