Fig. 1: Epidermal deletion of SPT6 delays the hair cycle and induces hyperplasia and hyperkeratosis in the epidermis.

A Schematic representation of the strategy used to generate conditional Supt6 knockout (KO) mice using CRISPR-based genetic ablation and the Cre-loxP system. The gray triangles indicate the loxP site flanking the excised exons (black rectangles) of the Supt6 gene, enabling tissue-specific deletion upon K14-Cre recombinase expression. B Diagram illustrating the experimental timeline of tamoxifen-induced SPT6 deletion via intraperitoneal injection and the corresponding timepoints for harvesting skin samples. C Western blot analysis of SPT6 protein expression in control and Supt6-KO dorsal skin harvested on day 10 after the final tamoxifen injection. D Representative images showing the gross appearance of control and Supt6-KO mice at 0, 5, 10, 15, and 20 days after the final tamoxifen injection. E Relative body weight change (%) of control and Supt6-KO mice at 0 and 5 days after the first tamoxifen injection and at 5, 10, 15, and 20 days after the final tamoxifen injection. Body weight changes are calculated as percentages relative to the initial weight at injection day 0. F H&E staining of dorsal skin from control and Supt6-KO mice was performed at 10, 15, and 20 days after the final tamoxifen injection. The yellow arrowhead indicates epidermal hyperplasia. The green arrowheads indicate parakeratosis. The black arrowhead indicates hyperkeratosis. The scale bar represents 100 μm for H&E staining. G Quantification of the epidermal thickness of control and Supt6-KO mice was performed on days 10, 15, and 20 after the final tamoxifen injection. The mean values are shown with error bars representing the standard deviation (SD). Statistical significance is indicated as follows: **p < 0.01, ***p < 0.001, and ****p < 0.0001. n ≥ 6 per group (t-test)