Fig. 6. Mosaic Ras^G12V cells stimulate cell mass formation in damaged skin.

a Representative images show cell mass in Tg(krt4p: gal4; UAS:G43EGFP-TP53^R175H) larval head region with mCherry⁺Ras⁺ (Ras⁺) cells (red). Graph shows percentage of embryos with cell mass (mean ± SEM). b, c Tg(krt4p: :gal4; UAS:G43EGFP-TP53^R175H) larvae with Ras⁺ cells with control or il1b MO (b) or untreated or treated with NAC (c). Graph shows the percentage of 1.5 dpf embryos with cell mass (mean ± SEM). Each dot in graph (a–c) represents an independent experimental result. d–g Doxorubicin promotes senescence and SASP factor production in mosaic Ras⁺ cells. In d, representative images show fluorescence in situ hybridization for cdkn2a/b mRNA (magenta) in Ras⁺ cells (green) with or without doxorubicin treatment, and nucleus (blue). Arrow and arrowhead indicate cdkn2a/b⁺Ras⁺ cells weakly or strongly, respectively. Graph shows percentage of cdkn2a/b⁺Ras⁺ cells. In e–f, representative images show fluorescence in situ hybridization for il1b (e) or il11b mRNA (f) (magenta) in Ras⁺ cells (green) with or without doxorubicin treatment. Arrows indicate il1b⁺Ras⁺ or il11b⁺Ras^G12Vcells. Graph shows percentage of il1b⁺Ras⁺ or il11b⁺Ras^G12V cells (mean ± SEM). Each dot represents one larva. In g, representative images show ROS-probe, CellROX (magenta), -stained larvae with Ras⁺ cells (green) with or without doxorubicin treatment. Box plots of CellROX relative intensities in Ras⁺ cells show first and third quartile, median is represented by a line, whiskers indicate the minimum and maximum. Each dot represents one cell. h Representative images show cell mass in the head region of doxorubicin-treated larvae with GFP⁺Ras⁺ (Ras⁺) cells (green). Right graph shows percentage of embryos with cell mass (mean ± SEM). i Doxorubicin-treated larvae with Ras⁺ cells with control or tp53 MO. Graph shows percentage of 1.5 dpf embryos with cell mass (mean ± SEM). Each dot in graph (h, i) represents an independent experimental result. Note that cell mass formation was induced not only in the head but also in the trunk and tail in TP53^R175H-expressing and doxorubicin-treated skin. Scale bar: 50 (a, h) or 10 (d–g) μm. Unpaired two-tailed t-test (a–c, e–i) or Fisher’s exact test with Benjamini–Hochberg correction (d) was used. Source data are provided as a Source Data file.