Supplementary Figure 3: EdU-BrdU pulse chase differentiation assay measures renewal rate in epidermis.

(a) and (b), Statistics (a) and representative images (b) show that short (2 hour) pulse of EdU results in cell labeling that is restricted to the K10- progenitor cell population in wild type (WT) and oncogenic Pik3ca-expressing epidermis. Statistics based on n = 3 animals of each condition. Error bar: SD, center value: mean. Scale bar, 50 μm. (c) and (d), Representative flow plot (c) and statistics (d) show that in the EdU⁺ only population isolated from EdU-BrdU pulse-chase labeled epidermis, only ~3% cells are arrested at G2 (2n population), and there is no significant difference in the size of the G2 arrested population in WT and Pik3ca 2X epidermis. Statistics based on n = 3 WT animals and 5 Pik3ca 2X animals. Two-tailed t test, P-value as indicated. Error bar: SD, center value: mean. (e), Representative cell labeling in the EdU-BrdU pulse-chase assay. Experiment was repeated 3 times independently with similar results. EdU marks cells that have replicated their DNA over the 8 hours of the experiment. BrdU labels replicating cells during the last 6 hours of it. EdU⁺ only expression marks daughter cells that were given sufficient time to commit to progenitor or differentiated fate, as reported by expression of differentiation marker K10. Scale bar, 50 μm. Statistical source data for (a,d) are shown in Supplementary Table 4.