Figure S3.

Lineage Tracing of DPs in the Paw Epidermis Also Recapitulates Tissue Expansion, Related to Figure 4

(A) Whole-mount paw epidermis from newborn (P1) and adult (P60) mice. (B) Measurement of the length of the paw from P1 to P60 (n ≥ 5 mice). (C) Measurement of the paw width from P1 to P60 (n ≥ 5 mice). (E) Calculated total paw surface showing a linear increase from P1 to P15 reaching a plateau after P21 (n ≥ 5 mice). (E-F) Whole-mount paw epidermis (E) and quantification of BrdU positive BCs (F) analyzed in P1, P7, P15 and P30 epidermis 4h after a pulse of BrdU. (G-H) Representative pictures of whole-mount paw epidermis from K14-CreER/Rosa-Confetti mice induced with 10μg of Tamoxifen at P1 and collected at P4 (G) and P30 (H). Scale bar = 1mm. (I-J) Quantification of the number of basal (I) and total (J) cells per clone in paw epidermis counted on confocal pictures from P4 to P60 and showing the expansion of the clones over time. N: number of analyzed clones, brackets: average clone size. (K) Quantification of the number of clone per paw epidermis overtime. (L) Cumulative distributions of paw basal clone size, rescaled by average clone size at all time points (purple, green, blue, orange and yellow dots resp. for P4, P7, P15, P30 and P60). In all cases, the rescaled distributions are well-described by a simple exponential distribution (black line). Data are represented as mean ± SEM (M-O) The theoretical model predicts well the experimental measures of the basal clone size expansion (M), the decreasing proliferation rate (N) and the clonal persistence (O) in the paw epidermis. Symbols, experimental data; green lines, model predictions. Data are represented as mean ± SEM.