Fig. 1

Cell proliferation is necessary to restore the cell size when the epithelium is subjected to tension (A and B) A schematic (A) representing the proliferation inhibition paradigms used in this study and a bar graph (B) showing the effect of cell proliferation inhibition by ΔNp63 morpholino (ΔNp63 MO), hydroxyurea (HU), and flavopiridol (FVP) on cell divisions/h (no. of embryos: control, unstretched [NS] = 7 and stretched [S] = 7; HU, NS = 7 and S = 6; ΔNp63 MO, NS = 6 and S = 6; FVP, NS = 5 and S = 5) counted in live movies. Error bars denote SD. (C–F) Confocal micrographs of the Lyn-GFP-labeled periderm (C and E) and boxplots representing apical cell cross-sectional area measurements (D and F) of peridermal cells in NS and S embryos upon HU treatment (C and D) and ΔNp63 knockdown (ΔNp63 MO) (E and F) at 1 and 18 hpi. Quantification and statistical analyses were performed using n = the total number of cells collected from multiple embryos as indicated below the graphs (e, embryos; c, cells). Scale bar: 20 μm. Calibration bars: 0–29,411 a.u. (C) and 0–32,767 a.u. (E). hpi, hours post-injection; MO, morphant; NS, no stretch. ∗p < 0.05, ∗∗p < 0.01, and ∗∗∗p < 0.001 by Kruskal-Wallis test with Dunn’s post hoc test.