Fig. 1

IFE basal cells in the abdominal skin of pregnant mice are highly proliferative. a Abdominal circumferences of virgin and pregnant (8–16 dpc) mice. Data represent the mean ± standard error of the mean (s.e.m.) (n = 3 mice); **P < 0.01, analysed by the two-tailed t-test. b Immunofluoresence of Ki67 (green) and Hoechst (blue) on dorsal (upper) and ventral (bottom) skin from virgin and pregnant (8–16 dpc) mice. c Quantification of Ki67⁺ cells in IFE basal layers. d Immunofluoresence of EdU (green) and Hoechst (blue) on dorsal (upper) and ventral (bottom) skin from virgin and 16 dpc mice. e Quantification of EdU⁺ cells in IFE basal layers. f Two-photon microscopic images of ventral skin in Fucci2 virgin and 16 dpc mice, where cells in G1 and S/G2/M phases exhibit red or green fluorescence, respectively. g Quantification of cells in S/G2/M phases in ventral skin IFE of Fucci2 mice. Data represent the mean ± s.e.m. of averages of seven sections (n = 7) pooled from three mice. More than 700 cells were analysed to calculate the average in each section; **P < 0.01, analysed by the two-tailed t-test. c, e Data represent the mean ± s.e.m. of averages of three independent experiments (n = 3). More than 500 cells were analysed to calculate the average in each experiment; **P < 0.01, ***P < 0.001, analysed by Dunnett’s multiple comparison test. b, d White-dotted lines indicate basement membranes. Experiments were repeated three times with three mice for representative images in (b, d, f)