(A and B) Bright-field images and comparison of the width of the thoracic duct at 2 weeks after the first of 3 consecutive days of tamoxifen (Tmx) administrations among the indicated adult mice. Scale bars: 0.5 mm. Each dot indicates a value from 1 mouse, and n = 5 mice/group from 2 independent experiments. Data are shown as the mean ± SD; P value versus WT by 1-way ANOVA followed by Dunnett’s post hoc test. (C) Diagram showing intradermal injection of Evans blue into the right hind paw of the adult mice at 2 weeks after the first of 3 consecutive days of Tmx administration and analysis 30 min later. Bright-field images of the thoracic duct in the indicated mice. Similar findings were obtained from n = 5 mice in 3 independent experiments. Scale bars: 0.5 mm. (D) Generation of PG-WT and PG-Erg/Fli1^iΔLEC mice, diagram showing i.p. administrations of Tmx for 3 consecutive days in the adult mice, and 2 weeks later, an intravital imaging of mesenteric lymphatics at 9 h after oral gavage of 150 μL of BODIPY C11. (E–G) Fluorescence images and fluorescence intensity (FI) profile analysis of BODIPY C11 in the mesenteric lymphatics between PG-WT and PG-Erg/Fli1^iΔLEC mice at 9 h after the oral gavage. Yellow lines indicate the regions measured for profile analysis. Scale bars: 200 μm. Green shaded regions in the plots represent the mesenteric lymphatic lumens. LV, lymphatic vessel; BV, blood vessel. The letters F and G indicate the regions where BODIPY fluorescence was measured in F and G. (H and I) Comparisons of mean and retained BODIPY C11 FI in the mesenteric lymphatics of PG-WT and PG-Erg/Fli1^iΔLEC mice. Mean FIs of 3 regions within the lymphatics (Within LV) or adjacent nonlymphatic regions (Outside LV) are shown. Retained BODIPY C11 FI (ΔBODIPY FI) was defined as FI_{Within LV} – FI_{Outside LV}. Each dot indicates a value from 1 mouse, and n = 5 mice/group from 2 independent experiments. Data are shown as the mean ± SD; P value versus WT by 2-tailed Mann-Whitney U test.