Fig. 1

Fetal-derived resident macrophages dominate in the mammary gland after birth. a Flow cytometric analyses of tissue-resident mammary gland (MG) macrophage populations in wild type (WT) mice. Shown are representative FACS plots and quantifications of F4/80^Int and F4/80^Hi macrophage populations among CD45⁺CD11b⁺Siglec-F⁻ cells at the indicated prenatal and postnatal time points. b Analyses of F4/80^Int and F4/80^Hi MG macrophages from CX3CR1-YFP reporter mice. The uppermost panel shows the experimental outline (tamoxifen induction at E13.5 and harvesting and staining of MG cells at the indicated time points). The representative FACS plots show backgating of the YFP⁺ cells (green) onto F4/80^Int macrophages (blue in newborn and black in 2 wk and 5 wk old mice) and F4/80^Hi macrophages (red in newborn and orange in 2 wk and 5 wk old mice). The quantifications show the frequency of YFP⁺ cells in each macrophage population. c Analyses of MG macrophages in WT mice treated with CD115 or control antibody at E6.5. Shown are representative FACS plots and quantifications of F4/80^Int and F4/80^Hi macrophage populations at the indicated time points. d Analyses of F4/80^Int and F4/80^Hi MG macrophage populations in Plvap^−/− and WT mice at the indicated time points. In all panels (a–d) MG macrophages were pre-gated as live CD45⁺CD11b⁺Siglec-F⁻ cells. In all panels (a–d) F4/80^Int macrophages have been gated in blue (in embryonic and newborn mice) or in black (in 1 wk – 3 months old mice), and the F4/80^Hi macrophages in red (in embryonic and newborn mice) or orange (1 wk – 3 months old mice). In the quantifications, each dot represents one mouse and mean ± SEM are shown. Data are from 3 (a E16.5, 1 wk and 5 wk, d 5 wk), 2 (a newborn, 2 wk and 3 months, b newborn and 5 wk, c 2 wk, d 3 wk) and 1 (b 2 wk, c E17.5 and 5 wk) independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001 (Kruskal–Wallis test). Source data are provided as a Source Data file