a, Short-term kinetics: EdU (20 μg g−1) was injected intraperitoneally in C57Bl6/N mice at t = 0. Mice were euthanized at the indicated time points and the percentage of EdU+ cells (blue) and the geometric MFI of EdU+ cells (red) were determined by flow cytometry, showing rapid EdU incorporation. Percentage of EdU+ cells plateaus at ~30 min, and geometric MFI plateaus at ~75 min. Following a first round of cell division, ~50% of monocytic cells are labelled after 8–12 h (n = 3–8 mice, see Source Data). b, Long-term kinetics: (1–240 h) EdU was injected as in a and percentage of EdU+ monocytic cells in bone marrow (top) and blood (bottom) was determined by flow cytometry, showing labelling of ~50% of monocytic cells for ~2 days. Labelled cells were not detectable after three days. Points represent values from individual mice; data for each time point are pooled from two to three independent experiments (see Source Data). c, Parabiosis between Csf1rcre;Rosa26LSL-YFP and Csf1rcre;Rosa26LSL-tdTomato pairs as described in Fig. 3, paired for 1–8 weeks, and from Csf1rcre;Rosa26LSL-YFP partners separated after 4 weeks of parabiosis and analysed 4 weeks, 14 weeks and 24 weeks after separation. Scatter plots represent the MFI of individual TRAP+ MGCs for YFP (y axis) and tdTomato (x axis), and histograms represent the overlaid distribution of the MFI values for YFP and tdTomato in TRAP+ MGCs at the indicated time points. Data are mean ± s.d.; dots in graphs represent individual mice; n indicates the number of mice per group. Source data