The two DRG macrophage subsets display different turnover by monocytes. (A) Subclustering of DRG monocyte/macrophage clusters from flow cytometry data presented in Fig. 4 E. n = 4 mice pooled. (B) Expression of indicated markers across clusters. (C) Expression heatmap of selected markers in indicated populations. (D) Expression of Retnla and Ear2 (genes expressed in recently infiltrated monocytes, Sanin et al., 2022) within monocyte/macrophage clusters. (E) Immunolocalization of CCR2⁺ monocytes and CD64⁺CCR2⁺ macrophages adjacent to the DRG capsule. Scale bar, 50 μm. (F) Analysis of chimerism in CD45.2 mice 12 wk after whole body irradiation and i.v injection of 5 × 10⁶ CD45.1 bone marrow cells. Frequency of indicated cell populations that are of donor origin (CD45.1⁺), analyzed by flow cytometry. n = 6 mice, one experiment. Student’s unpaired t test. ***P < 0.001. RPM, red pulp macrophage. KC, Kupffer cell. MG, microglia. (G) CD45.2 mice received irradiation of only the hindlegs followed by i.v injection of 5 × 10⁶ bone marrow cells from CD45.1:Cx3cr1^GFP/+ mice. Donor chimerism was assessed by immunostaining in tissue sections, analyzing GFP frequency in Iba1⁺ parenchymal microglia, Iba1⁺CD163⁻ or Iba1⁺CD163⁺ DRG macrophages at the indicated time points after irradiation. n = 7, 5, 5 mice. One experiment/time point. Multiple unpaired t tests with Holm-Sidak correction. **P < 0.01, ***P < 0.001. (H)Cx3cr1^CreER/+R26^EYFP/+ mice were given 4 × 2 mg tamoxifen injections i.p and YFP⁺ frequencies analyzed in indicated cell populations using flow cytometry after 72 h (0 w) or 12 wk (n = 6, 11 mice). Two experiments pooled. Sidak’s multiple comparisons test. **P < 0.01, ***P < 0.001. Mouse illustrations in F–H were created with https://BioRender.com.