Restoration of CX₃CR1^hi Ly6C^lo monocyte survival. (A-B) Serum ELISA of indicated BM chimeras for the presence of secreted endogenous and transgene-encoded CX₃CL1 isoforms. (A) Detection with anti-CX₃CL1 antibody. (B) Detection of CX₃CL1^105Δ transgene encoded CX₃CL1 with anti-myc antibody (9E10). ND indicates not detectable. (C) Flow cytometric analysis of blood monocytes of WT mice, CX₃CL1^−/− mice, CX₃CL1^395AA:CX₃CL1^−/− mice, and CX₃CL1^{105 Δ}:CX₃CL1^−/− mice. (Top) Representative analysis of Ficoll-enriched WT blood cell sample indicating detection of Ly6C^lo and Ly6C^hi CD115⁺ monocyte populations. Bar diagram bar represents percentage of Ly6C^lo monocytes (R3) of total blood monocyte (R2) for indicated mouse strains. N = 3 or 4 per group in 6 independent experiments. Error bars represent mean ± SEM. ***P < .001 (1-way ANOVA followed by Bonferroni Multiple Comparison).