BM Ly6C^hi monocyte subpopulations represent two distinct mobilizable pools. (A and B) BM monocyte subsets (cMoP, CXCR4^hi and CXCR4^lo Ly6C^hi monocytes, and Ly6C^lo monocytes) were quantified for their numbers (A) and their normalized CXCR4 MFI (B) at ZT5 and ZT13. Results are expressed as mean ± SD (n = 4–5) and representative of one out of three experiments. ns, not significant; *, P < 0.05; **, P < 0.01 (Student’s t test). (C) BM monocyte subset counts after LPS administration. Results expressed as mean ± SD (n = 5) and representative of one out of five independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (one-way ANOVA). (D) BrdU⁺ CXCR4^hi and CXCR4^lo subset counts after 2 h of LPS administration. Results expressed as mean ± SD (n = 5) and representative of one out of three independent experiments. ns, not significant; ***, P < 0.001 (Student’s t test). (E) CCR2 expression (left) and CCR2 MFI (arbitrary units; right) of CXCR4^hi and CXCR4^lo subsets. Results are expressed as mean ± SEM (n = 5). ****, P < 0.0001 (Student’s t test). (F) Chemotaxis assay of CXCR4^hi and CXCR4^lo subsets towards CCL2. Results expressed as mean ± SD (n = 5) and representative of two independent experiments. *, P < 0.05; **, P < 0.01 (two-way ANOVA).