MKO neutrophils have impaired homing to the bone marrow. Bone marrow cells (8-10 × 10⁶) from control (CTL) or MKO mice carrying the Ly 5.2 allele were adoptively transferred to WT recipients carrying the Ly 5.1 allele, enabling detection of infused neutrophils in the bone marrow by flow cytometry using an allele-specific CD45.2 antibody. (A) Representative dot plots showing donor neutrophils as the percentage of total bone marrow neutrophils 1.5 to 2.5 hours after infusion. (B) The percentage of transferred control or MKO neutrophils present in the bone marrow of recipient mice. Data represent the mean ± SEM of n = 8 to 12 recipients for each genotype from 3 separate experiments. *P < .05 compared with control neutrophils.