Fig. 2.

Osteoclasts and their precursors are affected by the absence of CD200. (A) Bone marrow cells from 6-week-old CD200-deficient and wild-type mice were subjected to flow-cytometric analysis with antibodies directed against c-fms, Mac-1, and C-kit, as surface markers. Note that the absence of CD200 did not affect the number of osteoclast precursor cells (Left). (Scale bars, SD; n = 5.) (B) Bone-marrow-derived macrophages from 6-week-old CD200-deficient mice were cultured in the presence of M-CSF (30 ng/ml) and increasing concentrations of RANKL for 5 days to induce the differentiation of osteoclasts (Left). Bone marrow macrophages that lacked CD200 formed fewer osteoclasts than wild-type cells (Right). (Scale bars, SD; n = 5.)