Figure 2.

RANKL induces OC formation from TRAF6^−/− OCPs cultured on bone slices. 2 × 10⁵ spleen cells from 7- to 11-day-old WT (+/+) and TRAF6^−/− mice were seeded on bone slices in 96-well plates and cultured with RANKL+M-CSF for 9 days. A, TRAP+ OCs are shown on bone slices (left panel) and on the plastic around the bone slices (right panel) in the same well. TRAP-positive osteoclast numbers (Oc.N) and areas (Oc.Ar) on the bone slices and on the plastic around the slices were counted and expressed per slice or per well after removal of the slices. B, the bone slices were brushed to remove cells and stained with 0.1% toluidine blue to highlight resorption pits (left panel). Pit areas were counted and normalized to slice area. **, p < 0.01 versus values for WT cells. All experiments were repeated at least twice with similar results.