Increased cell size and number of nuclei per cell in WASp-/- osteoclasts. The area of spreading (A, B) and the number of nuclei per cell (C, D) was quantified on normal (▪) and WASp-null (▦) osteoclasts derived on glass coverslips (A, C) or bone slices (B, D). Cells were fixed and stained with Alexa 468-conjugated phalloidin and propidium iodide. Graphs express the mean ± SEM values from 3 experiments. ^*P < .05 (Student t test).