Expression of Notch receptors and ligands during osteoclastogenesis from mouse BM. BM cells cultured with rmM-CSF for 72 hours were used as osteoclast precursors (Day 0). These cells were further cultured with rmM-CSF and rhRANKL to induce osteoclasts. (a) CD11b+F4/80+ osteoclast precursors and CD11b+CD61+ osteoclasts were analyzed on days 0, 3 and 5. Percentages from three independent experiments are indicated. (b) Expression of Notch receptors and ligands on CD11b+F4/80+ osteoclast precursors was analyzed by flow cytometry on days 0, 3 and 5. Expression on CD11b+F4/80- cells on Day 3 is also represented. CD11b+CD61+ osteoclasts were analyzed on Day 5. For comparison, BM cells were cultured with rmM-CSF alone for eight days and CD11b+F4/80+ cells were analyzed as BM-derived macrophages (BMMø), or with rmGM-CSF for eight days with LPS stimulation for the last 17 hours and CD11c+ cells were analyzed as BM-derived dendritic cells (BMDC). Filled histograms indicate the control hamster IgG. Open histograms indicate the Notch receptors or ligands. (c) Messenger RNA levels of Notch ligands were measured by RT-PCR on days 0, 3 and 5.