IL17A-/- mice have normal bone mineral densities and osteoclast formation. (a) High-resolution micro-computer tomography analysis of 8-week-old male mouse femur midshaft and distal trabecular bone from IL-17A and wild-type (Wt) mice. (b) Serum receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) levels of 8-week-old to 10-week-old IL-17A-/- mice and control mice. (c) Upper: bone marrow macrophages isolated from IL-17A-/- mice cultured for 6 days in the presence of macrophage colony-stimulating factor (MCSF)and RANKL form multinucleated tartrate-resistant acid phosphatase (TRAP)+ cells. Bars: 50 μm. Lower: Phalloidin, DAPI staining, and merged image of both stains of bone marrow macrophages isolated from IL-17A-/- mice and control mice cultured for 6 days in the presence of MCSF and RANKL showing F-actin ring formation. Bars: 25 μm. (d) Scanning electron photomicrographs of BMM cultures showing mature osteoclast resorbing activity (resorbed dentine has a rough, lighter colour appearance). Bars: 50 μm. Representative data of three experiments performed in triplicate. (e) Mean percentage area of dentine resorption of IL-17A and Wt mice.