(A) TRAP staining and (B) histomorphometric analysis of the histological sections obtained from the metaphysis region of distal femurs of the twelve week old male Def6−/− mice and their littermate control mice, N. Oc./BS, number of osteoclasts per bone surface; Oc. S/BS, osteoclast surface per bone surface. n = 5 per group. **p < 0.01. Scale bar: 100 μm. Microcomputed tomography (μCT) images (C) and the bone morphometric analysis (D) of trabecular bones of the distal femurs isolated from the twelve week old male Def6−/− mice and their littermate control mice. Scale bar: 1 mm. BV/TV, bone volume per tissue volume; Tb. N, trabecular number; Tb. Th, trabecular bone thickness; Tb. Sp, trabecular bone spacing. n = 5 per group. *p < 0.05; **p < 0.01.