Figure 2. Atm^Ctsk mice have increased osteoclast numbers.

(A) Sections of the proximal tibia of 3-week- (upper panel) and 9-week-old (lower panel) Ctrl and Atm^Ctsk mice stained with van Gieson stain. Scale bar: 500 μm. (B) Bone histomorphometry of the proximal tibia. BV/TV, bone volume/tissue volume; Tb.Th, trabecular thickness; Tb.N, trabecular number; Tb.Sp, trabecular space; Oc.S/BS, osteoclast surface/bone surface; N.Oc/BS, number of osteoclasts/bone surface; ES/BS, erosion surface/bone surface; Ob.S/BS, osteoblast surface/bone surface; MAR, mineral apposition rate; BFR/BS, bone formation rate/bone surface. (C) Sections of the tibia (3-week-old mice) stained for TRAcP and counterstained with methyl green. Images of the primary spongiosa are shown. Scale bar, 100 μm. The number of osteoclasts/tissue volume (N.Oc/TV) at the edge of tibial primary spongiosa of 3-week-old mice. (D) Sections of the tibia (3-week-old mice) stained with Alcian blue. Images of the growth plate are shown. Scale bar, 100 μm. Growth plate width of 3-week- (upper panel) and 9-week-old Ctrl and Atm^Ctsk mice was measured. n = 7 and 6 for 3-week-old Ctrl and Atm^Ctsk mice, respectively, and n = 5 mice for each genotype at 9 weeks old. ns, not significant.