Higher magnification of spinal sections from 8-week-old wild-type (A) versus 8-week- (B), and 12-week-old (C) ank/ank mice. Arrows in (A) show a few osteoblasts lining the subchondral bone (SB). GP, VEP, and AF denote growth plate, vertebral end plate, and annulus fibrosus, respectively. Solid arrows in (B) show more-prominent osteoblasts in the vertebral body of an 8-week-old ank/ank spine. Dashed arrows show calcific deposits. Solid arrows in (C) show numerous osteoblasts lining the new bone that was formed in a 12-week-old ank/ank mouse. Embedded in the syndesmophyte (SYN) are osteocytes (short dashed arrows).