Radiographs of spines from wild-type versus ank/ank mice. Eight-week-old mice appear in (A) and (B); 12-week-old mice in (C) and (D); and 18-week-old mice in (E) and (F). Red arrows in (B) show spurs between the vertebral bodies of 8-week-old ank/ank mice. Red arrows in (D) show early syndesmophytes at the edges of the vertebra from 12-week-old ank/ank mice. Red arrows in (F) show extensive marginal syndesmophyte formation between vertebral bodies from 18-week-old ank/ank mice.