FIGURE 3.

Quantification of the histopathological changes of the knee. A, total score indicates increased severity of joint histopathology in mutants at 4 and 7 months of age. By 12 months, the differences between controls (ctr) and mutants (mt) are not significant (ns). Open symbols, female mice; filled symbols, male mice. B, quantification of cartilage erosion reveals no significant difference in articular cartilage destruction between controls and mutants. Horizontal lines in A and B represent the median values; n = 8/8 at 4 months, n = 10/10 at 7 months, and n = 10/10 at 12 months (where n = number of control mice/number of mutant mice). For each animal, 30 HE- and SO-stained sections representing the entire knee region were analyzed. Statistical differences between genotype groups were evaluated using the Mann-Whitney U test.