Fig. 4.
Chondrocyte differentiation and proliferation. Chondrocyte differentiation and proliferation were examined in E15.5 embryonic bone growth plates of the radius (A, D), ulna (B, E) and humerus (C, F) of Chkb−/− and WT mice by Sox9 (A, B, C) and PCNA (D, E, F) immunohistochemistry. The percentage of positively stained cells was quantified (G, H). Data are means ± SEM from 3–4 littermates of each genotype; *: P < 0.05 compared to WT.