Fig. 3.

Shortened and morphologically abnormal growth plate and abnormal expression of chondrogenic markers in the growth plate of TSK−/− mutant femurs. (A) Images of sagittal sections of 3-week-old TSK−/− mouse femurs stained with β-gal staining (blue) showing TSK expression patterns in the femur. Counter-staining was performed with nuclear fast red. Expression of TSK was observed in chondrocytes in the growth plate and in cells around the trabecular bone and cortical bone in the femurs of TSK−/− mice. No endogenous β-gal activity was observed in the femurs of WT mice. (B) Images of sagittal sections of 3-week-old WT and TSK−/− mouse femurs stained with haematoxylin and eosin. The columnar arrays of chondrocytes are disturbed in TSK−/− mice. (C) Images of sagittal sections of 3-week-old WT and TSK−/− mouse femurs stained with toluidine blue. Growth plate thickness was reduced in TSK−/− mice. (D) Quantitative analysis of growth plate thickness at the resting, proliferating, and hypertrophic zones in 3-week-old WT and TSK−/− mice. The thickness of each zone was measured at 10 points. Results are expressed as the mean from 3 mice in each group (*p < 0.05 vs. WT littermates, n = 3). (E) Chondrogenic marker mRNA levels in growth plate cells of WT and TSK−/− mice obtained by microdissection according to RT-PCR (*p < 0.05 vs. WT littermates, n = 5).