Figure 2: Delayed endochondral ossification in Foxc1^ch/ch mice.

(a,b) Histological analysis of newborn WT and Foxc1^ch/ch littermate femurs (a) and sternums (b). Paraffin sections of femurs and sternums from newborn WT and Foxc1^ch/ch littermates were examined by haematoxylin and eosin (H&E) and Alcian blue staining. Scale bar, (a) 500 μm. (b) 200 μm. (c) Histological analysis of tibial growth plate chondrocytes of newborn WT and Foxc1^ch/ch littermates. H, hypertrophic chondrocytes; P, proliferating chondrocytes; R, resting chondrocytes. Scale bar 200 μm. (d) Quantitative analysis of the lengths of the resting and proliferating zone (Resting+Proliferating) and the hypertrophic zone (Hypertrophic) was performed using H&E-stained sections of the tibia. Data are shown as the mean±s.d. (n=6). *P<0.05 (versus WT); Student’s t-test. (e) Paraffin sections of tibia from E15.5 WT and Foxc1^ch/ch littermate embryos were examined by H&E staining and in situ hybridization using antisense probes against Col2a1, Sox9, Ihh, PPR and Col10a1. Scale bar, 500 μm. (f) Paraffin sections of tibia from E15.5 WT and Foxc1^ch/ch littermates were subjected to immunofluorescence analyses using an anti-MMP13 antibody. Scale bar, 500 μm.