Figure 4. Aggrecan and Type X collagen expression.

Immunofluorescent staining of Aggrecan (red; counterstain is green) in the growth plate of the proximal tibia from Col2a-Cre+;Kif3afl/fl (A,C) and control (B,D) mice at P10 (A, B) and P15 days (C, D). The hypertrophic zones are marked with white double arrows in A–D. The large white arrow in A indicates areas of histologically hypertrophic cartilage in the prehypertrophic zone of mutant growth plates at P10 days. The large white arrows in C represent the residual growth plate present in mutant mice at P15 days. In situ hybridization demonstrating Col10a1 expression in sections from growth plates of Col2a-Cre+;Kif3afl/fl (E) and control (F) P10 day tibia. Merged dark field and phase contrast images are shown. The black arrow in E represents an area in the mutant growth plate where hypertrophic cells are observed within the prehypertrophic region.