Figure 3. Tgfa knockout mice express less MMP13 and less type II collagen neoepitopes than control littermates at 7 weeks post-surgery.

Histological sections were prepared from the knee joints of both Tgfa knockout and heterozygous mice at seven weeks post-surgery. Immunohistochemistry was performed with primary antibodies against MMP13 and type II collagen fragments. This was followed by secondary antibody incubation and visualization with the substrate DAB (brown precipitate). Nuclei were counterstained with hematoxylin (blue). Representative images show that knockout animals express less MMP13 and type II collagen fragments than heterozygous controls.