Fig. 7. Impaired angiogenesis and osteopenia in growth plates of Ctgf mutants. (A) Plastic sections through the growth plates of P0 femora stained by the method of von Kossa. The ECM of Ctgf mutants is mineralized (black stain), but hypertrophic chondrocyte columns (HC) are disorganized, and there are few capillaries (arrows) invading the cartilage matrix. A single capillary can be seen in the vicinity of the mutant growth plate. (B) von Kossa-stained plastic sections through neonatal femora from wild-type and Ctgf^-/- mice demonstrate that mutants are osteopenic; the amount of mineralization (black stain) is greatly reduced in mutants. The bone collar (brackets) adjacent to the expanded hypertrophic zone is lengthened in mutants, but is thinner than in wild-type littermates. Scale bars: 40 µm.