The ultrastructure of mandibular condylar and rib cartilage from mice carrying the spondylo-metaphyseal chondrodysplasia (smc) gene.

The ultrastructural appearance of cartilage from a new mutant spondylo-metaphyseal chondrodysplasia (smc) is described. The matrix is abnormally rich in collagen fibres which often form a sheath around the chondrocytes. Collagen balls - spherical inclusions of collagen fibres - are a unique and characteristic feature of the matrix, and the chondrocytes contain large amounts of lipid.