EXPERIMENTAL FIGURE 20-7 Inactivating the genes for some ECM proteins results in defective skeletal development in mice. These photographs show skeletons of normal (left), collagen II–deficient (center), and perlecan-deficient (right) murine embryos that were isolated and stained to visualize the cartilage (blue) and bone (red). Absence of these key ECM components leads to dwarfism, with many skeletal elements shortened and disfigured.

[Republished with permission of John Wiley & Sons, Inc., from Gustafsson, E. et al., “Role of collagen type II and perlecan in skeletal development,” Ann. NY Acad. Sci., 2003, May; 995:140–50; permission conveyed through the Copyright Clearance Center.]