Mouse mutants provide new insights into the role of extracellular matrix in cell migration and differentiation.

Migratory cell populations in the developing embryo disperse, localize and eventually differentiate in environments rich in extracellular matrix material. The extracellular matrix provides both a substratum for migration and a source of differentiative cues for the developing cells. Mutations in mice and other animals that alter embryonic interstitial environments are now providing information about the role of the extracellular matrix in these early developmental processes.