PREMATURE SUTURE CLOSURE AND ECTOPIC CRANIAL BONE IN MICE EXPRESSING MSX2 TRANSGENES IN THE DEVELOPING SKULL

The coordinate growth of the brain and skull is achieved through a ser ies of interactions between the developing brain, the growing bones of the skull, and the fibrous joints, or sutures, that unite the bones, These interactions couple the expansion of the brain to the growth of the bony plates at the sutures, Craniosynostosis, the premature fusion of the bones of the skull, is a common birth defect (1 in 3000 live b irths) that disrupts coordinate growth and often results in profoundly abnormal skull shape. Individuals affected with Boston-type craniosyn ostosis, an autosomal dominant disorder, bear a mutated copy of MSX2, a homeobox gene thought to function in tissue interactions. Here we sh ow that expression of the mouse counterpart of this mutant gene in the developing skulls of transgenic mice causes craniosynostosis and ecto pic cranial bone, These mice provide a transgenic model of craniosynos tosis as well as a point of entry into the molecular mechanisms that c oordinate the growth of the brain and skull.