SCATTER FACTOR HEPATOCYTE GROWTH-FACTOR (SF HGF) INDUCES EMIGRATION OF MYOGENIC CELLS AT INTERLIMB LEVEL IN-VIVO/

The initiating event in the migration of myogenic cells to the limb bu ds is an epitheliomesenchymal transformation of cells located at the l ateral edge of the dermomyotome. Recently, a targeted mutation of c-me t in mice demonstrated an essential role of this tyrosine kinase recep tor and its ligand, scatter factor/hepatocyte growth factor (SF/HGF), in the migration of myogenic cells to the limb buds. Here, we show tha t ectopic application of exogenous SF/HGF induces emigration of Pax-3- positive myogenic cells into the lateral plate mesoderm. During this p rocess, the lateral portions of the dermomyotomes deepithelialize and the basement membrane disintegrates. Detaching myogenic cells do not l ose N-cadherin from their surfaces. We conclude that an HGF/SF- and c- met-mediated signal detaches myogenic precursor cells from the somites and thus plays a necessary role in the initiation of myoblast migrati on. (C) 1996 Academic Press, Inc.