Chemotactic behavior of myoblasts.

Earlier studies have suggested that myogenic cells of somite origin migrate into the developing limb, but little is known about the factors affecting the pattern of migration. In order to understand the migratory behavior of myogenic cells, embryonic skeletal muscle cells were tested for their ability to migrate chemotactically using a modified Boyden chamber assay system. It is shown here, for the first time, that embryonic skeletal muscle cells have the capacity to migrate toward a gradient of platelet-derived growth factor (PDGF) and PDGF-like factors present in serum and chick embryo extract (CEE). On the other hand, nonmyogenic limb mesenchyme cells do not exhibit such a response. A hypothesis is proposed here that chemotactic factors from the already patterned vasculature might influence the distribution of skeletal muscle cells during early limb development.