We previously reported that consistent levels of c-fms-related transcripts are expressed during the growth of rat myogenic cells as well as in all neoplastic myoblasts. The present study extends this observation to mouse myogenic cells and demonstrates that a tyrosine-kinase-associated gp170, very similar or identical to the receptor for the macrophage stimulating factor CSF-1, is synthesized in myoblasts via a short-lived precursor of 115-116 kD and an immature gp130. These gene products are eliminated during the myogenic process, suggesting their role in the proliferation of muscular cells.