Streptomycin retards the phenotypic maturation of chick myogenic cells

As part of an effort to optimize conditions required for the complete maturation of muscle cells in vitro, we have investigated the effects of the antibiotics penicillin, streptomycin, and Fungizone (amphotericin B) on the development of cultured chick embryo skeletal muscle. It is shown that even low dosages of streptomycin, but not penicillin or Fungizone, retard protein synthesis and accumulation in these cultures. Myosin accumulation was also reduced and the appearance of striations in fused cells was delayed in myotubes formed in medium containing streptomycin. Additional data suggest that this overall retardation of myogenesis is due to the influence of streptomycin on maturing myotubes rather than early proliferation and cell fusion. These results are discussed with regard to recent efforts to promote the full maturation of muscle cells grown in culture.