Expression of alpha and beta tropomyosin subunits during early myogenesis in somites and limb buds of chick embryos.

The appearance of alpha and beta subunits of skeletal tropomyosin in early myogenesis was studied histochemically using monoclonal antibody to alpha tropomyosin and affinity-purified polyclonal antibody to beta tropomyosin. In muscle cells, in both somites and limb buds, the alpha and beta subunits are simultaneously expressed and first appear in the somites at the 30-36 somites. The relatively greater amount of beta than alpha tropomyosin found in early myogenesis is thus likely to result from a higher rate of beta tropomyosin synthesis.