Myosin types during the development of embryonic chicken fast and slow muscles.

Publisher Website
Google Scholar
Abstract
The myosin types present in developing fast and slow muscles of the chicken embryo were studied. Myosin L chains were characterized by their mobility on sodium dodecyl sulfate/polyacrylamide gels; myosin H chains were identified by their reaction with antibodies specific for adult fast or adult slow myosin H chains. During development, the pectoralis muscle, a fast muscle in the adult, contained H chains and 2 of the 3 L chains characteristic of adult fast muscle myosin. The anterior latissimus dorsi muscle, a slow muscle in the adult, also contained fast myosin L and H chains during early development. Only after the time of innervation did this muscle begin synthesizing predominantly the slow myosin H and L chains. The synthesis of fast myosin in both early fast and slow muscles was the result of the endogenous program for muscle development; initiation of the synthesis of slow myosin was dependent upon exogenous factors.