Quantification of myosin heavy-chain mRNA during myogenesis

Complementary DNA (cDNA) was synthesized from a 26-S poly(A)-containing RNA fraction consisting predominately of myosin mRNA, and used to quantitate the amounts of myosin mRNA during development. RNA . cDNAmyosin hybridizations were performed with RNA isolated from tertiary cultures of chick fibroblasts, and the proportion of myosin RNA determined. The levels of myosin RNA present in primary chick myoblast cultures undergoing development were also analyzed by RNA . cDNAmyosin hybridizations. Correlation of these values with the rate of myosin heavy chain synthesis indicates that myosin mRNA is subject to post-transcriptional or translational control.