Nucleic Acids Research, 1984, Vol. 12, No. 6 2717-2729
© 1984
MOLECULAR BIOLOGY |
Evidence for transcriptional regulation of the myosin heavy chain gene during myogenesis
M.R.C. Research Unit for Molecular and Cellular Cardiology, Department of Medical Biochemistry, University of Stellenbosch Medical School P.O. Box 63, Tygerberg 7505, South Africa
1To whom correspondence should be addressed
Received December 20, 1983. Revised February 27, 1984. Accepted February 27, 1984.
One of the changes accompanying skeletal muscle cell (myoblast) fusion is a dramatic increase in synthesis of muscle specific proteins, one of which is myosin. The underlying mechanism for this burst in synthesis is not yet understood but may occur by two mechanisms: (a) gradual storage of mRNA and translational control as found by others or (b) gene activation and rapid synthesis of mRNA for immediate translation. In this paper we show that the myosin gene changes its organization such that postfusion skeletal muscle cells show an increased susceptibility to DNase I, a recognized probe for gene activation. We also show that this change accompanies an increase in rate of transcription and an increased cell content of myosin heavy chain mRNA. This work shows that transcriptional control is an important mechanism during muscle cell development in addition to the translational control shown by other workers