CHARACTERIZATION AND NUCLEOTIDE-SEQUENCE OF THE CARDIAC ALPHA-MYOSIN HEAVY-CHAIN GENE FROM SYRIAN-HAMSTER

In small mammals, the cardiac alpha-myosin heavy chain (MyHC) gene is predominantly expressed in the adult ventricle, while the beta-MyHC ge ne is predominantly expressed in the fetal ventricle. In order to perf orm comparative studies of these genes, we sequenced the Syrian hamste r alpha-MyHC gene by determining a continuous 32415 base pair (bp) seq uence. It contained 39 exons encoding a predicted polypeptide of 1939 amino acid residues (aa) with a molecular weight of 223644Da. Sequence comparison revealed that the coding sequence is highly identical to t hat of the human alpha-MyHC gene. A marked feature of the Syrian hamst er alpha-MyHC gene was the abundance of reiterated sequences within in trons. Eleven B1 and four B2 retroposons were identified, a variety of di-, tri-, and tetra-nucleotide repeats were present, and three longe r direct repeats were found. Some of them appear to be associated with genetic recombination events.