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 gene is predominantly expressed in the fetal ventricle. In order to perform comparative studies of these genes, we sequenced the Syrian hamster alpha-MyHC gene by determining a continuous 32,415 base pair (bp) sequence. It contained 39 exons encoding a predicted polypeptide of 1939 amino acid residues (aa) with a molecular weight of 223,644 Da. Sequence comparison revealed that the coding sequence is highly identical to that of the human alpha-MyHC gene. A marked feature of the Syrian hamster alpha-MyHC gene was the abundance of reiterated sequences within introns. Eleven B1 and four B2 retroposons were identified, a variety of di-, tri-, and tetra-nucleotide repeats were present, and three longer direct repeats were found. Some of them appear to be associated with genetic recombination events.