ABSTRACT
A partial cDNA clone for the Duchenne's muscular dystrophy (DMD) locus was used to investigate the expression of this locus in human muscle in vitro. Hybridization to a 14-kilobase RNA transcript was demonstrated in both fetal and mature human skeletal muscle and four lines of human muscle cells in culture. The DMD transcript was not detected in cultured cells outside the muscle lineage. In cultured muscle cells, gene expression was evident only in myotubes both before and after innervation with mouse spinal cord. Primary cultures of human myoblasts did not show the presence of the DMD transcript prior to fusion to form myotubes. An in vitro model is potentially an excellent system in which to investigate factors controlling expression of the DMD gene in normal muscle and how this expression is altered in cultured DMD muscle.
Subject(s)
Genes , Muscles/metabolism , Muscular Dystrophies/genetics , Transcription, Genetic , Animals , Cell Line , Cells, Cultured , Fetus , Humans , Hybrid Cells , Muscles/embryology , Muscles/pathology , Nucleic Acid HybridizationABSTRACT
A portion of the Duchenne muscular dystrophy (DMD) gene transcript from human fetal skeletal muscle and mouse adult heart was sequenced, representing approximately 25 percent of the total, 14-kb DMD transcript. The nucleic acid and predicted amino acid sequences from the two species are nearly 90 percent homologous. The amino acid sequence that is predicted from this portion of the DMD gene indicates that the protein product might serve a structural role in muscle, but the abundance and tissue distribution of the messenger RNA suggests that the DMD protein is not nebulin.
