Preferential Subsarcolemmal Localization of Dystrophin and β-dystroglycan mRNA in Human Skeletal Muscles

The intracellular localization of dystrophin and beta-dystroglycan mRNA in skeletal muscles of patients with Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) and normal subjects was examined by in situ hybridization using biotinylated oligonucleotide probes. These mRNAs were found preferentially in sarcolemma in the skeletal muscles of both normal subjects and affected patients. Quantitative analysis of mRNA signals demonstrated no prominent reduction of dystrophin or beta-dystroglycan mRNA in DMD/BMD muscles. These results suggest that even mRNAs with deletions contain specific information that affects their localization, and the characteristic defect of dystrophin in DMD/BMD muscles seems to be caused mainly by the instability of dystrophin protein, as a post-transcriptional event.