Purpose: Duchenne Muscular Dystrophy (DMD), a degenerative muscle disease, is caused by a defect in a 427kD membrane associated protein, dystrophin. The dystrophin gene also encodes for shorter isoforms believed to be play a part in DMD associated defects; including night blindness, dilated cardiomyopathy, and mental retardation. The purpose of this work was to determine which tissues expressed isoforms Dp71, Dp116, Dp140, and Dp260.Methods: mRNA from several wild type C57BL/6J mouse tissues was isolated and cDNA made using random hexamers. Tissues included cardiac muscle, skeletal muscle, brain, intestine, kidney, liver, lung, retina, spleen, stomach, and thymus. Primers for each of the four isoforms were designed using sequences from GenBank. The forward primers were located in novel 5-prime sequences of each isoform and reverse primers were located two exons downstream. PCR amplification was carried out and products detected by gel electrophoresis. PCR products were cloned into bacteria plasmids and sequenced. Results: Dp71 and Dp260 were present in all tissues tested. Dp116 was found predominately in cardiac muscle, intestine, lung, skeletal muscle, and stomach. Dp140 was also found to be highly expressed in cardiac and skeletal muscles as well as brain, stomach, and retina.Conclusion: RT-PCR shows isoforms present in more tissues than previously revealed by Western blot analysis, suggesting that RT-PCR may be a more sensitive assay in the detection of these isoforms. The prevalence of Dp71 and Dp260 in all tissues implicates these isoforms as having a fundamental role in normal function. Variability of Dp116 and Dp140 expression in tissue suggests a more specialized function for these two isoforms, and makes them strong candidates for further investigation into DMD associated disorders.
About this article
Cite this article
Tokarz, S., Duncan, N., Dewan, A. et al. Dystrophin Isoform Distribution in Normal Mouse Tissues. † 635. Pediatr Res 41, 108 (1997). https://doi.org/10.1203/00006450-199704001-00655