Gene expression screening for specific genes associated with the skeletal muscles of patients with distal myopathy with rimmed vacuoles

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To obtain additional information about the pathogenesis of distal myopathy with rimmed vacuoles, it is important to determine the molecular bases of this myopathy. Because of small piece of the skeletal muscles from patients with DMRV,we first isolated and then identify the genes specifically expressed in the soleus muscles of experimental chloroquine (CQ)-treated rats, known as a animal model of human DMRV,using the defferential mRNA display technique (Liang and Pardee, 1992). Of a total of approximately 80 bands, 11 specific DNA fragments were obtained and cloned, and the DNA fragements of these genes were sequenced by the application of the method to an automatic DNA sequencer. In comarisons of gene expression in CQ-treated muscles and control muscles, the DNA fragments derived from mRNA expressed only in control muscles showed a high level of homology with the genes such as titin, F-1 ATPase, cytochrome C oxidase (CCO), myosin heavy chain, and flightless-1. While, DNA fragments expressed only in CQ-treated muscles showed a high level of homology with the genes such as protein phosphatase A2 regulatory subunit, alpha-trophomyosin, dehydroforate reductase, beta-tropomyosin, and nebulin. Furthermore, we obtained the two novel genes probably related to the CQ-treated muscles. ART-PCR analysis using primers derived from these sequences were performed to control differences in expression of these genes in DMRV and control muscles. Levels of F-1 ATPase, CCO,and flightless-1 expressions showed significant changes in the DMRV muscles as compared to the controls. The mutation of the Drosophila Amogaster gene flightless-1 is known to lead to loss of flight ability due to myofibrillar degeneration in the indirect flight muscles. Now, we are studying a role of flightless-1 in the pathogenesis of DMRV,and try to isolate the complete cDNA of two novel genes related to rat CQ-treated muscles.