Restricted expression of cardiac myosin light chain 2A gene in muscular dystrophic condition

In order to understand the mechanism of defective myofibrilogenesis in muscular dystrophy, we have used the genomic cloned DNA specific for myosin light chain 2A (MLC 2A) to check its expression. The fusion of a partial digest of lambda LC5, containing the upstream sequence of MLC 2A gene with the expression vector of PSVOCAT has already been reported. Using this CAT-fused recombinant containing 1.6 kb of MLC 2A gene, we were able to detect the promoter activity in normal heart cells, H9C2 cell line whereas a restricted expression of MLC 2A gene was noticed in muscular dystrophic muscle cells from heart and skeletal. We have also measured the transient transfection efficiency by contransfecting with the plasmid LacZ. Simultaneous assay of beta-galactosidase and CAT in the cell extract was performed. With beta-galactosidase as control, we confirmed that the promoter activity of MLC 2A gene is inhibited in muscular dystrophy though there is a normal rate of transfection occurred.