Genes Cam and nAchR-30D suppress mutant dystrophin phenotype in Drosophila melanogaster. Natalia Holub, Ruslana Mykula, Yaroslava Chernyk. Departament of Genetics and Biotechnology, Ivan Franko National University, lviv, Ukraine.

   Muscular dystrophies - a group of genetic diseases that are classified as incurable and are accompanied by a gradual degradation of skeletal and cardiac muscles. At the basis of their development are disturbances in the structure and functioning of the dystrophin-glycoprotein complex (DGC), which connects actin cytoskeleton to extracellular matrix and stabilizes sarcolemma during contraction of muscles.Drosophila melanogaster is a good model for studying a new approach to treatment muscular dystrophy with using genes-modifiers. It has got homologues of all components of the DGC. The aim of work study was to examine the influence of genes nAchR-30D and Cam (involved in the functioning of muscle and cytoskeleton) as a possible genes-modifiers of mutant dystrophin phenotype in strain Dys Df//TM6,Tb. Genome of this strain contains deletion (170 kb) of dystrophin gene and adjacent to dystrophyn genes. Mutants are characterized by defective thorax muscular structure, decreased indexes of physical activity (IPA) and life span. Offsprings F₁ containing an supplementary copy of gene-modifier and mutant dystrophin gene were analysed after these variables. In all crossings we observed restore of thorax muscle structure at 56%-69% comparing to 0,11% in dystrophy mutants. In climbing-test was shown increasing of IPA in hybrids nAchR-30D//DysDf in 2-4 times and in hybrids Dys Df//Cam in 3-5 times compared to Dys Df//TM6Tb. Also, genes nAchR-30D and Cam caused increasing of average life span indexes on 90-143% and maximum life span on 62%. We can conclude that supplementary copies of genes Cam and nAchR-30D have a suppressive effect on expression of dystrophin mutant phenotype.