Fatema Akter Sadia

More than 30% of all human malignancies are brought about by mutations in RAS proto-oncogenes (HRAS, KRAS, and NRAS) that are greatly conserved in yeast RAS1 and RAS2. This makes yeast (Saccharomyces cerevisiae) an efficient single-celled eukaryotic model organism to study their functions. In the current investigation, the null mutation of the RAS2 gene was analyzed to find out its deleterious consequences in yeast cells based on their ability to utilize glycerol as a respiratory substrate, mtDNA mutation rate, mtDNA abundance, and distribution pattern. Mutant cells grown in YPEG plates demonstrated slight respiratory deficiency compared to the wild type. An erythromycin-resistant assay was carried out to analyze the spontaneous mitochondrial DNA mutation rate in the Δras2 mutant and it was found to be greater than that of wild type. In addition, the mitochondrial DNAs of both strains were also visualized under a fluorescence microscope using DAPI fluorescent stain. It was observed that mtDNA abundance was much lower compared to wild type cells. Thus, the present investigation revealed that deletion of the RAS2 gene resulted in mtDNA mutation and depletion.