Changes to the mtDNA copy number during yeast culture growth

Abstract

AbstractThe yeast mitochondrial network is dynamic, with frequent fusion and fission events among mitochondria. Notable changes in mitochondrial morphology and function accompany changes in physiological state. Differences in mtDNA copy number among strains and growth conditions have been observed, but it has not been previously shown that the mtDNA copy number changes substantially over time in a clonal growing culture. Here we show that there are fairly dramatic (3x-5x) changes to the mtDNA copy number per cell in growing cultures of Saccharomyces cerevisiae, on a timescale of hours to days. While these changes appear to be connected to the shift from fermentation to respiration, it is possible that they are more simply associated with changes in growth rate. Our work suggests that the mtDNA copy number is a dynamic phenotype, a finding that has important implications for studies of the regulation of mtDNA copy number.