Mutation research
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Mitochondria are vulnerable to the effects of ionizing radiation; damage to mitochondrial DNA (mtDNA) may be more extensive and persistent than damage to nuclear DNA (nDNA). Variation in mtDNA copy number has been proposed as a marker for mitochondrial dysfunction in response to ionizing radiation. We have developed a precise and sensitive duplex droplet digital PCR (ddPCR) method for quantitation of the mtDNA/nDNA ratio in the model organism Caenorhabditis elegans. ⋯ The variation followed a Hill-type dose response with threshold 10.3 ± 1 Gy. This strongly suggests that chronic genotoxic stress affects mtDNA replication. The duplex ddPCR method is a novel, high-precision, sensitive tool for determination of mitochondrial DNA copy number variation and function in C. elegans.