Mitochondrial genetics is extraordinarily complex, as there are hundreds to thousands of mitochondrial genome (mtDNA) copies per cell, and mtDNA is heteroplasmic. Mutations in mtDNA are associated with many age-related pathologies such as Parkinson's Disease and cancer, as well as other diseases, yet the origin and transmission of mtDNA mutations remains poorly understood due in part to this genetic complexity. Recent advances in sequencing technologies have contributed to improved knowledge of mtDNA inheritance and mutagenesis, yet the error rate of variant calling is similar to the rate of mtDNA mutations. Therefore, we have applied a novel sequencing technology, called Duplex Sequencing (DS), to the C. elegans model for the first time. This sequencing technology allows for extremely sensitive detection of ultra-rare variants, with an ability to capture one mutation among 107 nucleotides - a thousand-fold increase in sensitivity from traditional sequencing technologies. We performed this in wildtype N2 C. elegans, N2 exposed to ultraviolet C radiation (UVC), and two mitophagy deficient strains,
pink-1 and
dct-1. Overall, in a pilot analysis, we determined a mtDNA mutation frequency of 3.07 x 10-5 in wildtype, with a 1.6-fold higher frequency in UVC-exposed C. elegans (4.89 x 10-5). Interestingly, we see a 40% and 33% reduction in overall frequencies in
pink-1 and
dct-1, respectively (1.18 x 10-5 and 2.05 x 10-5). We observe a different signature of mutations with this method compared to other studies that have investigated mtDNA mutations in C. elegans. We detected a high rate of G:C > T:A transversion mutations across all samples, with an exacerbation of this rate in the UVC-treated C. elegans, and a suppression in mitophagy mutants. This suggests that oxidative damage may be the origin of mtDNA mutations in C. elegans, which is contrary to results obtained in mammals, and that inhibiting mitophagy may reduce the frequency of mtDNA mutations. Ongoing mutation accumulation experiments are examining the effect of cadmium and aflatoxin B1 exposures on mtDNA mutagenesis using Duplex Sequencing in these three strains of C. elegans.