Mutator flies accumulate an excess of deleterious mtDNA mutations.

(A) The mutation frequency of 1-day-old 1xPolGmut flies per codon position. (B) The mutation frequency at four-fold degenerate (synonymous; S) and non-synonymous (NS) sites. (C) The distribution of PhyloP scores from 10,000 trials of simulated mutagenesis of the Drosophila mitochondrial genome under conditions of neutrality. The blue line indicates the observed average PhyloP score from 1-day-old 1xPolGmut flies. (D) The distribution of NS/S ratios observed from 10,000 trials of simulated mutagenesis of the Drosophila mitochondrial genome under conditions of neutrality. The blue line indicates the observed average NS/S ratio in 1-day-old 1xPolGmut flies. (E) The distribution of MutPred scores from 10,000 trials of simulated mutagenesis of the Drosophila mitochondrial genome under conditions of neutrality. The blue line indicates the observed average MutPred score in 1-day-old 1xPolGmut flies. p-values for A and B determined through pooled sample Z-test. p-values in panels C-E determined empirically.