Fig. 5: Negative selection shapes the mt-genome.
From: Mitochondrial somatic mutation and selection throughout ageing
a, The count of genes under positive (blue) and negative (red) selection. Mutations and mutation type proportions were quantified in three different ways: (1) all mutations, without consideration of mutation frequency or mt-genome position, (2) all mutations excluding the D-loop, and (3) mutation counts binned by mutation frequency, excluding the D-loop. Mutations with a frequency greater than 1 × 10−3 were excluded from analyses 1 and 2. b, The proportion of each mutation type. Proportions are calculated as the count of mutations of each type divided by the total count of mutations in a given bin. The average mutation type proportion across experimental conditions (n = 29 conditions; strain × tissue × age) is shown with error bars denoting the standard error of the mean. In blue are proportions for the aggregated mutation counts with (dark blue) and without (light blue) the D-loop. Mutations are ordered in descending order of average mutation frequency. c, The frequency spectra for non-synonymous (purple) and synonymous (orange) mutations. The bar denotes the average proportion of non-synonymous and synonymous mutations in a bin. The proportion is calculated as the count of non-synonymous or synonymous mutations in a frequency bin relative to the total count of non-synonymous or synonymous mutations across all bins. The average proportion is taken across tissues and age in a strain (n = 6 except for B6, where n = 5). Each point represents the proportions that compose the average. The error bars denote the standard error of the mean. For these analyses mutation counts were aggregated across samples in an experimental condition.
