Fig. 1: Landscape of mtDNA heteroplasmy in normal cells.
From: Mitochondrial DNA mosaicism in normal human somatic cells
a, Experimental design. b, mtDNA mosaicism identified in 2,096 normal clones from 31 donors. Donor, developmental phylogeny, total number of mtDNA variants, maximum clone-VAF, tissue type and donor age for each clone are shown. Shared variants among clones from an individual are shown in yellow. c, Landscape of mosaic mtDNA variants. Variants were classified as heavy (external circle) or light (internal circle) strands according to the mutated pyrimidine. Mutation types and consequences are represented by colors and shapes. The heavy strand replication origin region (Orib-OH) is highlighted in yellow. d, Strand-asymmetric mutational spectrum across three tissue types. e, Strand bias of C:G>T:A and T:A>C:G base substitutions according to the heavy strand replication origin (Orib-OH; m.16,197-191). The log2-transformed ratio between the numbers of heavy and light strand mutations is shown. f, Distribution of clone-VAFs and phasing of mtDNA alterations in a fibroblast clone, 10_ARL10-4_001D4. H, heavy strand; L, light strand.