Mutation rates and characteristics of the postzygotic mutations. (A) Schematic of the number of spontaneous mutations along with the developmental period. (B) The trinucleotide context of postzygotic mutations (validated mosaic mutations detected during deep-coverage WGS on five mice), germline mutations (de novo mutations accumulated in long-term breeding mouse lines) (see Supplemental Fig. S8), and somatic mutations (de novo mutations accumulated in ntES cell lines derived from mouse tail fibroblasts) (see Supplemental Fig. S7). (C) Hierarchical clustering of the mutation signatures. Human germline and postzygotic mutations were obtained by Jónsson et al. (2017) and Bizzotto et al. (2021), respectively. (D) Comparison of replication timing at the genome position where the mutation occurred. Significant differences were calculated using a chi-square test. Error bars indicate binomial 95% CIs. (E) Mutation occurrence frequency in genomic regions. Each nucleotide in the effective whole-genome coverage (EWC) regions was annotated with SnpEff software. “Upstream” and “Downstream” indicate 5000-bp regions of each gene. Significant differences were calculated using a chi-square test. Error bars indicate 95% CIs for the Poisson means.
