Figure 4. Mutation rates are constant across the backgrounds and within the nearly homozygous (NH) lines (range 0.67–1.9 × 10−10 mutations/site/division; Kruskal-Wallis test, p>0.05).
The overall, mean single nucleotide mutation (SNM) rate in the 169 MA lines 1.1 × 10−10 per site per division is not different from previous estimates in various diploid Saccharomyces cerevisiae strains. NH lines represent the SNM rates in the NH lines. SNMs have been detailed in Supplementary files 5 and 6.
Figure 4—figure supplement 1. SNM spectrum across the nine hybrid backgrounds.
(A) The spectrum of single nucleotide mutations (SNMs) in the mutation accumulation (MA) lines is variable across all genetic backgrounds (Chi-square test, p<0.05; Supplementary file 5–6). (B) The transition to transversion ratio is similar across all genetic backgrounds, significantly increased only in H3 (Chi-square test, p<0.05; Supplementary file 5–6). (C) The GC > AT/AT > GC mutational bias was similar in all genetic backgrounds, significantly increased only in H1 (Chi-square test, p<0.05; Supplementary file 5–6).
Figure 4—figure supplement 2. The frequency of mutations was significantly impacted at C/G sites than A/T sites by the neighboring nucleotides (Chi-square test, p<0.05; Supplementary file 5–6).
Horizontal red lines indicate mean events.
Figure 4—figure supplement 3. The frequency of aneuploid chromosomes across the nine genetic backgrounds (H1–H9).
Two backgrounds carried ancestral trisomies, H3 (+1 chrIX) and H9 (+1 chrIX; +1 chrXVI).