Fig. 2: Gene essentiality polymorphism in yeast.
a A typical example of a genomic region with transposon insertions in each strain. Stain names are shown on the left side of the panel. Eight annotated essential genes (red bars) have part or all of their coding regions virtually transposon-free, while the 15 annotated nonessential genes (blue bars) tolerate transposons in all of their coding regions. Horizontal bars mark gene locations, with gene names provided below the bars and white arrows indicating transcriptional directions. Each vertical gray line represents one transposon insertion and the darkness of the line is proportional to the number of sequencing reads. b Three examples of gene essentiality polymorphism in the 16 yeast strains. The red boxes highlight strains where the gene is (virtually) transposon-free. c Gene essentiality polymorphism in the 16 strains. Each column represents a gene while each row represents a strain. Red, essential genes; blue, nonessential genes; gray, essentiality undetermined. The phylogeny of the 16 strains as in Fig. 1b is shown on the left, but the branches are not drawn to scale. d Distribution of the observed number of essentiality changes per gene along the phylogeny of the 16 strains, compared with the Poisson distribution with the same mean. P-value is from a one-tailed chi-squared test comparing the variance of the observed distribution with the corresponding Poisson variance. e Distribution of the observed number of essentiality changes per gene along the 16-strain phylogeny for the 567 genes exhibiting essentiality polymorphism, compared with the corresponding distribution of the number of nucleotide switches per SNP along the phylogeny for 567 randomly picked SNPs with levels of polymorphism matching levels of gene essentiality polymorphism. P-value from the two-tailed Wilcoxon signed-rank test that compares the mean ranks of the two distributions is presented. We perform 1000 replications of sampling of 567 SNPs and find P < 2.9 × 10−52 in every replication. Source data are provided as a Source Data file.
