Skip to main content
Fig. 6 | BMC Evolutionary Biology

Fig. 6

From: Adapting the engine to the fuel: mutator populations can reduce the mutational load by reorganizing their genome structure

Fig. 6

Top: Evolution of the mutational neighborhood of the Control (a, c) and the Mutator (b, d) lineages between generations 300,000 (red) and 390,000 (blue). In both cases the distribution of offspring evolves a deeper “U-shape” where the vast majority of offspring are either neutral or highly deleterious. In the Control lineages the increase in neutral offspring and highly deleterious offspring is balanced. In the Mutator strains, the U-shape becomes right skewed towards highly deleterious mutations and there is a strong reduction of slightly deleterious offspring. Bottom: Evolution of the mutational neighborhood of artificially reduced Mutator genomes (at generation 390,000) compared to the Mutator lineage at generation 300,000 (e, g) and 390,000 (f, h). The former comparison enables to isolate the effect of coding genome streamlining (g). The latter comparison enables to isolate the effect of non-coding genome expansion (h). The coding genome evolves to be far more neutral, skewing the distribution to the left (g). Non-coding genome expansion cancels most of the former effect and strongly skews the distribution to the right (h). These two effects (g, h) sum up to the right skew observed in (d). All distributions are binned in 7 bins. The first bin contains neutral offspring (Δg=0). Bins 2 through 6 contain the intermediately deleterious offspring binned in 0.002 intervals (Δg from 0.002 to 0.004; 0.004 to 0.006; 0.006 to 0.008 and 0.008 to 0.01). The last bin contains all heavily deleterious offspring (Δg>0.01). See main text and Methods for details

Back to article page