Reversions mask the contribution of adaptive evolution in microbiomes.

ABSTRACT: When examining bacterial genomes for evidence of past selection, the results obtained depend heavily on the mutational distance between chosen genomes. Even within a bacterial species, genomes separated by larger mutational distances exhibit stronger evidence of purifying selection as assessed by d N / d S , the normalized ratio of nonsynonymous to synonymous mutations. Here, we show that the classical interpretation of this scale-dependence, weak purifying selection, leads to problematic mutation accumulation when applied to available gut microbiome data. We propose an alternative, adaptive reversion model with exactly opposite implications for dynamical intuition and applications of d N / d S . Reversions that occur and sweep within-host populations are nearly guaranteed

SUBMITTER: Torrillo PA 

PROVIDER: S-EPMC10515931 | biostudies-literature | 2024 Jun

REPOSITORIES: biostudies-literature