Environment-independent distribution of mutational effects emerges from microscopic epistasis.

ABSTRACT: Predicting how new mutations alter phenotypes is difficult because mutational effects vary across genotypes and environments. Recently discovered global epistasis, in which the fitness effects of mutations scale with the fitness of the background genotype, can improve predictions, but how the environment modulates this scaling is unknown. We measured the fitness effects of ~100 insertion mutations in 42 strains of Saccharomyces cerevisiae in six laboratory environments and found that the global epistasis scaling is nearly invariant across environments. Instead, the environment tunes one global parameter, the background fitness at which most mutations switch sign. As a consequence, the distribution of mutational effects is predictable across genotypes and environments. Our results su

SUBMITTER: Ardell SM 

PROVIDER: S-EPMC11580693 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature