Yeast mutation rates in alternative carbon sources reflect the influence of reactive oxygen species

TL;DR

This study shows that yeast mutation rates vary with carbon sources, likely due to reactive oxygen species from respiration.

Contribution

The study reveals a nonlinear relationship between respiration rates and mutation rates in yeast under different carbon sources.

Findings

Mutation rates in yeast are highest in pyruvate and lowest in glucose media.

Respiration rates only partially predict mutation rates, indicating complex interactions.

Aerobic respiration produces reactive oxygen species that may influence mutation rates.

Abstract

Environmental conditions can influence mutation rates, but the reasons are often unclear. Budding yeast can utilize many carbon sources, with variation in the degree of fermentation versus respiration. Since aerobic respiration produces mutagenic reactive oxygen species, we hypothesized that yeast grown in media promoting aerobic respiration would show higher mutation rates. We found significant differences across five media types, with the highest mutation rate in pyruvate and the lowest in glucose. However, mutation rates responded to respiration rate in a nonlinear fashion, suggesting that the degree of respiration in a given environment is only partly predictive of mutation rate.

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