The cost of gene expression underlies a fitness trade-off in yeast

摘要: Natural selection optimizes an organism's genotype within the context of its environment. Adaptations to one environment can decrease fitness in another, revealing evolutionary trade-offs. Here, we show that cost gene expression underlies a trade-off between growth rate and mating efficiency yeast Saccharomyces cerevisiae. During asexual growth, mutations eliminate ability mate provide ≈2% per-generation growth-rate advantage. Some strains, including most laboratory carry allele GPA1 (an upstream component pathway) increases by ≈30% per round at ≈1% disadvantage. In addition demonstrating efficiency, our results illustrate differences selective pressures defining versus natural selection, acting on expression, optimize levels promote loss.