Data from: Mutational effects depend on ploidy level: all else is not equal

Ploidy is predicted to influence adaptation directly, yet whether single mutations behave the same in different ploidy backgrounds has not been well studied. It has often been assumed theoretically that aside from dominance, selective parameters do not differ between cells of varying ploidy. Using the budding yeast Saccharomyces cerevisiae, I compared the effect size of 20 adaptive mutations in haploids and homozygous diploids and found, surprisingly, that the same mutations often had a much larger effect in haploids than homozygous diploids. This empirical result demonstrates that it cannot be assumed that mutations will have the same effect in haploids and homozygous diploids.

倍性（Ploidy）被认为可直接影响生物适应性，但单突变在不同倍性背景下的表现是否一致尚未得到充分研究。理论层面通常假设，除显性效应外，不同倍性细胞的选择参数不存在差异。本研究以出芽酵母酿酒酵母（Saccharomyces cerevisiae）为实验对象，比较了20个适应性突变在单倍体与纯合二倍体中的效应量，意外发现相同突变在单倍体中的效应通常远大于纯合二倍体。这一实证结果表明，无法默认突变在单倍体与纯合二倍体中的效应保持一致。