Ninio J
Institut Jacques Monod, Paris, France.
Genetics. 1991 Nov;129(3):957-62. doi: 10.1093/genetics/129.3.957.
A population of bacteria growing in a nonlimiting medium includes mutator bacteria and transient mutators defined as wild-type bacteria which, due to occasional transcription or translation errors, display a mutator phenotype. A semiquantitative theoretical analysis of the steady-state composition of an Escherichia coli population suggests that true strong genotypic mutators produce about 3 x 10(-3) of the single mutations arising in the population, while transient mutators produce at least 10% of the single mutations and more than 95% of the simultaneous double mutations. Numbers of mismatch repair proteins inherited by the offspring, proportions of lethal mutations and mortality rates are among the main parameters that influence the steady-state composition of the population. These results have implications for the experimental manipulation of mutation rates and the evolutionary fixation of frequent but nearly neutral mutations (e.g., synonymous codon substitutions).
在非限制性培养基中生长的细菌群体包括突变细菌和瞬时突变体，瞬时突变体被定义为野生型细菌，由于偶尔的转录或翻译错误而表现出突变表型。对大肠杆菌群体稳态组成的半定量理论分析表明，真正的强基因型突变体产生群体中出现的单突变的约3×10⁻³，而瞬时突变体产生至少10%的单突变和超过95%的同时发生的双突变。后代继承的错配修复蛋白数量、致死突变比例和死亡率是影响群体稳态组成的主要参数。这些结果对突变率的实验操作以及频繁但近乎中性的突变（例如同义密码子替换）的进化固定具有启示意义。
