Capaldo F N, Ramsey G, Barbour S D
J Bacteriol. 1974 Apr;118(1):242-9. doi: 10.1128/jb.118.1.242-249.1974.
Cultures of recombination-deficient strains of Escherichia coli are composed of three classes of cells: (i) viable cells, which can undergo 20 or more generations, (ii) residually dividing cells, which can undergo fewer than 20 generations (probably an average of fewer than 6), and (iii) nondividing cells, which are incapable of a single division. The nonviable but residually dividing cells contribute to the mass increase of the culture, but not to the viability, thus accounting for the apparent dissimilarity in the effects of rec mutations on growth rates and viabilities. We have determined the frequencies of cells in each of the three classes, and, by making a simplifying assumption concerning the relative division times of viable and residually dividing cells, we have been able to describe mathematically the growth of the rec(-) cultures.
（i）活细胞，可经历20代或更多代；（ii）残留分裂细胞，可经历少于20代（可能平均少于6代）；（iii）非分裂细胞，不能进行一次分裂。无活力但仍能分裂的细胞有助于培养物的质量增加，但对活力无贡献，因此解释了rec突变对生长速率和活力影响的明显差异。我们已经确定了这三类细胞中每一类的频率，并且通过对活细胞和残留分裂细胞的相对分裂时间做出一个简化假设，我们能够从数学上描述rec（-）培养物的生长情况。
