Proctor G N
Plasmid. 1994 Sep;32(2):101-30. doi: 10.1006/plas.1994.1051.
Differential growth of plasmid-containing and plasmid-free microbial cells occurs in many and probably most plasmid systems. Misinterpretation of differential growth as replicational, recombinational, or segregational stability or instability can unfortunately result in grossly erroneous conclusions about replication, recombination, or segregation in plasmid model systems for studies of such phenomena. The differential growth rate should ideally be measured every time that the rate of loss due to instability per se is measured. Unfortunately, the possibility of differential growth has been ignored in most plasmid model systems, since the mathematics of instability and differential growth has not usually been dealt with in ways that are intuitively understandable to experimental microbiologists. Nevertheless, rapid diagnosis of differential growth, and accurate estimation of differential growth rate and rate of loss due to instability per se, can be done by analysis of colony number data using only the relatively simple mathematics described in this review. This review is intended for experimental microbiologists rather than for theoretical population geneticists or for pure mathematicians. However, the same mathematics described in this review is also applicable to certain simple model systems for plasmid ecology or evolution in natural or clinical environments.
在许多甚至可能是大多数质粒系统中，含质粒和不含质粒的微生物细胞会出现差异生长。不幸的是，将差异生长误解为复制、重组或分离稳定性或不稳定性，可能会导致在用于研究此类现象的质粒模型系统中，得出关于复制、重组或分离的严重错误结论。理想情况下，每当测量由于不稳定性本身导致的损失率时，都应该测量差异生长率。不幸的是，在大多数质粒模型系统中，差异生长的可能性被忽视了，因为不稳定性和差异生长的数学通常没有以实验微生物学家直观理解的方式来处理。然而，仅通过使用本综述中描述的相对简单的数学方法分析菌落数量数据，就可以快速诊断差异生长，并准确估计差异生长率和由于不稳定性本身导致的损失率。本综述是针对实验微生物学家，而非理论群体遗传学家或纯数学家。然而，本综述中描述的相同数学方法也适用于自然或临床环境中质粒生态学或进化的某些简单模型系统。
