Levy S B
J Bacteriol. 1971 Oct;108(1):300-8. doi: 10.1128/jb.108.1.300-308.1971.
Both fi(+) and fi(-) type R factors function as intact replicative units when segregated into Escherichia coli minicells. Hybridization studies demonstrate that at least 95% of the deoxyribonucleic acid (DNA) in R(+) minicells is episomal in origin. About half of the DNA can be extracted in a closed circular form and about 75% of the DNA is membrane associated. DNA, ribonucleic acid, and protein synthesis proceeds in R(+) minicells in contrast to R(-) minicell controls. The system offers a unique opportunity to study a relatively small replicative unit in a native cell environment and a simple means of isolating large quantities of episomal DNA.
当F⁺和F⁻型R因子被分离到大肠杆菌微小细胞中时，它们都作为完整的复制单位发挥作用。杂交研究表明，R⁺微小细胞中至少95%的脱氧核糖核酸（DNA）起源于附加体。大约一半的DNA可以以闭环形式提取，并且大约75%的DNA与膜相关。与R⁻微小细胞对照相比，R⁺微小细胞中DNA、核糖核酸和蛋白质合成均能进行。该系统为在天然细胞环境中研究相对较小的复制单位提供了独特的机会，也是分离大量附加体DNA的简单方法。
