Novick R P
Mol Gen Genet. 1974;135(2):131-47. doi: 10.1007/BF00264781.
Some 85 Staphylococcus aureus mutants phenotypically thermosensitive for penicillinase plasmid segregation (Seg-) have been isolated and characterized. Some of the mutations were plasmid-linked and those studied in detail were found to be defective in plasmid replication, most problbly at the initiation stage. Analysis of the segregation behavior of these mutants suggested a figure of 2.7 for the average number of plasmid copies per cell in a random culture. Other mutations were host chromosome-linked and these could be divided into at least three classes on the basis of their ability to maintain plasmids of the two different incompatibility sets: some were defective for type I plasmids, some for type II, and some for both types. One host mutant, defective in segregation of type I but not type II plasmids, was defective in polymerization of both.
已分离并鉴定出约85株对青霉素酶质粒分离表现出温度敏感表型（Seg-）的金黄色葡萄球菌突变体。其中一些突变与质粒相关，经详细研究发现这些突变体在质粒复制方面存在缺陷，很可能是在起始阶段。对这些突变体分离行为的分析表明，在随机培养中每个细胞的质粒平均拷贝数为2.7。其他突变与宿主染色体相关，根据它们维持两种不同不相容组质粒的能力，这些突变可至少分为三类：一些对I型质粒有缺陷，一些对II型质粒有缺陷，还有一些对两种类型质粒都有缺陷。一个宿主突变体，在I型质粒分离方面有缺陷，但II型质粒分离无缺陷，在两者的聚合方面均有缺陷。
