Morris D W, Ogden-Swift S R, Virrankoski-Castrodeza V, Ainley K, Parish J H
J Gen Microbiol. 1978 Jul;107(1):73-83. doi: 10.1099/00221287-107-1-73.
Chloramphenicol-resistant Myxococcus virescens were obtained by infecting myxococci with Escherichia coli specialized transducing phage P1CM. The drug-resistant myxococci were phenotypically unstable. They contained more than one type of plasmid; these plasmids were not found in the parent strain. Chloramphenicol-resistant E. coli were obtained by transformation with either a fraction of myxococcal DNA containing the plasmids or with P1CM prophage DNA. These transformants contained plasmids. Escherichia coli transformed by DNA from the myxococci contained both P1CM and myxococcal genes. Individual transformant clones differed in the genetic make-up of their plasmids. Among the myxococcal genes expressed in these plasmid-harbouring E. coli strains were a capacity for self-transmissibility and a pattern of phage sensitivity characteristic of R factor incompatibility group W. Escherichia coli transformed with P1CM prophage contained incomplete P1CM genomes; none of the chloramphenicol-resistant transformants produced P1CM phage particles. The significance of these findings for an understanding of mechanisms for the generation of R factors is discussed.
通过用大肠杆菌特异性转导噬菌体P1CM感染粘球菌，获得了耐氯霉素的绿色粘球菌。耐药性粘球菌在表型上不稳定。它们含有不止一种类型的质粒；这些质粒在亲本菌株中未被发现。通过用含有这些质粒的部分粘球菌DNA或P1CM原噬菌体DNA进行转化，获得了耐氯霉素的大肠杆菌。这些转化体含有质粒。用粘球菌DNA转化的大肠杆菌同时含有P1CM和粘球菌基因。单个转化体克隆的质粒基因组成不同。在这些含有质粒的大肠杆菌菌株中表达的粘球菌基因包括自我传递能力和R因子不相容群W特有的噬菌体敏感性模式。用P1CM原噬菌体转化的大肠杆菌含有不完整的P1CM基因组；耐氯霉素的转化体均未产生P1CM噬菌体颗粒。讨论了这些发现对于理解R因子产生机制的意义。
