MacFarren A C, Clowes R C
J Bacteriol. 1967 Aug;94(2):365-77. doi: 10.1128/jb.94.2.365-377.1967.
Of three colicin factors, each determining the synthesis of a colicin V in three wild-type Escherichia coli strains studied, two were shown to have sex-factor activities. In E. coli K-12, these activities resembled those of the F sex factor (including rapid and efficient self-transmission in exponentially growing cultures, adsorption of "male-specific" ribonucleic acid phage, production of "female phenocopies," elimination by acridine orange, and chromosomal transfer dependent upon recombination with host bacterium) and differed in this way from those of the colicin I sex factor (ColI). The two V factors, ColV2 and ColV3, differed in their efficiency of plating male-specific phage and in the pattern of transfer of chromosomal markers. Furthermore, although neither factor could stably coexist with F within the same cell, they showed markedly different exclusion effects. In general, ColV2 excluded F and ColV3 was excluded by F, irrespective of which sex factor was preestablished in the cell. An exception to this was the ability of ColV2 to stabilize in any one of a series of Hfr strains, giving rise to strains which in the majority of cases showed normal Hfr and colicinogenic properties.
在研究的三种野生型大肠杆菌菌株中，每种菌株都由三种大肠杆菌素因子之一决定大肠杆菌素V的合成，其中两种显示出具有性因子活性。在大肠杆菌K-12中，这些活性类似于F性因子的活性（包括在指数生长培养物中的快速高效自我传递、“雄性特异性”核糖核酸噬菌体的吸附、“雌性表型模拟物”的产生、吖啶橙消除以及依赖于与宿主细菌重组的染色体转移），并以这种方式与大肠杆菌素I性因子（ColI）的活性不同。这两种V因子，ColV2和ColV3，在雄性特异性噬菌体的铺板效率和染色体标记的转移模式上有所不同。此外，尽管这两种因子都不能与F在同一细胞内稳定共存，但它们显示出明显不同的排斥效应。一般来说，ColV2排斥F，而ColV3被F排斥，无论细胞中预先存在哪种性因子。一个例外是ColV2能够在一系列高频重组（Hfr）菌株中的任何一种中稳定存在，从而产生在大多数情况下显示出正常Hfr和产大肠杆菌素特性的菌株。
