York M K, Stodolsky M
Mol Gen Genet. 1981;181(2):230-40. doi: 10.1007/BF00268431.
Specialized transducing derivatives of the temperate bacteriophage P1 (P1std) are selected by transduction into recipients with deletions in the corresponding genes (Stodolsky 1973). When Escherichia coli K12 strains are used as donors in such transduction experiments, P1argF derivatives can be selected. The argF gene is unique to these strains (Glansdorff et al. 1967). Under these experimental conditions P1argF are formed with frequencies 10,000 times greater than other P1std. The majority of the P1argF derivatives that have been analyzed are indistinguishable by cleavage analyses. One such derivative, P1argF5 has been characterized in detail. Heteroduplex analysis against P1, P7, and P1CmO identified an 11 kb insertion of DNA precisely at the naturally occurring IS1 locus of P1. Cleavage analysis with EcoRI, BamHI and PstI confirmed this finding. To further define the argF insertion, a P1Cm13argF derivative was constructed having the IS1 sequences of Cm13 and argF in opposite orientation. Intrastrand annealing of P1Cm13argF5 DNA established that the argF segment is flanked by directly repeated IS1 sequences. The IS1-argF-IS1 segment is designated Tn2901. The assignment of the map position of the argF gene within the 11 kb insert of P1argF5 is discussed. The evolutionary significance of this finding and a model for P1argF formation is also presented.
温和噬菌体P1的特异性转导衍生物（P1std）是通过转导到相应基因有缺失的受体菌中筛选出来的（斯托多尔斯基，1973年）。当在这种转导实验中使用大肠杆菌K12菌株作为供体时，可以筛选出P1argF衍生物。argF基因是这些菌株所特有的（格兰斯多夫等人，1967年）。在这些实验条件下，P1argF的形成频率比其他P1std高10000倍。大多数经过分析的P1argF衍生物通过切割分析无法区分。其中一种衍生物P1argF5已被详细表征。针对P1、P7和P1CmO的异源双链分析确定，在P1的天然IS1位点精确插入了一段11 kb的DNA。用EcoRI、BamHI和PstI进行的切割分析证实了这一发现。为了进一步确定argF插入片段，构建了一种P1Cm13argF衍生物，其Cm13和argF的IS1序列方向相反。P1Cm13argF5 DNA的链内退火表明，argF片段两侧是直接重复的IS1序列。IS1-argF-IS1片段被命名为Tn2901。讨论了argF基因在P1argF5的11 kb插入片段中的图谱位置分配。还介绍了这一发现的进化意义以及P1argF形成的模型。
