Feiss M, Adyha S, Court D L
Genetics. 1972 Jun;71(2):189-206. doi: 10.1093/genetics/71.2.189.
Plaque-forming, galactose-transducing lambda strains have been isolated from lysogens in which bacterial genes have been removed from between the galactose operon and the prophage by deletion mutation.-A second class has been isolated starting with a lysogenic strain which carries a deletion of the genes to the right of the galactose operon and part of the prophage. This strain was lysogenized with a second lambda phage to yield a lysogen from which galactose-transducing, plaque-forming phages were obtained. These plaque-forming phages were found to be genetically unstable, due to a duplication of part of the lambda chromosome. The genetic instability of these partial diploid strains is due to homologous genetic recombindation between the two identical copies of the phage DNA comprising the duplication. The galactose operon and the duplication of phage DNA carried by these strains is located between the phage lambda P and Q genes.
已从溶源菌中分离出形成噬菌斑、转导半乳糖的λ菌株，在这些溶源菌中，通过缺失突变已从半乳糖操纵子和原噬菌体之间去除了细菌基因。第二类菌株是从一个溶源菌株开始分离得到的，该溶源菌株携带半乳糖操纵子右侧基因和部分原噬菌体的缺失。用第二种λ噬菌体使该菌株溶源化，产生一个溶源菌，从中获得转导半乳糖、形成噬菌斑的噬菌体。由于λ染色体部分重复，发现这些形成噬菌斑的噬菌体在遗传上不稳定。这些部分二倍体菌株的遗传不稳定性是由于构成重复的噬菌体DNA的两个相同拷贝之间的同源基因重组。这些菌株携带的半乳糖操纵子和噬菌体DNA重复位于噬菌体λ P基因和Q基因之间。
