[Isolation and characteristics of UV-resistant revertants of recA-strains of Escherichia coli K-12].

The paper presents the results of a study of UV-resistant revertants of some recA strains induced by different mutagens. It is shown that some of produced revertants differ from original recA strains in some properties. It is established that all UV-resistant revertant fall into three phenotypic groups on their recombination proficiency in crosses with different donor strains (Hfr C, Hfr 3.0SO, F' W1655) and in their sensitivity to UV and gamma-rays. It is concluded that all UVr revertants are rec A+ and carried mutations either in the same recA gene (true reversion or intragenic suppression) or in genes closely linked with recA.