[Characteristics of Bacillus thuringiensis phages with circular permutation in the DNA molecule].

Bacteriophages Tm2 and Tg27 of different origins but identical in biological properties have been compared. Physicochemical characteristics of bacteriophages have revealed the existence of end repeats and circular permutation of phage DNA. Phages Tm2 and Tg27 share the same dimensions of incapsulated DNA, differing in the sizes of phage genome and end repeats. Bacteriophage Tm2 genome is 45.2 kb. long with the end repeats containing 5.7%. The genome of Tg27 is 42.53 kb and 11.8% of end repeat. The bacteriophages relation has been confirmed by heteroduplex and restriction analysis. Tm2 and Tg27 share 84% of homology. Two regions of nonhomology are found representing a single-stranded loop and equishouldered vesicle with the sizes 2.19 kb and 5.03 kb, respectively.