Genetic recombination in bacteriophage phi-X 174

RECENTLY, Tessman1,2 and Sinsheimer3 suggested that the deoxyribonucleic acid of ΦX 174 is one-stranded in contrast to the double-stranded deoxyribonucleic acid of other phages. From this point of view it seemed interesting to investigate genetic recombination in this phage. Tessman4 achieved recombination in bacteriophage S 13 by stimulation with ultra-violet irradiation of free virus particles. (S 13 is serologically related to ΦX 174 and similar in other properties.) The frequency of recombinants found after ultra-violet irradiation was of the order of 0.1 per cent. In other work5 without irradiation, no recombination could be detected.