Equal Transfer of both Parental T7 DNA Strands to Progeny Bacteriophage

Abstract

THE extent of transfer of parental DNA to progeny phage has been the subject of a number of studies^1–8. These investigations have shown that approximately half the parental DNA (isotopically labelled) can be found among the progeny phage. In addition, certain experiments have suggested that, at least in the case of T4 phage, only one of the two DNA strands transmits the genetic information to the progeny virus^9,10. In the case of T7 phage, however, the available data in the literature suggest that significantly less than 50 per cent of the parental DNA is transmitted to the progeny. Mackal and Kozloff² reported, for various experiments, 32, 18, 12 and 9 per cent transmission of parental label to progeny. Recently, Miller5 reported 26 per cent transfer. For the closely related bacteriophage T3, Watson and Maaløe³ reported 46, 38, 38, 38 and 32 per cent of the parental DNA label transferred to the progeny in five separate experiments.