Kinetics of Viral Transcription after Induction of Prophage

Abstract

Many efforts have been devoted to the study of λ transcription. Since λ does not shut off host functions, DNA-RNA hybridization has proved to be the only technique that permits discrimination between labeled phage and host RNAs.

The accuracy of the information obtained by DNA-RNA hybridization depends on the extent to which the two components of the reaction are specified. The possibility of fractionating DNA, especially halves (Hershey et al., 1965) and strands (Hradecna and Szybalski, 1967) (Fig. 1), and the availability of various deletions, have made DNA-RNA hybridization a powerful tool. The RNAs synthesized by phage mutants can be isolated at various phases of phage growth, and can be shown to belong to different classes. The picture of phage development so obtained agrees well with genetic data (Sly et al., 1965; Isaacs et al., 1965; Skalka, 1966; Cohen and Hurwitz, 1968; Takeda and Yura, 1968; Tonegawa and Hayashi, 1968; Bøvre and Szybalski, 1969; Kumar et al., 1969; Szybalski et al., 1969; McMacken et al., 1970; Kumar and Szybalski, 1970; Nijkamp et al., 1970; Kumar et al., 1970; Heinemann and Spiegelman, 1970; for reviews, see Dove 1968; Echols and Joyner, 1968; Radding, 1969; Calendar, 1970).

Lambda RNA has been fractionated on the basis of sedimentation and electrophoretic properties (Kourilsky and Luzzati, 1967; Kourilsky et al., 1968; Gros et al., 1969; Oda et al., 1969; Kourilsky et al., 1969 and 1970a; Marcaud et al., 1971). The identified species were designated l₀, l₁, l₂, l₃, and r₁, r₂, r₃, r₄ (Fig. 11).