Propagation in E. coli of bacteriophage lambda with integrated fragments of adenovirus 2 DNA.

Hybrid genomes of bacteriophage lambda with integrated fragments of adenovirus type 2 (Ad2) DNA have been constructed in vitro and propagated in E. coli. DNA from a derivative of bacteriophage lambdaplac5 (Rambach and Tiollais, 1974) was used as a vector. The two fragments of the vector DNA contain all the essential genes for the replication of the lambda DNA but are too short to be encapsidated. Insertion of DNA is therefore essential for plaque formation which constitutes a selection method for phages containing hybrid genomes. Fragments EcoRI-B and EcoRI-F of Ad2 DNA were purified, and separately ligated with the vector fragments. Clones of hybrid phage could readily be isolated. Two clones of hybrid phage containing fragment EcoRI-B inserted in opposite directions were used to study the transcription of adenovirus-specific sequences. Hybridization experiments showed that transcripts from both strands of fragment Ad2-Eco RI-B could be detected and that transcription probably was controlled by the "early" leftward and the "late" rightward promoters on the lambda genome. No polypeptides specified by the adenovirus fragment have so far been identified.