Genetic recombination of bacteriophage T7 DNA in Vitro IV. Asymmetry of recombination frequencies caused by polarity of DNA packaging in Vitro

Recombination frequencies of phage T7 DNA measured using an in vitro assay for genetic recombination and DNA packaging (Sadowski and Vetter, 1976) show a marked asymmetry. This asymmetry was shown to be caused by polar packaging of the DNA during the reaction rather than asymmetry of recombination itself. Recombinant T7 DNA, formed during a physical assay for in vitro T7 recombination (Vlachopoulou and Sadowski, 1977), was shown to be genetically recombinant using a highly efficient assay for packaging of T7 DNA in the absence of recombination.