Abstract
A new set of hybrid viruses has been isolated whose closed circular genomes 5 to 6 kB in size, contain DNA sequences derived in part from adenovirus 2 and in part from SV40. The structure of these genomes is complex, but in the simplest case, analyses by restriction endonuclease digestion and hybridization indicate that the adenovirus 2 DNA is present as a continuous block, of maximum size 2.8 kB. Different hybrids contain sequences derived from different segments of the adenovirus 2 genome.