Method for determining the extent and copy number of overlapping and nonoverlapping segments of integrated viral...

We analyzed the method of exhaustive hybridization of single-stranded DNA and derived a general relationship between the fraction of the probe DNA hybridized and the sizes and copy numbers of the segments of the viral genome integrated in cellular DNA. The equations employed can be used to analyze integrated DNA comprised of overlapping and nonoverlapping segments of the viral genome. Using these equations, we analyzd the adenovirus type 2 DNA content of a series of hamster cell lines transformed by adenovirus type 2 and several adenovirus type 2-simian virus 40 hybrid viruses. We found no eividence that the integrated viral DNA is comprised of overlapsping segments. However, the number of copies of the integrated segments varies between lines cloned from the same transformed isolate, and copy numbers change during in vivo passage of transformed cells.