Studies on characterization of the integration sites of avian RNA tumor virus-specific DNA

A sequential hybridization procedure is described which allows the integration sites of viral-specific DNA to be characterized according to their reassociation kinetics. In addition, this approach enables us to estimate the size of the integrated viral DNA. Endogenous virus sequences in normal cells appear to be associated with cell sequences reiterated 1200 times, and each integration unit is approximately equal to one 35S RNA subunit. In AMV-infected cells, the additional AMV-specific DNA sequences reassociate as if they were integrated adjacent to unique cellular DNA or in tandem with the endogenous viral DNA sequences.