The integrated SV40 genome in permissive transformed monkey cells

Abstract

The organization of the viral DNA sequences in three clonal lines of SV40-transformed permissive African Green monkey kidney cells was investigated by digesting the cellular DNA with restriction endonucleases and hybridizing the specific DNA fragments with labeled SV40 DNA. The genome of each transformed line contained a single insert of viral sequences located at a position which differed from line to line. No evidence for extrachromosomal SV40 DNA was obtained. Restriction mapping of the inserted SV40 DNA indicated that integration occurred without gross tandem duplication and that an intact early region was retained. Alterations were observed in the late region of the SV40 inserts. Although these alterations were not identical in the three transformed clonal populations, the HaeII restriction endonuclease recognition site at 0.83 SV40 map unit was absent in two of the three lines.