Rescue of infectious virus from permissive monkey cells containing simian virus 40 DNA fragments

Permissive TC7 cells were separately transfected with simian virus 40 (SV40) EcoRI/Hap II A (74% genome) DNA fragments and EcoRI/Hap II B (26% genome) DNA fragments in the presence of DEAE-dextran. Fusion of the progeny of recipient cells receiving the A fragment, TC7(SV40/74) cells, with TC7(SV40/26) cells, which had received the B fragment, resulted in SV40 rescue. TC7(SV40/74 + 26) cells, which had simultaneously received both complementary subgenomes, either spontaneously produced SV40 upon subculture or yielded virus upon treatment with iododeoxyuridine. In addition, fusion of rat cells containing the EcoRI/Hap II A fragment with TC7(SV40/26) cells resulted in SV40 rescue. Cytopathology, V-antigen production, neutralization, and electron microscopy were parameters used to verify that the rescued virus was SV40. No infectious virus was produced when the combinations of cells fused did not total a complete SV40 genome equivalent.