An Analysis of SV40-Induced Transformation of Hamster Kidney Tissue In Vitro. III. Persistence of SV40 Viral Genome in Clones of Transformed Hamster Cells2

Abstract

Clones of SV40-transformcd hamster kidney cells were established from single cells isolated in microdrop cultures containing SV40 antiserum. Infectious SV40 was recoverable, by the overlay technique, from 11 of 12 clones from positive lines. Clones derived from the negative clone remained negative for SV40 but contained the SV40-specific T antigen in essentially all of the cells, as did the positive clones. No infectious virus or viral antigen was ever found in any of the clone lines, by methods other than the overlay technique, but small amounts of virus were occasionally recovered from hamster tumors induced with cells from positive clones. The results indicate that all the SV40-transformed hamster kidney cells have at least a part of the SV40 genome and that the vast majority contain the complete SV40 genome in the absence of synthesis of whole virus.