Analysis of simian virus 40-induced transformation of hamster kidney tissue in vitro. V. Variability of virus recovery from cell clones inducible with mitomycin C and cell fusion.

Clones of simian virus 40-transformed hamster kidney cells from which infectious virus could be recovered and clones which did not yield virus by the overlay technique were subjected to chemical (mitomycin C) induction and to co-cultivation and fusion studies with indicator cells. The results of these studies indicate that the complete viral genome is present in all clones tested but that considerable heterogeneity with respect to inducibility exists among the clones. It is suggested that differences either in the number of viral genomes per transformed cell or in the status of the viral genome in transformed cells exist among the various clones. Furthermore, the inducibility of the clones may be correlated with their malignant potential.