Genetic analysis of simian virus 40. IV. Inhibited transformation of Balb-3T3 cells by a temperature-sensitive early mutant.

The temperature-sensitive early mutant, ts(*)101, was characterized during productive infection in monkey cells, and the results are presented in an accompanying paper. This paper demonstrates that although 101 mutant virions adsorb normally to confluent Balb/3T3 mouse cells at both permissive (33 C) and restrictive (38.5 C) temperatures, T antigen synthesis and transformation, abortive and stable, are inhibited at both temperatures (host-range inhibition). T antigen synthesis is temperature sensitive, whereas abortive and stable transformation are not. Clones of 101-transformed Balb/3T3 cells were isolated, and virus was rescued from all clones at both permissive and restrictive temperatures. The rescued virus was as temperature sensitive as the original transforming 101 virions.