TEMPERATURE-SENSITIVE MUTANTS OF VESICULAR STOMATITIS-VIRUS ARE CONDITIONALLY DEFECTIVE PARTICLES THAT INTERFERE WITH AND ARE RESCUED BY WILD-TYPE VIRUS

Temperature-sensitive (ts) mutants of vesicular stomatitis virus belonging to complementation groups I, II and IV inhibited the replication of wild-type vesicular stomatitis virus when mixed infections were carried out in [baby hamster kidney] BHK-21 cells at 32, 37 and 39.5.degree. C. The group IV mutant (ts G 41) was most effective in this regard; wild-type virus yields were inhibited .apprx. 1000-fold in mixed infections with this mutant at 32.degree. C. In group I and II mutants, inhibition of wild-type virus replication at 37 and 39.5.degree. C was accompanied by an enhancement (.ltoreq. 15,000-fold) of the yields of the coinfecting ts mutant. The yields of the group IV mutant (ts G 41) were not enhanced by mixed infections with wild-type virus at any temperature, although this mutant inhibited wild-type virus replication at all temperatures. The dominance of the replication of ts mutants at 37.degree. C explains the selection and maintenance of ts virus in persistently infected cells.