TEMPERATURE-SENSITIVE MUTANTS OF POLYOMA VIRUS

In an attempt to answer the basic question whether polyoma-induced cell transformation is the consequence of the persistent expression of a viral function in the transformed cell, a number of ts mutants of polyoma virus have been isolated and subjected to a genetic analysis. Complementation data suggest that there are at least 4 complementation groups (genes). The first group corresponds to a gene involved in the synthesis of viral DNA. The mutants belonging to this group of complementation were found to be temperature sensitive for transformation. However, cells transformed by these mutants at the permissive temperature did not revert to normal when shifted to the nonpermissive temperature. The second and third groups correspond to genes carrying information for viral proteins. © 1969.