Temperature-sensitive mutants of Balb/3T3 cells: Description of a mutant affected in cellular and polyoma virus DNA synthesis

Abstract

A temperature-sensitive Dna— mutant (ts-2) of the mouse cell Balb/3T3 is characterized. Studies with synchronized cells indicate that the defect is in DNA synthesis itself, rather than in progress toward its initiation. ts-2 supports polyoma DNA synthesis after infection at 33°C but not at 38°C. Viral DNA synthesis begun at 33°C is inhibited upon shift to 38°C. A procedure is proposed by which viral DNA synthesis can be used to distinguish different classes of cell Dna— mutants.