Abstract
Seventeen temperature-sensitive mutants of equine arteritis virus, a nonarthropod-borne togavirus, have been isolated. 5-Fluorouracil, 0-methylhydroxylamine and ethyl methanesulphonate were used as mutagens. The mutants were characterized by their ability to synthesize virus RNA and virus proteins at the permissive (35 °C) and restrictive temperature (40 °C) using autoradiography of cells labelled with 3H-uridine in the presence of actinomycin D and immunofluorescence respectively. Among the mutants, four were unable to synthesize virus RNA and virus proteins at 40 °C (RNA-/protein-). The other mutants were RNA-/protein+ (3); RNA±/protein- (2); RNA+/protein+ (6) and RNA+/protein- (1).