Properties of Temperature-sensitive Mutants of the KENYA 3/57 Strain of Foot-and-mouth Disease Virus

Abstract

Summary The physiological defects associated with 17 temperature-sensitive mutants of the kenya 3/57 strain of foot-and-mouth disease virus were examined in terms of the ability of the mutants to produce infective RNA and complementfixing antigen under restrictive conditions. The yields of infective RNA obtained with different mutants ranged from less than 0·31 to 87% of normal, and of complement-fixing antigen from 12·6 to 99·6 % of normal. Genetic recombination was observed in crosses of mutants with different physiological effects, such that the mutants could be arranged in five groups.