Properties of Myxoma Virus Transforming Agent

Abstract

Various methods have been used to define some of the properties of the myxoma virus transforming agent (TAM) which will transform fibroma virus in tissue culture. Myxoma virus can be completely inactivated as far as infectivity is concerned either by heating or by exposure to ether. It will transform fibroma virus after either or both of these treatments. This transforming activity is not destroyed by exposure to desoxyribonuclease (DNase) or to trypsin. It is destroyed by UV light as well as by visible light in the presence of a photodynamic dye, toluidine blue O. TAM particles are approximately the size of untreated myxoma virus. Evidence is given that these particles are taken up by tissue culture cells in the absence of live fibroma virus and are not destroyed by incubation at 36[degree]C. A final discussion considers the possible role of the DNA of myxoma virus and of the action of live fibroma virus in promoting the Berry-Dedrick phenomenon.