GENETIC FACTORS INFLUENCING C-TYPE RNA VIRUS INDUCTION

Genetic factors were studied which affect the inducibility of C-type RNA viruses from embyro cultures of mouse strains with high and low incidence of spontaneous leukemia. Virus was inducible by chemical treatment from secondary embryo cultures of several inbred strains. Both virus inducibility and the capacity of the virus to persist in cells from which it was activated were found to be inherited as dominant genetic characteristics. The results show that the factors controlling virus activation and persistence in culture also play an important role in spontaneous virus expression in the animal.