[Genetic function of the multiploid virions of alphaviruses].

The natural process of infection with multiploid virions of alphaviruses was modeled by inoculation of cells with artificially obtained aggregates. After infection with the aggregates the progeny of attenuated clones of Venezuelan equine encephalomyelitis virus was found to have some new properties. The virus produced larger plaques and had higher reproduction activity. In some cases, changes in the electrophoretic mobility of virion structural proteins was observed, especially a decrease in the molecular weight of the most conservative of them, C-protein. These properties were retained in passages of the virus in cell cultures. The observed phenomenon is associated with genetic interaction between defective virus genomes getting into cells as the aggregate component. Formation of multiploid virions and infection with these particles are considered as the process providing for retention of the biological properties of the virus under conditions of accumulation of DI-particles in the population.