RNA synthesis in standard and autointerfered vesicular stomatitis virus infections.

The levels of intracellular viral RNA have been measured in BHK-21 cells undergoing standard and autointerfered infections with vesicular stomatitis virus (VSV). The total amount of intracellular nucleocapsid RNA is almost unaffected by autointerference. However, the composition of this class of RNA changes with increasing autointerference: Control cells undergoing standard infections contain only the 140 S, full genomic length nucleocapsid, while autointerfered cells contain, in addition, a smaller nucleocapsid which corresponds in size to that found in the defective interfering (DI) particle. There is a systematic decrease in viral mRNA with increasing autointerference. This decrease in mRNA closely parallels the reduced yield of total progeny particles eventually released from these cells. A causal relationship between the two is proposed. These results are compatible with explanations of autointerference that depend upon a competition between the DI and VSV genomes for the viral replicase.