EFFECT OF INCUBATION-TIME ON THE GENERATION OF DEFECTIVE-INTERFERING PARTICLES DURING UNDILUTED SERIAL PASSAGE OF SINDBIS VIRUS IN AEDES-ALBOPICTUS AND CHICK-CELLS

Increasing the length of the incubation period enhances the generation of Sindbis virus (SV) defective-interfering (DI) particles and other genetic variants in chick embryo fibroblast (CEF) cells. SV DI particles were also generated by serial undiluted passage in Aedes albopictus (mosquito) cells at 48-hr intervals. The cyclic variation in SV titer characteristic of DI particles began in passage 5. The presence of DI particles in certain virus stocks was confirmed by demonstrating that virus from these passages interfered with the replication of plaque-purified virus and caused the appearance of abnormally small intracellular, SV-specified RNAs. SV DIs generated in A. albopictus cells did not interfere with the replication of SV in chick cells, nor did SV DIs generated in chick cells interfere in A. albopictus cells. In addition to DI particles, certain of the serially passaged Sindbis virus stocks contained temperature-sensitive (ts) and small and medium plaque variants. © 1979.