[The role of polymerase protein genes of influenza A virus in the transition from the early to late stage of replication]

Abstract

Regulation of influenza virus RNA replication was studied with the use of A/FPV/Rostock/34 strain ts-mutants. Mutants C44, C15, C45 possessing the ts-defects in the PB2, PB1 and PA genes respectively were used for the infection of chick embryo cultured cells and H-uridine-labelled nucleocapsid-associated RNA was analysed in polyacrylamide gel electrophoresis to assess the kinetics of vRNA synthesis. A typical early-late transition of the pattern of vRNA synthesis was observed in the cells infected with C44, whereas the other two mutants exhibited a slightly changed (C15) or strongly distorted (C45) pattern. In shift up experiments after the transfer to non-permissive temperature all the mutants exhibited partial reversion to an early pattern of vRNA synthesis. The results are discussed in connection with the mechanism of the early-late transition of influenza virus-specific RNA synthesis.