Nucleo-cytoplasmic studies in the development of influenza virus in mammalian cells

Abstract

A non-ionic detergent method of cell fractionation was used to follow the time course of tritiated uridine incorporation into influenza A-NWS virus-induced RNA in a continuous mammalian cell line. The maximum incorporation of tritiated uridine into acid-insoluble RNA of nuclear fractions occurred at 2 to 2.5 hours post infection. A maximum of labelled acid-insoluble RNA of the cytoplasmic fractions was found at 3 to 4 hours post infection which coincided with active synthesis of infectious virus. The effect of influenza A-NWS infection on the rate of tritiated thymidine incorporation into acid-insoluble DNA was found to be an initial depression 1 to 2 hours post infection followed by recovery to near normal values, then a gradual decline until at 8 hours post infection it was approximately 60% of that shown by the control cell cultures.