Abstract
Chick embryo fibroblasts (CEF) infected with virulent strains of Newcastle disease virus (NDV) showed a dramatic increase in total unsaturated fatty acids (UFA). This increase was not seen in cells infected with the avirulent strains of NDV, Sendai virus or influenza A (PR8). The virions of the virulent strains of NDV harvested from the chorioallantoic cavity also had a higher UFA content compared to the avirulent ones. The kinetics of UFA increase in the virulent strains was correlated with data on the kinetics of RNA and protein synthesis inhibition, polykaryon formation and membrane permeability changes.