Quantification of influenza virus messenger RNAs

The amounts of specific influenza virus cRNAs present on polyribosomes of cells treated with cycloheximide at various times after infection were measured by quantitative hybridization with 125I-labelled virus RNA segments. All species of cRNA were found associated with polyribosomes at every time point analysed. The relative abundance of the specific RNAs was in the same order as the reported relative synthesis of the influenza virus proteins. However, the concentrations of the cRNAs spanned a considerably smaller range than published protein synthetic rates, suggesting that both transcriptional and translational controls operate to regulate the final levels of influenza virus polypeptide synthesis.