Abstract
Influenza virus polypeptides were not synthesized in wild-type CHO-S-infected [Chinese hamster ovary] cells in the presence of .alpha.-amanitine, but were synthesized in CHO-Amal [.alpha.-amanitine resistant] cells, a mutant cell line whose DNA-dependent RNA polymerase II is specifically resistant to this drug, indicating that this cellular enzyme is involved in influenza virus replication. The results of experiments designed to detect viral polypeptides synthesized from primary transcripts suggest that the synthesis of a cellular RNA species by RNA polymerase II is required for primary transcription of the influenza virus genome.