Ribonucleic acid synthesis in chick embryo cells infected with fowl-plague virus.

Increases in ribonucleic acid (RNA) polymerase activity were detected in both the nuclear and ribosomal fractions of chick embryo cells infected with fowl-plague virus. These were observed only in the presence of all four nucleoside triphosphates and were not affected by actinomycin D. The RNA polymerase activity of the ribosomal fraction was shown to be associated with a component of infected cells of sedimentation coefficient approximately 70S. This component also contained infected cell-specific RNA and protein molecules.