DETECTION AND CHARACTERIZATION OF AN INDUCED RNA POLYMERASE IN CHORIOALLANTOIC MEMBRANES OF EMBRYONATED EGGS INFECTED WITH INFLUENZA A2 VIRUS

An induced RNA polymerase was identified in the microsome fraction of the chorioallantoic membranes of embryonated eggs infected with an influenza A2 virus. The activity of the polymerase, as measured by the incorporation of GMP-3H into RNA from GTP-3H, reached a maximum at 6-8 hours post inoculation and was about 10-fold greater than the corresponding incorporation of the microsome fraction of uninfected membranes. The polymerase was dependent upon the presence of Mg2+ ions and all four ribonucleoside triphosphates for maximum activity and was not inhibited by DNase or actinomycin D. The RNA synthesized in vitro by the polymerase was shown to be a heteropolymer and to contain high molecular weight species sedimenting at 19 S and 14 S. These RNA species were similar in both sedimentation properties and nucleotide composition to the major RNA species extracted from the intact virus. The influenza A2-induced RNA polymerase and its RNA product are discussed in relation to the function of the enzyme in the replication of influenza viruses. © 1969.