Evidence for the nonparticipation of DNA in viral RNA synthesis

Abstract

The question whether a DNA intermediate is a prerequisite to the replication of the RNA of animal viruses has been considered. Two methods were used to investigate this problem. In the first, aminopterin and 5-fluorouracil were used to stop DNA synthesis in Hela cells. In the second, 5-bromouracil was incorporated into the DNA of the cells, thus ensuring that any DNA made during the growth of the virus was abnormal. Neither of these treatments affected the yield, or latent period of the RNA-containing poliovirus or Newcastle disease virus. Both treatments markedly reduced the yield of the DNA-containing vaccinia virus. It is suggested that no interaction with DNA is necessary for the growth of the RNA-containing viruses.