Abstract
Following Newcastle disease virus infection, the synthesis of both cellular RNA and DNA in chick embryo fibroblast monolayers was inhibited. In such monolayers, Newcastle disease virus infection did not significantly reduce the content of cellular DNA within 10 hr, but did reduce the amount of cellular RNA by about 50% in that time. A part of the RNA was degraded into acid-soluble material and leaked out of the cells. Some fraction of the ribosomal RNA gave rise to small molecular weight fragments which sedimented near the transfer RNA region as determined by sucrose density gradient centrifugation. Evidence is presented indicating that virus-induced proteins, which were synthesized by 6 hr after infection, were involved in the RNA degradation process.