Requirement for cell division for initiation of transcription of Rous sarcoma virus RNA.

Stationary chicken embryo fibroblasts exposed to Rous sarcoma virus (RSV) did not synthesize virus RNA until after division of the infected cells. Initiation of RNA transcription after cell division resulted in transcription of the entire viral genome and was followed shortly thereafter by appearance of progeny virus. Addition of colchicine to RSV-infected stationary chicken embryo fibroblasts resulted in inhibition of cell division and a 24-h delay in the appearance of virus RNA. RSV-infected chicken embryo fibroblasts made stationary 10 to 15 cell generations after infection continued to produce an amount of progeny virus similar to that produced in dividing RSV-infected cells. Teh virus produced from cells made stationary after virus production had begun contained RNA synthesized in stationary cells. Therefore, division of the RSV-infected chicken embryo fibroblast is required for the initiation of transcription of virus RNA, but it is not required for the maintenance of transcription of virus RNA.