Synthesis of Viral DNA in the Cytoplasm of Duck Embryo Fibroblasts and in Enucleated Cells after Infection by Avian Sarcoma Virus

Abstract

TWO LINES OF EVIDENCE INDICATE THAT SYNTHESIS OF VIRAL DNA OCCURS IN THE CYTOPLASM OF DUCK EMBRYO FIBROBLASTS INFECTED WITH AVIAN SARCOMA VIRUS: (i) viral DNA is detected first in the cytoplasmic fraction of infected cells and subsequently in the nuclear fraction; and (ii) viral DNA is synthesized at a normal rate in cells infected after enucleation with cytochalasin B. The presence of viral DNA in the cytoplasmic fraction is not a consequence of leakage of newly synthesized viral DNA from the nucleus, since it remains in nuclear fractions late after infection when integration of viral DNA into the host genome is inhibited by ethidium bromide.