Electron Microscopic Observations on the Rescue of SV40 Virus From Transformed Cells

Abstract

Several laboratories have reported that simian virus 40 (SV40) was rescued from transformed cells when the nonproducing cells were cocultivated or fused in the presence of ultraviolet inactivated Sendai virus (UV-SV), to potentially susceptible cells. Evidence obtained from studies in which nuclei from heterokaryons were isolated and separated on density gradients, indicated that rescued virus was first detected in the transformed nuclei of the heterokaryons formed during cell fusion. The present study was performed to determine how long after fusion SV40 virus particles could be found in the nuclei of the heterokaryons and to investigate the site of rescue by electron microscopy.