Ultrastructural studies on the replication of herpes virus ateles-73 in owl monkey kidney cells

The replicative cycle of herpesvirus ateles, strain 73 (HVA-73), was examined in the electron microscope and compared to that of other herpesviruses known to be oncogenic. A relatively slow replicative cycle of HVA-73 in owl monkey kidney (OMK) cells allowed us to distinguish cytoplasmic and nuclear stages of replication, comprising virus uptake, transport, maturation, and extrusion. Virus uptake was observed within 10 hours of infection and occurred both as a result of fusion between virus and cell membranes and by phagocytosis. Morphologic evidence for the transfer of viral DNA from nuclecapsids to the nucleus at the nuclear membrane is presented. This is shown by the location of numerous empty capsids in front of nuclear pores early during infection. Towards the end of the eclipse phase, at about 48 hougs after infection, two different types of nuclear inclusion bodies were observed. Progeny nucleocapsids were detected in the nucleus at the same time. The envelopment of nucleocapsids occurred both at the nuclear membrane and at proliferating Golgi lamellae in the cytoplasm. Each site of envelopment is associated with the maturation of a characteristic, morphologically distinguishable virus particle. The assembly of HVA-73 resembled that of other oncogenic herpesviruses.