FATE OF PARENTAL HERPESVIRUS DNA

The fate of the DNA of infecting pseudorabies virions in rabbit kidney cells was followed. The rate of adsorption of infectious and noninfectious virions is the same. Most of the DNA in the adsorbed virions (infectious and noninfectious) in preparations of freshly purified virions is rapidly transferred to the cell nucleus and replicates. Storage of the virions at -70.degree. C does not significantly affect infectivity but does affect the ability of the DNA in some of the adsorbed virions to be transferred to the cell nucleus and to replicate. Although the DNA in the noninfectious particles present in preparations of fresh virions replicates, this process is dependent upon coinfection of the cells with infectious virus, indicating that the replication of the DNA of noninfectious particles requires the expression of some functions of the DNA in infectious particles. Most of the single-stranded interruptions in mature pseudorabies viral DNA are ligated prior to the replication of the DNA. Few double-stranded fragments of viral DNA accumulate in the infected cell. Breakage and reunion of parental viral DNA is detectable and seems to occur preferentially around the middle of the molecules.