Murine gammaherpesvirus 68 open reading frame 11 encodes a nonessential virion component

Open reading frame 11 (ORF11) is a conserved gammaherpesvirus gene that remains undefined. We identified the product of murine gammaherpesvirus 68 (MHV-68) ORF11, p43, as a virion component with a predominantly perinuclear distribution in infected cells. MHV-68 lacking p43 grew normally in vitro but showed reduced lytic replication in vivo and a delay in seeding to the spleen. Subsequent latency amplification was normal. Thus, MHV-68 ORF11 encoded a virion component that was important for in vivo lytic replication but dispensable for the establishment of latency.