Effects of canavanine treatment on herpesvirus morphogenesis in cultured cells

L-Canavanine, a naturally occurring analog of arginine, effectively inhibited the morphogenesis of herpes simplex virus (HSV) and human cytomegalovirus (HCMV) when added at the time of infection, but allowed the expression of several cytopathic changes. Exposure to canavanine at progressively later times ultimately led to qualitatively normal virion maturation. Under no conditions were morphologically aberrant viral particles observed. However, HSV-infected cells treated at 3 h postinfection or later did contain distinctive cytoplasmic inclusions resembling HCMV dense bodies. Recovery experiments showed that HCMV-infected cells exposed to canavanine for 1-5 days could support normal viral morphogenesis when washed free of this agent.