Monitoring recombinant baculovirus replication in Spodoptera litura (Lepidoptera: Noctuidae) larvae by using firefly luciferase gene as a reporter

Abstract

An engineered virus, vAcluc, carrying the firefly luciferase (luc) gene as a reporter was injected into the hemocoel and different regions of the gut of Spodoptera litura F. to study the route of infection and virus dissemination. Luciferase activity was detected at 72 h postinfection in all the tissues examined (i.e., gut, gonads, cuticle, fat body, and the hemolymph). However, at 144 h post-infection expression was restricted primarily to the fat body tissue. Although injection of virus into the hemocoel was the most effective way of inoculation, injection into the gut also resulted in luc expression, albeit at a lower level, suggesting that nonoccluded viruses can also be infected orally.