38th Annual Meeting of the Society for Invertebrate Pathology

Over the past 50 years the eastern spruce budworm, Choristoneura fumiferana, has been the most destructive forest insect pest in North America. Management of such pests has relied heavily upon the use of chemical pesticides which tend to harm both non-target and target organisms. Recently, the focus of research has shifted to the use of biological control agents such as the baculovirus C. fumiferana multiple nucleopolyhedrovirus (CfMNPV). Baculoviruses encode five major immediate early transcripts corresponding to ie1, ie-0, ie-2, pe38 and me53. Four of these, ie-1, ie-2, ie-0 and pe38 have been studied in detail and have been found to play vital roles in viral infection. In the type virus, Autographa californica MNPV, me53 is expressed at high levels from a immediate-early promoter. Although the gene has been defined transcriptionally, no attempt has been made to determine the function of me53. Me53 encodes a putative protein containing a C-4 zinc-finger and is thought to be involved in transcriptional transactivation. We have created a me53-null AcMNPV virus and have compared it to wild-type virus on the basis on infectivity, virus yield and DNA replication. Additionally we have tagged the me53 protein so it can be analyzed in protein studies.