Functional analysis of virus-like particles produced by ancestral machinery in parasitoid wasps, Venturia canescens

The ichneumonid wasp, Venturia canescens, manages pest populations by depositing its eggs into host insects, caterpillars in the order Lepidoptera, resulting in the death of the host. V. canescens introduces a "parasitic arsenal" along with its eggs into the host, consisting of venom and domesticated virus-like particles (VLPs). VLPs originate from permanent integration of a pathogenic alphanudivirus genome into the wasp genome to produce VLPs that are beneficial and crucial for the parasitoid’s ability to parasitize its host. There is very little molecular information on how viral proteins work to produce VLPs and prevent the attack of eggs by host cells. Replication to produce VLPs relies upon a transcriptional cascade in wasp ovarian cells. “Early” gene products are often involved in the activation of “late” genes and in virion assembly, while “late” genes encode viral structural proteins. However, many viral genes of unknown function are present in V. canescens. The recent high-throughput proteomics data of V. canescens helped to identify which viral proteins are constitutes of mature VLPs. Viral proteins that are not present in VLPs are hypothesized to be involved in VLP assembly. This talk will address the functions of the viral proteins putatively involved in VLP assembly through RNA interference (RNAi)-mediated knockdowns. Results will determine the relative importance of individual viral genes in VLP assembly and production. These findings help explain how VLPs are maintained as a beneficial player in V. canescens system and are expected to expand our knowledge of virus manipulation and their protein delivery system(s).