Interactions of an Entomopoxvirus, its Parasitic Wasp Symbiont and their Insect Host: Viral Morphogenesis and Gene Expression

University Of Florida, Gainesville FL

Investigators

Abstract

The Caribbean fruit fly Anastrepha suspensa, like its Mediterranean fruit fly (Ceratitis capitata) relative, is an agricultural pest. The parasitic wasp, Diachasmimorpha longicaudata (Dl) is used worldwide as a biological control agent against these fruit flies. Dr. Lawrence discovered that female wasps inject an entomopoxvirus (EPV) into fruit fly larval hosts with their eggs, the combination of which causes host mortality. Since EPVs are utilized as microbial control agents against insect pests, DlEPV itself is a likely anti-fruit fly agent. However, it has not been characterized or is its relationship to other EPVs understood. The objectives of this research are to: (1A). sequence the gene of four putative proteins (DNA ligase and polymerase, RNA polymerase and refampicin resistant proteins which are important in virus replication and development) found in the DlEPV genome and compare them with those of known poxviruses (PVs) and EPVs; (1B). determine whether genes of known PVs and EPVs which encode proteins essential for viral infection and maturation have homologs in the DlEPV genome, (2A). determine whether certain DlEPV genes are expressed only within the wasp and others only in the fruit fly; and (2B). sequence selected genes that are differentially expressed in host versus wasp. The results will provide fundamental molecular data on the genome components of this unusual EPV, the first reported from a parasitic wasp, and establish its relationship to other EPVs. The presence of genes governing infectivity and those differentially expressed in host versus wasp would provide insights into the virus' ability to be non-pathogenic to wasps but infective and pathogenic to fruit files. The data will also lay the groundwork for the possible use of DlEPV as a vector to introduce lethal genes into fruit fly genomes