Chapter 11 - Polydnavirus Gene Expression Profiling: What We Know Now

Abstract

This chapter discusses the polydnavirus gene expression profiling. PDVs are divided into bracoviruses (BVs) and ichnoviruses (IVs), which are associated with wasps in selected subfamilies of the Braconidae and Ichneumonidae. The hosts for most PDV-carrying wasps are larval-stage Lepidoptera. Each PDV from a given wasp species is genetically distinct and exists in two states: a proviral form that is integrated into the wasp genome and is transmitted to offspring through the germ line; and an encapsidated form, which is produced only in the ovaries of females and which wasps inject into hosts when they oviposit. Importantly, the genes required for replication are not packaged into virions, which instead contain DNAs that encode a mixture of single-copy genes and multimember gene families whose products affect the physiology of hosts. One consequence of the differences in gene content between the proviral and encapsidated genomes of PDVs is that viruses injected into hosts cannot replicate.