Genotype co-occlusion as a novel paradigm for the development of virus-based insecticides: is the evidence sufficiently convincing yet?

Abstract

We have long recognized that insect pathogenic viruses have evolved to be effective pathogens, andnotnecessarilyeffective insecticides.Moleculartechniquesincreasinglydemonstrate the presence of genetic heterogeneity in populations of entomopathogenic viruses, particularly in baculoviruses.Here,we reportonhowwe haveexploitedthisdiversitytodevelopanovel technology based on four steps:(i) isolate dissection, (ii) genotype interaction analyses, (iii) construction of novel genotypemixturesto createuniquenon-natural combinations genotypes with 79insecticidalcharacteristics (iv) serial passage in vivoto refine the transmissibility of genotypemixtures.Theproduction of mixedgenotypeocclusion bodies (co-occlusion)and mixed genotypeocclusion derivedvirions(co-envelopment) is an integralpartof thistechnology.We show examplesof how co-envelopment/co-occlusion can be usedfor virusinsecticide development.Thisapproachhas been questionedas itappearstochallengea numberof the establishedmodels of baculovirusreplicationand host range.In response, we present the most recent evidence for the physicalassociationbetweenvirus nucleocapsidsin mixed genotypeocclusion bodies, and outline the unique possibilities that this technology represents for baculovirus researchand the development of novel biological ins