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Submitted to: Virus Genes
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/21/2008 Publication Date: 2/1/2009 Citation: Harrison, R.L. 2009. Genomic sequence analysis of the Illinois strain of the Agrotis ipsilon multiple nucleopolyhedrovirus. Virus Genes. 38:155–170. Interpretive Summary: Insect pests cause billions of dollars of damage to crops each year. The use of chemical insecticides to control insect pests can have negative ecological, environmental, and health consequences. Baculoviruses are a group of insect viruses that can be used for biologically-based insect control without the problems of chemical insecticides. A more complete understanding of the genetic factors regulating baculovirus insecticidal activity is necessary for improving their scope and performance as biopesticides. In this study, the entire DNA sequence of a baculovirus isolated from the black cutworm was determined and analyzed. Features of the DNA sequence that may contribute to this virus’s insecticidal activity were documented. The information in this study provides clues for how to identify or develop baculovirus strains with enhanced insecticidal activity. Baculoviruses have a wide range of applications in addition to their use as biopesticides, and this study will be of interest to scientists in academia, government, and industry who work with this group of viruses. Technical Abstract: The Agrotis ipsilon multiple nucleopolyhedrovirus (AgipMNPV) is a group II nucleopolyhedrovirus (NPV) from the black cutworm, A. ipsilon, with potential as a biopesticide to control infestations of cutworm larvae. The genome of the Illinois strain of AgipMNPV was completely sequenced. The AgipMNPV genome was 155,122 not in size and contained 163 open reading frames (ORFs), including 61 ORFs found among all lepidopteran baculoviruses sequenced to date. Phylogenetic inference placed AgipMNPV in a clade with group II NPVs isolated from larvae of Agrotis and Spodoptera species. Though closely related to the Agrotis segetum NPV (AgseNPV), AgipMNPV was found to be missing fifteen ORFs present in the AgseNPV genome sequence, including two of the three enhancing genes identified in the AgseNPV genome. Remarkably few polymorphisms were identified in the AgipMNPV sequence even though an uncloned field isolate of this virus was sequenced. A genotype characterized by a 128-bp deletion in the ecdysteroid UDP-glucosyltransferase gene (egt) was identified in the AgipMNPV field isolate and among clonal isolates of AgipMNPV. The deletion in egt was not associated with differences in budded virus or occluded virus production among AgipMNPV clones in cell culture. |
