Submitted to: Society for Invertebrate Pathology Annual Meeting
Publication Type: Book / chapter
Publication Acceptance Date: 4/5/2012
Publication Date: 7/20/2012
Citation: Harrison, R.L., Popham, H.J., Breitenbach, J.E., Rowley, D.L. 2012. Genetic diversity among isolates of Autographa californica multiple nucleopolyhedrovirus. In: 45th Annual Meeting of the Society for Invertebrate Pathology, August 5-9,2012, Beunos Aires, Argentina. pg.13. Interpretive Summary:
Technical Abstract: Our knowledge of genetic variation at the nucleotide sequence level of Autographa californica multiple nucleopolyhedrovirus (AcMNPV; Baculoviridae: Alphabaculovirus) derives from complete genome sequences of the C6 clonal isolate of AcMNPV and the R1 and CL3 clonal isolates of AcMNPV variants Rachiplusia ou MNPV (RoMNPV-R1) and Plutella xylostella MNPV (PlxyMNPV-CL3), along with individual gene sequences from other AcMNPV isolates. To obtain a more comprehensive view of genetic diversity among AcMNPV and AcMNPV-like viruses, sequence data of 74 virus samples from A. californica, Autographa gamma, Trichoplusia ni, Rachiplusia ou, Anagrapha falcifera, Galleria mellonella, and Heliothis virescens were generated by PCR. Nucleotide sequence analysis indicated that 45 samples contained isolates of AcMNPV, while six samples contained isolates of RoMNPV and 25 samples contained isolates of Trichoplusia ni single nucleopolyhedrovirus (TnSNPV). BLAST queries and phylogenetic inference from partial sequences of lef-8, lef-9, polh, ie-2, and the ORF ac86 region indicated a distinct group of AcMNPV isolates characterized by an unusual ie-2 gene previously found in PlxyMNPV-CL3 and a large deletion within ac86 originally described in the AcMNPV isolate 1.2. PCR and sequence analysis of bro genes suggested that the bro gene ac2 had been formed by a deletion that fused two adjacent bro genes together. In bioassays against T. ni larvae, significant differences were observed in the insecticidal properties of individual isolates, but no trends were observed among the AcMNPV, TnSNPV, or RoMNPV groups of isolates. This study expands on what we know about genetic diversity within AcMNPV and AcMNPV-like viruses.