38th Annual Meeting of the Society for Invertebrate Pathology

August 7-11, 2005  Anchorage, Alaska, U.S.A
   

Analysis of the ability of exon0 homologues from heterologous baculoviruses to complement an AcMNPV exon0 (orf141) knockout mutant for the production of budded virus

Xiaojiang Dai1,2, Basil M. Arif3, Peter J. Krell2, and David A. Theilmann1
1Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C., Canada V0H 1Z0; 2Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1; 3Great Lakes Forestry Centre, Canadian Forest Service, Sault Ste Marie, Ontario, Canada P6A 2E5

Exon0 (orf141) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is required for efficient production of budded virus in the AcMNPV life cycle. This gene is highly conserved throughout the baculovirus Group I and Group II NPVs but it is not known if this important gene is virus or host specific. To test virus specificity we examined whether exon0 homologues from heterologous baculoviruses can complement an AcMNPV exon0 knockout mutant by rescuing budded virus production. AcMNPV exon0 was knocked out using recombination in an infectious bacmid. Exon0 homologues from five heterologous baculoviruses were co-transfected with the AcMNPV exon0 knockout. This included two Group I NPVs, Choristoneura fumiferana MNPV, Orgyia pseudotsugata MNPV, and three Group II NPVs, Trichoplusia ni Single NPV, Mamestra configurata (Maco) NPV-A, and MacoNPV-B. The exon0 homologous genes were HA-tagged and placed under control of the AcMNPV exon0 late promoter. Initial results showed that all the EXON0 homologues from the heterologous NPVs were able to rescue the AcMNPV exon0 knockout for budded virus production. However, exon0-knockout viruses with heterologous exon0s did not spread as efficiently as wild-type virus and it appeared that production of budded virus was also delayed. This suggests EXON0 contains virus specific determinants required for budded virus production.

This abstract may not be cited or reproduced.