Journal article
Removal of transposon target sites from the Autographa californica multiple nucleopolyhedrovirus fp25k gene delays, but does not prevent, accumulation of the few polyhedra phenotype
Journal of general virology, Vol.91(Pt 12), pp.3053-3064
12/2010
DOI: 10.1099/vir.0.024430-0
PMCID: PMC3052567
PMID: 20810745
Abstract
Low-cost, large-scale production of the baculovirus
Autographa californica
multiple nucleopolyhedrovirus (AcMNPV) using continuous insect cell culture is seriously hindered by the accumulation of AcMNPV mutants. Specifically, few-polyhedra (FP) mutants, with a reduced yield of occluded virus (polyhedra) and decreased infectivity, usually accumulate upon passaging in cell culture. FP mutations result from transposon insertions in the baculovirus
fp25k
gene, leading to significantly reduced levels of FP25K protein synthesis. This study evaluated the effects of removing the transposon insertion sites from the wild-type baculovirus
fp25k
gene; the mutated virus was denoted Ac-FPm. Specifically, this study involved a detailed comparison of wild-type (WT) AcMNPV and Ac-FPm with regard to the proportion of cells having polyhedra, number of polyhedra per cell, the fraction of empty polyhedra, number of occlusion-derived viruses per polyhedron, number of nucleocapsids in the nuclei, FP25K protein synthesis and genetic analysis of the
fp25k
gene. Removal of TTAA transposon insertion sites from the
fp25k
gene stabilized FP25K protein synthesis and delayed the appearance of the FP phenotype from passage 5 to passage 10. Electron micrographs revealed that more virus particles were found inside the nuclei of cells infected with Ac-FPm than in the nuclei of cells infected with WT AcMNPV (at passage 10). Abnormalities, however, were observed in envelopment of nucleocapsids and virus particle occlusion within Ac-FPm polyhedra. Thus, the FP phenotype appeared in spite of continued FP25K protein synthesis, suggesting that mechanisms other than
fp25k
gene disruption can lead to the FP phenotype.
Details
- Title: Subtitle
- Removal of transposon target sites from the Autographa californica multiple nucleopolyhedrovirus fp25k gene delays, but does not prevent, accumulation of the few polyhedra phenotype
- Creators
- Lopamudra Giri - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USAHuarang Li - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USADavid Sandgren - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USAMichael G Feiss - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USARichard Roller - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USABryony C Bonning - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USADavid W Murhammer - University of Iowa, Department of Microbiology, Iowa City, IA 52242, USA
- Resource Type
- Journal article
- Publication Details
- Journal of general virology, Vol.91(Pt 12), pp.3053-3064
- DOI
- 10.1099/vir.0.024430-0
- PMID
- 20810745
- PMCID
- PMC3052567
- NLM abbreviation
- J Gen Virol
- ISSN
- 0022-1317
- eISSN
- 1465-2099
- Publisher
- Society for General Microbiology
- Language
- English
- Date published
- 12/2010
- Academic Unit
- Microbiology and Immunology; Chemical and Biochemical Engineering
- Record Identifier
- 9984001130602771
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