• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.111-114
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• 2000

The female pupae of the silkworms Bombyx mori, were injected with recombinant Autographa californica nuclear polyhedrosis virus (AcNPV) expressing green fluorescent protein (GFP) by percutaneous inoculation. When the 4 day-old female pupae were injected with 1x10$^{7}$ or 2${\times}$10$^{7}$ plaque forming units (pfu) of the recombinant AcNPV, oviposited number and egg weight were significantly decreased. Furthermore, the shape of the eggs was obviously divides into normal and abnormal shapes. The percentage of the eggs with an abnormal shape was 7.8% and 57.1% at 1${\times}$10$^{7}$ and 2${\times}$10$^{7}$ pfu inoculation, respectively. PCR analysis of the genomic DNA extracted from the eggs revealed that gfp and AcNPV ecdysteroid UDP-glucosyltransferase genes were amplified from both types of eggs with normal and abnormal shapes. The results demonstrate that AcNPV DNA, and gfp gene cloned into the AcNPV genome, injected in pupal stage were transmitted to eggs and remained stable through at least next generation.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.1
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• pp.19-26
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• 2001

Transformed Spodoptera frugiperda (Sf9) cells expressing baculovirus very late factor (VLF-1) were constructed by using Autograha nuclear polyhedrosis virus (AcNPV) immediate earthy gene (ie1). Neomycin-resistance gene as a selectable marker was introduced under the control of AcNPV ie1 promoter, and Bombyx mori nuclear polyhedrosis (BmNPV-K1) vlf-1 gene was introduced under the control of the Drosophila heat shock protein gene (hspr70) promoter to yield dual expression plasmid with two independent transcription units. It was transfected into Sf9 cells and cell clones expressing vlf-1 were selected by G4l8 treatment. Genomic DNA from transformed cells was isolated and integration of AcNPV iel harboring vlf-1 was confirmed by PCR using AcNPV iel-specific primers and Southern blot analysis. The transformed cells expressing VLF-1 in an infection-independent manner expressed foreign gene product of recombinant baculovirus in the earlier stage of infection compared with control Sf9 cells. These results suggest the possible to develop highly efficient transformed insect cells for baculovirus expression vector system.

• BMB Reports
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• v.38 no.1
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• Journal of Microbiology and Biotechnology
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• v.4 no.3
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• pp.183-190
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• 1994

Cell-free extracts prepared from cultured insect cells, Spodoptera. frugiperda, were analyzed for activation of early gene transcription of an insect baculovirus, Autographa californica nuclear polyhedrosis virus (AcNPV). The template DNA used for in vitro transcription assays contained promoter sites for the baculovirus genes that have been classified as immediate early ($\alpha$) or early genes. These genes are located in the HindIII-K/Q region of the AcNPV genome. Nuclei isolated from the AcNPV-infected Spodoptera frugiperda cells were also used for in vitro transcription analysis by RNase-mapping the labeled RNA synthesized from in vitro run-on reaction in the isolated nuclei. The genes studied by this technique were p26 and pl0 genes which were classified as delayed early and late gene, respectively. We found that transcription of the genes from the HindIII-K region was accurately initiated and unique in the whole cell extract obtained from uninfected cells, although abundance of the in vitro transcripts was reverse to that of in vivo RNA. With isolated nuclei transcription of the p26 gene was inhibited by $\alpha$-amanitin suggesting that the p26 gene was transcribed by host RNA polymerase II. However, transcription of the pl0 gene in isolated nuclei was not inhibited by $\alpha$-amanitin, but rather stimulated by the inhibitor. We also found that the synthesis of $\alpha$-amanitin-resistant RNA polymerase was begun before 6 hr p.i., the time point at which the onset of viral DNA replication as well as the appearance of a-amanitin-resistant viral transcripts were detected. These studies give us strong evidence to support the previous data that early genes of AcNPV were transcribed by host RNA polymerease III, while transcription of late genes was mediated at least by a novel $\alpha$-amanitin-resistant RNA polymerase.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.3
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• pp.121-135
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• 2011

We provide an economic evaluation model to help managers make reasonable decision for the investment in the appropriate type of cloud computing. Cloud computing can be classified into public, private and hybrid architecture and we evaluate their attractiveness using traditional NPV and real option methods. We conduct economic analysis by comparing traditional software delivery model with various types of cloud computing. The work compares each mode of cloud computing against each other using passive NPV and dynamic real-option method. For more objective and conservative evaluation of investment alternatives, we eliminate conventional benefits that are often subjective or hard to measure, and count only the reduction of investment cost and maintenance cost as benefit. We argue that hybrid and public cloud computing can be undervalued without their intrinsic options such as abandonment, expansion and contraction.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.111-116
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• 1998

To construct transformed Bm5 cells, Autographa californica nuclear polyhedrosis virus (AcNPV)IE1 gene, an immediate early viral gene was firstly used in this study. AcNPV IE1 gene, which shares on 95.3% uncleotide sequence homology with Bombyx mori nuclear polyhedrosis virus (BmNPV) IE1 gene, was isolated and cloned into pBluescript. Neomycin gene from pKO-neo was inserted under the control of the IE1 promoter to yield pAcIE1-neo. The plasmid pAcIE1-neo was transfected into Bm5 or Sf9 cells, and neomycin-resistant cells were selected in TC100 medium containing 10% fetal bovine serum (FBS) and 1 mg/$m\ell$ G418 for two weeks. Individual clones were picked and each was amplified for further characterization. The genomic DNA from neomycin-resistnt cells was isolated and characterized by PCR using AcNPV IE1 gene-specific primers and by Southern blot analysis using neomycin gene probe. We concluded that AcNPV IE1 gene was functional in B. moridrived Bm5 cells as well as Spodaptera frugiperda-derived Sf9 cells to produce stably-transformed insect cells.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.1
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• pp.10-18
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• 2014

Baculoviruses base vectors come to be regarded as methods for in vivo gene delivery and transient expression to the silkworm. In the case of silkworm, B. mori, two types of baculoviruses, AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV (Bombyx mori nuclear polyhedrosis virus), are potentially applicable as vectors. Recently, AcNPV showed promising results with some silkworm strains despite different host-specificities. We searched for a highly-permissive silkworm strain in the B. mori stocks of Kyungpook National University that could produce high levels of recombinant protein. Seventy strains were screened using the recombinant AcNPV/BmA3-Luc virus. Based on the measured luciferase activity, the strains could be divided into three groups, high-, middle-, and low-permissive strains, according to their relative recombinant protein expression levels. At 48 hours post-injection, the luciferase activity in the high-permissive strains was 500-fold greater than that of the low-permissive strains. At 72 hours post-injection, a significant elevation in luciferase activity was observed in the hemocytes of all strains. Then, based on the above results, the High Permissive Strain (HPS) S10 and the Low Permissive Strain (LPS) S39 were pick up and was carried out Dot blotting, RT-PCR and Real time PCR.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.305-315
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• 2021

The cotton leafworm, Spodoptera littoralis, is a major pest in Egypt and many countries worldwide, and causes heavy economic losses. As a result, management measures to control the spread of the worm are required. S. littoralis nucleopolyhedrovirus (SpliNPV) is one of the most promising bioagents for the efficient control of insect pests. In this study, a chitinase gene (chitA) of a 1.8 kb DNA fragment was cloned and fully characterized from SpliNPV-EG1, an Egyptian isolate. A sequence of 601 amino acids was deduced when the gene was completely sequenced with a predicted molecular mass of 67 kDa for the preprotein. Transcriptional analyses using reverse transcription polymerase chain reaction (RT-PCR) revealed that chitA transcripts were detected first at 12 h post infection (hpi) and remained detectable until 168 hpi, suggesting their transcriptional regulation from a putative late promoter motif. In addition, quantitative analysis using quantitative RT-PCR showed a steady increase of 7.86-fold at 12 hpi in chitA transcription levels, which increased up to 71.4-fold at 120 hpi. An approximately 50 kDa protein fragment with chitinolytic activity was purified from ChitA-induced bacterial culture and detected by western blotting with an anti-recombinant SpliNPV chitinase antibody. Moreover, purification of the expressed ChitA recombinant protein showed in vitro growth inhibition of two different fungi species, Fusarium solani and F. oxysporum, confirming that the enzyme assembly and activity was correct. The results supported the potential role and application of the SpliNPV-ChitA protein as a synergistic agent in agricultural fungal and pest control programs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1442-1448
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• 2010

The evaluation of the financial viability of a privatized infrastructure project is complex because of the uncertainties involved due to the project's scale, long concession period and complexity. Use the BOT option valuation(BOT-OV) model, for evaluating the financial analysis of a privatized infrastructure project. This sophisticated for financial evaluation compared with a traditional NPV analysis.

• The Journal of Fisheries Business Administration
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• v.43 no.3
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• pp.31-41
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• 2012

This paper was conducted to study the economic valuation for Nursery-Phase production of the tidal flat oyster in Korea. Benefit-cost(B/C) model used to indicate the effects of economic valuation. Using discounting rates(i.e., 4.5%, 6.5% and 8.5%), the model compared revenues and costs that occur at different times from 2012 to 2018. This study also estimated various submodels, which are Benefit Cost Ratio(B/C ratio), Net Present Value(NPV), Internal Ration of Return(IRR), to compare profit of Nursery-Phase production styles and analyzed returns to evaluate the scenarios. Sensitivity analysis were conducted for various scenarios. The results suggest as follows. First, the oyster spat to the shell height of 3~5cm was more profit than the shell height of 1~3cm. Second, all of sensitivity analysis with submodels were economic valuation such that B/C ratio > 1, NPV > 0 and IRR > discounting rate. Third, the payback period was about 3years after installed Nursery-Phase production system.