• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.87-92
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• 2008

Bombyx mori nucleopolyhedrovirus (BmNPV) orf47 gene was characterized for the first time. The coding sequence of Bm47 was amplified and subcloned into the prokaryotic expression vector pET-30a(+) in order to produce His-tagged fusion protein in the BL21 (DE3) cells. The His-Bm47 fusion protein was expressed efficiently after induction with IPTG. The purified fusion protein was used to immunize New Zealand white rabbits to prepare polyclonal antibody. As the genome of BmNPV is available in GenBank and the EST database of BmNPV is expanding, identification of novel genes of BmNPV was conceivable by data-mining techniques and bioinformatics tools. Structural bioinformatics approach to analyze the properties of Bm47 encodes protein.

• International Journal of Industrial Entomology and Biomaterials
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• v.21 no.1
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• pp.139-143
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• 2010

The objective of our study was the formulation of a local strain of Mamestra brassicae nucleopolyhedrovirus-K1 (MabrNPV-K1) for the development of viral insecticide to control M. brassicae. To formulate MabrNPV-K1, feeding toxicities of various supplements and ultraviolet (UV)-protection were investigated. Optical brightener Tinopal UNPA-GX (Tinopal) as UV protectant and Bentonite had some toxicity themselves to increase the mortality. The protection of polyhedra from UV light radiation was observed only by Tinopal. The MabrNPV-K1 was formulated as a wettable powder form. The mortality of the formulation was higher and rapid than that of the un-formulated. This suggested the possibility of MabrNPV-K1 formulation as an effective biological control agent for M. brassicae.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.1
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• pp.53-58
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• 2000

A cDNA encoding the luciferase of firefly Luciola lateralis was cloned downstream from the polyhedrin gene promoter of Bombyx mori nucleopolyhedrovirus and expressed in B. mori cells (BmN-4). The coding soquence for luciferase was inserted into pBmKSK2 rectors) which was reconstructed from the polyhedrin-based transfer vector pBmKSKl by modifying cloning sites. Recombinant virus, BmK2-LUCDF, containing the luciferase gene was selected and purified in BmN-4 cells. The emission of luminescence by luciferase was only detected in BmK2-LUCDF-infected cell extracts. This result indicates that the cloned new luciferase gene of firefly L. lateralis can be expressed efficiently in baculovirus expression system and used as a useful reporter gene.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.10a
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• pp.119-119
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• 2002

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.585-591
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• 2001

To compare the p10 promoter activity of Bombyx mori nucleopolyhedrovirus (BmNPV)K1 and K4, recombinant viruses Bm101-LacZ and Bm104-LacZ with a lacZ gene under the control of each p10 promoter were constructed. The $\beta$-galactosidase activity due to Bm101-LacZ was about 5.5- and 1.1-fold higher than that due to Bm104-LacZ and BmK1-LacZ, respectively. expressing ${\beta}$-galactosidase under the control of a polyhedrin promoter. The recombinant virus BmK1-104LacZ with the same genome structure as Bm101-LacZ, except for a p10 promoter region, produced a similar ${\beta}$-galactosidase activity to that due to Bm104-LacZ and 5.5-fold lower than that due to Bm101-LacZ. The virus yield, expression level of polyhedrin, and polyhedra productivity for each recombinant virus was almost similar. These results suggested that the difference in the expression level of ${\beta}$-galactosidase resulted from a difference in the p10 promoter regions, and that an expression vector using the p10 promoter of BmNPV-K1 could be usefully exploited in the mass production of foreign proteins with silkworm larvae by means of oral ingestion.

• BMB Reports
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• v.33 no.1
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• pp.63-68
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• 2000

Most baculoviruses have an ecdysteroid UDP-glucosyltransferase (egt) gene, whose product inactivates ecdysteroid within the infected host. Bomhyx mori larvae infected with BmEGTZ, a mutant B. mori nucleopolyhedrovirus (BmNPV) in which the egt gene has been inactivated, die more rapidly compared to larvae infected with wild-type BmNPV. In this study, the profile of hemolymph proteins, and progression of virus infection in BmEGTZ- and BmNPV-infected B. mori larvae, was analyzed by SDS-PAGE and histochemically. These analyses showed that virus-encoded and virus-induced proteins were expressed quicker in BmEGTZ-infected larvae than in BmNPV-infected larvae. This suggests that the decrease in time to death, following BmEGTZ infection, results from the stimulation of virus-specific protein expression. In order to examine the effect of ecdysteroid on virus transmission, the profile of hemolymph proteins, and progression of virus infection, were analyzed following an ecdysteroid injection of BmEGTZ- or BmNPV-infected larvae. In the BmNPV-infected larvae, ecdysteroid treatment had no apparent effect on hemolymph protein expression. This suggests that the injected ecdysteroid was inactivated by the BmNPV-expressed ecdysteroid UDP-glucosyltransferase. An Ecdysteroid injection into BmEGTZ-infected larvae increased the speed of virus-specific protein expression and virus transmission. These results suggest that ecdysteroid stimulates protein expression, which in tum results in the stimulation of virus transmission.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.145-149
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• 1999

To develop the baculovirus expression vector system (BEVS) adopting p10 gene promoter of Spodoptera exigua nucleopolyhedrovirus (SeNPV), we characterized the p10 gene of SeNPV. The nucleotide sequence of 545 bases including the coding region of p10 gene was determined. Compared with the previously reported SeNPV p10 gene (Zuidema et al., 1993), 4 bases were different in the 5' and 3' flanking region but no difference was found in the coding region. The p10 gene was located within Xho I 1.5 Kb, Sph 1 2.4 Kb and Cla I 4.0 Kb fragments by Southern hybridization analysis. Also, the Sph I 2.4 Kb and the Cla I 4.0 Kb fragments were cloned and their restriction enzyme maps were determined.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.159-163
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• 2003

This experiment was conducted to investigate pathogenicity of Spodoptera litura nucleopolyhedrovirus (SINPV) with different temperatures to mass production. In laboratory, LC$_{50}$ values of SINPV were 5.534$\times$10$^3$ PIBs/ml and 4.l0$\times$10$^2$PIBs/ml in 1st instar larvae at 2$0^{\circ}C$ and 28$^{\circ}C$, respectively, but those were increased at 32$^{\circ}C$. LC$_{50}$ at 3rd and 5th instar larvae were showed the lowest value at 28$^{\circ}C$. LT$_{50}$ values of SINPV in 1.0$\times$10$^{5.7}$ PIBs/ml were determined at various temperature conditions (20-32$^{\circ}C$). The result showed that treatments at 28$^{\circ}C$ and 32$^{\circ}C$ shortened LT$_{50}$ values, but treatments at 2$0^{\circ}C$ and 24$^{\circ}C$ was relatively longer. Also LT$_{50}$ values was shortened in high concentration and young larva. LT$_{50}$ values are dependent on the temperature, viral concentration and larval instar.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.153-157
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• 2003

This experiment was conducted to investigate control effect of Spodoptera litura using nucleopolyhedrovirus in chrysanthemum seedlings of open field and plastic house. Values of LT$_{50}$ of treatment 1.0$\times$10$^{6.8}$ PIBs/ml were 6.2-5.1 days in open field and 6.9-5.4 days in plastic house. Values of LT$_{50}$ and LT$_{95}$ were shorter in open field than in plastic house. Cumulative mortality was 100% in 1.0$\times$10$^{7.8}$ PIBs/ml and also higher in open field than in plastic house. In chrysanthemum field, organic synthetic insecticide (endosulfan EC) killed S. litura larvae in 2 days after application. Motality of S. litura larva inoculated with S. litura nucleopolyhedrovirus (SINPV) 1.0$\times$10$^{6.8}$ PIBs/ml was found out from 4 days after application and maintained during 14 days. Protection values of with SINPV 1.0$\times$10$^{8}$ PIBs/ml after 16 days were 94.0% and 89.4% in open field and plastic house, respectively, and those of endosulfan 350 ppm were 91.4% and 88.6%, respectively.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.449-460
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• 2022

The morphology and whole genome sequence of Spodoptera exigua nucleopolyhedrovirus K1 (SeNPV-K1) isolated in Korea were analyzed for the use as an eco-friendly control source against S. exigua. The polyhedra of SeNPV-K1 was amorphous with a size of 0.6-1.8 ㎛, and there was no external difference with the previously reported SeNPV. As a result of analyzing the nucleotide sequence of the whole genome, it was composed of 135,756 bp, which is 145 bp more than that of the previously reported SeNPV. The G+CG+C content was 44% and there were 6 homologous repeated sequences, so there was no significant difference from the previous report. As a result of ORF analysis, SeNPV-K1 had 137, two fewer than those previously reported, and 4 ORFs present only in SeNPV-K1 were confirmed. These 4 ORFs are non-essential genes and were not considered to have a significant influence on the characteristics of the SeNPV. The genome vista analysis showed that the overall sequence similarity between SeNPV-K1 and the previously reported SeNPV was very high. The whole genome of SeNPV-K1 analyzed for the first time in Korea was found to be similar to the previously reported SeNPV, but it was confirmed that it was a novel resource in Korea with different isolate.