• Korean Journal of Veterinary Research
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• v.45 no.1
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• pp.63-70
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• 2005

African swine fever (ASF) is an infectious disease of domestic and wild pigs for which there is no vaccine in the world. A proper surveillance of viral activity and a timely response to ASF outbreaks depend upon the rapid diagnosis of ASF viral infection. Internationally prescribed enzyme-linked immunosorbent assay (ELISA) is a fast, sensitive test routinely used in the diagnosis of the ASF. However, inactivated whole ASF virus antigen used in this test is a tedious to prepare and has a risk of outside exposure of infectious virus by laboratory accident during the preparation. An ASF virus noninfectious recombinant antigen is a safe and easily produced alternative antigen for use in diagnostic assay. We have cloned the ORF O61R gene of the ASF virus to generate a recombinant baculovirus producing the p12 protein in insect cells under control of the polyhedrin promoter as non-fusion protein. When used in an indirect ELISA, the p12 antigen showed reactivity with all known ASF positive pig sera but not with negative pig sera. Our results indicated that the p12 protein would be one of alternative antigens for diagnosis of the ASF.

• International Journal of Industrial Entomology and Biomaterials
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• v.30 no.2
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• pp.50-57
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• 2015

Porcine circovirus type 2 (PCV2) is an important infectious swine virus causing postweaning multisystemic wasting syndrome (PMWS). PCV2 capsid protein, encoded by ORF2 has type-specific epitopes, is very immunogenic, and is associated with the induction of neutralizing antibodies. For the efficient production of capsid protein, recombinant Autographa californica nucleopolyhedroviruses were generated to express ORF2 fused with two forms of a partial polyhedrin. Recombinant capsid protein was produced successfully with the partial polyhedrin fusion form and the yield was high, as was shown by SDS-PAGE. Production of recombinant capsid proteins in insect cells was confirmed by Western blot analysis using anti-His monoclonal antibody, anti-ORF2 monoclonal antibody, and anti-PCV2 porcine serum. Fusion expression with amino acids 19 to 110 of the polyhedrin increased the production of recombinant capsid protein, but fusion with amino acids 32 to 85 did not. Additionally, PCV2 capsid protein is a glycoprotein; however, the glycosylation of recombinant protein was not observed. The results of an Enzyme-linked immunosorbent assay (ELISA) showed that recombinant capsid proteins could be utilized as antigens for fast, large-scale diagnosis of PCV2-infected pigs. Our results suggest that the fusion expression of partial polyhedrin is able to increase the production of recombinant PCV2 capsid protein in insect cells.

• Journal of fish pathology
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• v.33 no.1
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• pp.77-81
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• 2020

This study was performed for screening yellow head virus(YHV) complex in 252 including 235 white leg shrimps (Litopenaeus vannamei) and 17 oriental shrimp (Fenneropenaeus chinensis) collected from 18 farms located in southwestern province of Korea. The virus complex was detected by nested reverse-transcriptase polymerase chain reaction (RT-PCR) assay. In the assay, amplicons were resulted in RNAs exracted from 38 shrimps (21 white leg shrimps and 17 oriental shrimps) obtained from 7 farms. In phylogenetic analysis using sequences of ORF1b gene, all 38 sequences obtained in this study formed an independent lineage with YHV-8 genotype firstly isolated in China, belonged to an YHV-8 clade.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.772-777
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• 1999

The uncaped genomic RNA of bovine viral diarrhea virus (BVDV) initiates translation by recruitment of eukaryotic translation initiation factors at the internal ribosome entry site (IRES). N-terminal protease ($N^{pro}$) is the first translation product of the open reading frame (ORF). By using the vaccinia virus SP6 RNA polymerase transient expression system, we showed previously that deletion of $N^{pro}$ region reduced translation by 21%. To better understand the biological significance of $N^{pro}$ for translation, we carried out a mutational analysis of the $N^{pro}$ region of BVDV cloned in the intercistronic region of a bicistronic reporter plasmid. We constructed a bicistronic expression vector in which the entire 5 UTR and the mutated $N^{pro}$ region (${\Delta}386-901$, ${\Delta}415-901$ and ${\Delta}657-901$) was cloned between two reporter genes, chloramphenicol acetyltransferase (CAT) and luciferase (LUC). In vivo translation analyses showed that $N^{pro}$ region was dispensible for efficient translation. The results indicate that the $N^{pro}$ region is not essential for BVDV RNA translation and the 3' boundary of BVDV IRES is expanded into $N^{pro}$ region, suggesting that $N^{pro}$ may not play a major role in BVDV replication.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.245-250
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• 2007

The complete genome sequence of Zucchini yellow mosaic virus stain A (ZYMV-A) isolated from a hollyhock (Althaea rosea) was determined by using RT-PCR with a series of primer sets. The virus genome consisted of 9593 nucleotides (nt), excluding the poly(A) tract at 3' terminus of the virus genome, with 5' and 3' untranslated region of 139 and 211 nt, respectively. The deduced polyprotein of ZYMV-A consisted of 3080 amino acid (aa) residues and was 351 kDa in molecular weight. All proteolytic cleavage sites of the polyprotein of ZYMV-A were compared with those of ZYMV strains, which showed the cleavage sites were conserved among ZYMV strains. The HC-Pro contained the KITC and PTK motifs, and the DAG motif was located at CP ORF of ZYMV-A, suggesting that ZYMV-A is aphid-transmissible. Phylogenetic tree analysis based on the complete genome among ZYMV strains or CP ORFs with other potyviruses showed ZYMV strains formed a distinct group. These results clearly confirmed that ZYMV-A was another distinct strain in ZYMV population at molecular level.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.221-229
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• 2002

Japanese encephalitis virus (JEV) persistence was established and maintained in Vero cell culture for over 1 year. Eleven clones of plaque morphology mutant JEV, with large and small plaque sizes, were obtained from the cell culture supernatant. Genomic RNA replication efficiency of the mutants in naive Vero cell appeared to correspond to their different plaque sizes. No significant changes in envelop protein ORF or in non-coding regions at both ends of the RNA genome suggested that there could be an unidentified factor(s) playing role in JEV attenuation. Unlike to the replication of wild-type JEV, the mutants did not induce severe degree of cytopathic effect in Vero cells upon infection. While obvious decrease of Bcl-2 and its mRNA expression and sharp increase of p53 in naive Vero cells infected with either wild-type JEV or the large plaque-forming mutant, those changes were not observed with the small plaque-forming one. Together with these observation, internucleosomal DNA fragmentation and chromosomal DNA profile in the Vero cells infected with the mutants suggest that an overall changes in cytopathic effect in the plaque morphology mutants-infected cells should be primarily due to the reduced genomic RNA replication and the compromised degree of p53-independent apoptosis by the virus infection at least in part.

• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.135-138
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• 2005

Two pairs of DNA primers were designed for the detection of the Zhenjiang (China) strain of Bombyx mori densonucleosis virus (BmDNV-Z). These primers were designed from the nucleotide sequence of major structural protein gene (putative VD1-ORF2). PCR amplification was attempted from different issues (including silk gland, blood, skin and midgut) and feces of the silkworm which infected wit BmDNV-Z were amplified by PCR. Both of the primers gave expected size of in the DNA bands from midgut and feces, but not in the DNA of silk gland, blood and skin. The two bands were sequenced, and their sequence were same as the sequence designed for. BmDNV-Z could be successfully detected in single silkworm after it was infected for 12 hrs, and could not be detected before 9 hrs after infected.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.129-133
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• 2003

The factors for symptom development caused by Beat curly top virus(BCTV) have been analyzed by using a molecular genetic approach based on expressing BCTV encoded proteins in transgenic plants. BCTV open reading frame (ORF) L4 expression in transgenic Arabidopsis resulted in abnormal plant development and the production of callus inflorescence stems and bumpy trichomes, confiming that this gene alone is a primary symptom determinant. The L4 gene expression by northern hybridization in transgenic plants and a range of phenotypes were analyzed.

• International Journal of Industrial Entomology and Biomaterials
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• v.2 no.2
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• pp.155-160
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• 2001

We have generated a novel baculovirus genome which can be maintained in Escherichia coli that facilitates the rapid and efficient generation of recombinant baculovirus expression vectors. To make $Occ^{+}$ recombinant expression vectors, polyhedrin gene under the control of p10 promoter was inserted to bAcGOZA and this genome was designated bApGOZA. As in bAcGOZA, bApGOZA lacks a portion of the essential ORF1629 gene, but includes a mini-F replicon and selectable kanamycin-resistance marker, This occasion-producing activity of bApGOZA can be used very conveniently for its oral infectivity to insect larvae in mass production of foreign protein and insecticides.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.85.1-85.6
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• 2020

A cold-adapted porcine reproductive and respiratory syndrome virus (CA-VR2332) was generated from the modified live virus strain VR2332. CA-VR2332 showed impaired growth when cultured at 37℃ with numerous mutations (^S731^F, ^E819^D, ^G975^E, and ^D1014^N) in the hypervariable region of the NSP2, in which the mutation ^S731^F might play a vital role in viral replication at 30℃. Conserved amino acid sequences of the GP5 protein suggests that CA-VR2332 is a promising candidate for producing an effective vaccine against PRRSV infection. Further studies on replication and immunogenicity in vivo are required to evaluate the properties of CA-VR2332.