• Applied Biological Chemistry
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• v.37 no.3
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• pp.148-153
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• 1994

Rice black-streaked dwarf virus (RBSDV), a member of the plant reoviridae fijivirus group, causes a serious damage for rice production in Korea. To characterize the RBSDV genome, virus particles were produced by feeding of planthopper (Laodelphax striatellus F.) carring RBSDV to maize plants for 2 days. In $30{\sim}40$ days after feeding, the viral particles were purified from the infected maize roots by using $10{\sim}40%$ sucrose gradient centrifugation. After treatment of 10% SDS to remove the viral coat proteins, ten viral double-stranded RNAs were resolved in agrose gel electrophoresis. Total dsRNA was then used to synthesize cDNA by reverse transcriptase and a cDNA library was constructed in the ${\lambda}gt11$ vector. The phages that contain RBSDV cDNA fragments were selected by hybridizing with the random-primed probe prepared from RBSDV dsRNAs. After subcloning of several cDNA fragments into the pUC19 plasmid vector, one clone (pRV3) was chosen for sequencing. The pRV3 clone was shown to be located on the RBSDV genome fragment No.3 by RNA gel-blot analysis. Sequence analysis of the clone revealed that the pRV3 contains two partial open reading frames.

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.57-67
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• 1975

The poxvirus group is considered to be a typical cytoplasmic inclusion forming virus. Every poxvirus has been reported to produce only one kind of inclusion in the infected tissues. A vague concept that inclusions of poxviruses are eosinophilic or acidophilic has prevailed. Although many papers and theories about the nature of the inclusion have been presented, most of them are not quite convincing on the point of the relations with virus multiplication, and an analysis of papers published showed that there seem to be many discrepancies in the descriptions of the nature of the poxvirus inclusions. Comparative studies on host-virus interaction with cowpox, orf, swinepox and fowlpox viruses which selected from each Group (I-IV) of poxviruses were performed from the morphological and virological standpoints. At first, in cowpox virus-FL cell system, as a comparative model, cytoplasmic inclusion, nucleic acid metabolism by autoradiography and detection of viral antigen by immunofluorescence were studied and obtained the results as follows: 1. The focus-like cytopathic effect (CPE) at early stage developed to entire culture at terminal stage of infection, and also the developing status of CPE was correlated to viral doses for inoculation. Two kinds of cytoplasmic inclusions which named A and B type were easily observed by Giemsa, hematoxylin-eosin (H & E) and May-Greenwald Giemsa (MGG) stainings in the infected cells. The B type inclusions were formed at early stage of infection and the A type inclusions were produced subsequently the B type formation. The B type which common type inclusion in poxviruses was a small compact or aggregate at early stage and developed to a large diffuse body at terminal stage of infection. On the other hand, the A type inclusion which depend upon the kind of virus was appeared as round and discrete shape, and its size and number was increased gradually during the culture period. It was characteristic to form distinct halos around the both types of inclusions in acid fixed, H & E stained preparations of infected cultures. The B type inclusion was always positive in Feulgen reaction and showed as DNA containing body but the A type inclusion was not. 2. In the relationship between inclusion and DNA metabolism of infected cells by the qualitative autoradiography using 3H-thymidine, the appearance of silver grains was coincided with B type inclusion but not with A type inclusion. This showed that the DNA synthesis was proceeded in all B type inclusions except those in the terminal stage with a diffuse form. This suggested that the B type inclusions are only sites of DNA synthesis and this was proceeded after the cell infection independently. The activity of DNA synthesis of the inclusions was nearly the same as that of the nucleic of normal cells and non-inclusion bearing cells. and non-inclusion bearing cells. Regardless of the size of the degree of DNA synthesis of the B type inclusion, inclusion bearing cells all showed remarkable suppression of nuclear DNA synthesis. 3. By the direct fluorescent antibody technique viral antigen in infected cells was detected. The B type inclusions have been proved to contain a great deal of viral antigen, whereas the basic substance of A type inclusion did not show antigenicity except the round edge. It was suggested that the round edge fluorescence might be caused by the glare of cytoplasmic viral antigen which pushed out and concentrated by the A type inclusion development. 4. Hemorrhagic red pock formations on chorioallantoic membrane of embryonated chicken egg had proved the characteristic of used viral strain. 5. By the above studies on the nature of two types of inclusions and the role they play in virus multiplication, it was concluded that the B type inclusion must be the site of the synthesis of viral DNA and protein as well as the site of the virus.

• Korean Journal of Head & Neck Oncology
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• v.23 no.1
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• pp.21-25
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• 2007

Background：Squamous cell carcinoma(SCC)of the palatine tonsils represents approximately 15-23% of all intraoral SCC. The most frequently reported risk factors for oropharyngeal cancer are smoking and alcohol. In a recent overview of HPV and tonsillar squamous cell carcinoma(TC), 51% contained HPV DNA, and HPV-16 being the most frequent type. We aimed to clarify whether HPV directly effects on the oncogenesis and biologic behavior of TC by comparison with infection prevalence, and physical status of virus. Material and Method：We used HPV genotyping DNA chip(Biocore, Korea, Seoul) arrayed by multiple oligonucleotide probes of L1 sequence of 26 types of HPV and HPV genotypes are identified by fluorescence scanner. The copy numbers of HPV E2 and E6 open reading frames(ORF) were assessed using a TaqMan-based 5'-exonuclease quantitative real-time PCR assay. The ratio of E2 to E6 copy numbers was calculated to determine the physical status of HPV-16 viral gene. Results：We observed a significant difference in HPV prevalence between 52 TCs and 69 CFTs(73.1% vs. 11.6%), and most of the HPVs were type 16(87.2%)and non-episomal(94.1%) state. Conclusions：This study regarding HPV infection prevalence and mechanism in the largest population of palatine tonsillar squamous cell carcinoma with chronic follicular tonsillitis revealed significant difference pf HPV prevalence between TC and CFT. Most of HPV were 16 type and integrated or mixed, HPV-16 integration could be directly related to tonsillar carcinogenesis.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.378-384
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• 2011

Tomato yellow leaf curl virus (TYLCV), a member of genus Begomovirus, was isolated in Korea in 2008. We sequenced and analyzed the DNA-A of 51 TYLCV isolates from Korea, and 13 of the TYLCV isolates were selected as type representatives of TYLCV from six Korean provinces. The 13 TYLCV isolates were classified into Korea Group 1 (KG1, nine isolates) and Korea Group 2 (KG2, four isolates) based on the results of phylogenetic analysis and genome size (2774 and 2781 nucleotides, respectively). A recombination detection program 3 (RDP3) revealed two recombinations between the TYLCV Korea isolates and other TYLCV isolates [Thailand (AF206674), Iran (AJ132711), and Israel (X76319)]. TYLCV Jeju isolate was characterized by two recombination events (E1 and E2) caused by the presence of E1 in ORF V1 and C3, which may seem to be the mutations of the high nucleotide transversion and transition rate. Collectively, our results suggest that the occurrence of nucleotide transversions and transitions in TYLCV DNA-A might have induced novel recombination events within the TYLCV Korea isolates.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.301-310
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• 2005

Foot-and-mouth disease (FMD) is a highly contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals, such as cattle, pigs, sheep, goats and buffalo. FMDV, a member of the Aphthovirus genus in the Picornaviridae family, is a non-enveloped icosahedral virus that contains a positive sense RNA of about 8.2 kb in size. The genome carries one open reading frame consisting of 3 regions: capsid protein coding region P1, replication related protein coding region P2, and RNA-dependent RNA polymerase coding region P3. FMDV infects pharynx epithelial cell in the respiratory tract and viral replication is active in lung epithelial cell. Morbidity is extremely high. A FMD outbreak in Korea in 2002 caused severe economic loss. Although intense research is undergoing to develop appropriate drugs to treat FMDV infection, there is no specific therapeutic for controlling FMDV infection. Moreover, there is an increasing demand for the development of vaccine strategies against FMDV infection in many countries. In this report, more effective prevention strategies against FMDV infection were reviewed.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.482-490
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• 2001

The gene for glycoprotein B (gB2) of HSV-2-strain G was subcloned, sequenced, recombinated into the lacZ-HcNPV, expressed in insect cells, and compared with the homologous gene of other HSV-2 strains. The ORF of the gB2 gene was 2,715 bp. The overall nucleotide sequence homology of te gB2 gene compared ith that of the two previously reported HSV-2 strains appeared to be over 98%. A recombinant virus named Baculo-gB2 protein in insect cells. The recombination was confirmed by a PCR and the expression was demonstrated by radio immunoprecipitation. Insect cells infected with the Baculo-gB2 virus synthesized and processed gB2 with approximately 120 kDa in the cells, and then secreted it into the culture media, where it reacted with a nomoclonal antibody to gB2. The gB2 polypeptide contained two main hydrophobic regions (a signal sequence from 1 to 23 amino acid residues, and a membrane anchor sequence from aa 745 to 798), eight N-glycosylation sites evenly distributed, and was rich in alanine (11.2%). Antibodies to this recombinant protein that were raised in mice recognized the viral gB2 and neutralized the infectivity of the HSV-2 in vitro. There results show that the gB2 protein was successfully porduced in insect cells and could be used to raise a protective neutralizing antibody. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• Korean Journal of Veterinary Research
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• v.44 no.2
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• pp.259-268
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• 2004

Porcine circovirus type 2 (PCV-2) has been associated with various disease in pigs worldwide including postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS). In this study, monoclonal antibodies (MAbs) against PCV were produced, characterized and applications of MAbs as diagnostic reagents were described. Spleen or lymph node cells from BALB/c mouse immunized respectively with PCV-1, PCV-2 or expressed PCV-2/ORF2 proteins in baculovirus were fused with SP2/0 myeloma cells using polyethylene glycol (PEG) and hybridoma cells producing PCV-1 or PCV-2-specific antibody were screened by an indirect immunofluorescence (IIF) test. A total of fifteen MAbs were produced against PCV. Six MAbs were PCV-1-specific and nine were PCV-2-specific. All PCV-1-specific MAbs reacted with only PCV-1 and all PCV-2-specific MAbs were reactive with only PCV-2 by IIF test. None of the MAbs was reactive with porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), porcine rotavirus (PRV), and transmissible gastroenteritis virus (TGEV). Some PCV-2-specific MAbs recognized the PCV-2 infected porcine tissues by IIF or immunohistochemistry (IHC) assay. From this experiment, it was confirmed that MAbs produced in this study were PCV-specific and could be used as reliable diagnostic reagents for PCV-1/PCV-2 detection and differentiation.

• Journal of fish pathology
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• v.35 no.2
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• pp.141-155
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• 2022

Rock bream iridovirus (RBIV) causes high mortality and economic losses in the rock bream (Oplegnathus fasciatus) aquaculture industry in Korea. Viral open reading frames (ORFs) expression profiling at different RBIV infection stages was investigated using microarray approaches. Rock bream were exposed to the virus and held for 7 days at 23 ℃ before the water temperature was reduced to 17 ℃. Herein, 28% mortality was observed from 24 to 35 days post infection (dpi), after which no mortality was observed until 70 dpi (end of the experiment). A total of 27 ORFs were significantly up- or down-regulated after RBIV infection. In RBIV-infected rock bream, four viral genes were expressed after 2 dpi. Most RBIV ORFs (26 genes, 96.2%) were significantly elevated between 7 and 20 dpi. Among them, 12 ORF (44.4%) transcripts reached their peak expression intensity at 15 dpi, and 14 ORFs (51.8%) were at peak expression intensity at 20 dpi. Expression levels began to decrease after 25 dpi, and 92.6% of ORFs (25 genes) were expressed below 1-fold at 70 dpi. From the microarray data, in addition to the viral infection, viral gene expression profiles were categorized into three infection stages, namely, early (2 dpi), middle (7 to 20 dpi), and recovery (25 and 70 dpi). RBIV ORFs 009R, 023R, 032L, 049L, and 056L were remarkably expressed during RBIV infection. Furthermore, six ORFs (001L, 013R, 052L, 053L, 058L, and 061L) were significantly expressed only at 20 dpi. To verify the cDNA microarray data, we performed quantitative real-time PCR, and the results were similar to that of the microarray. Our results provide novel observations on broader RBIV gene expression at different stages of infection and the development of control strategies against RBIV infection.

• Research in Plant Disease
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• v.22 no.4
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• pp.289-292
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• 2016

We surveyed the occurrence of Japanese yam mosaic virus (JYMV) on Yam in Gyeongsangbukdo pronvince from 2013 to 2015. The symptoms of JYMV were yellow stripes and chlorosis in yam leaves and the infection rate was ranged from 33.6% to 40.8%. We determined nucleotide sequence encoding the polyprotein of JYMV isolate BRI from yam leaves using next-generation sequencing (NGS) method. The partial nucleotide portion (7,736 nucleotides) of the genomic RNA of the JYMV isolate BRI has been sequenced (accession No. KU309315). The region sequenced includes a single open reading frame (ORF) encoding a polyprotein composed of 2,497 amino acids containing the coat protein (CP) and 3' untranslated region (UTR). The genomic organization of this isolate shows almost the same to that of other members of JYMV. The JYMV isolate BRI showed 77% to 79% nucleotide identity with the Japanese and Chinese strains and isolates. This is the first report of the genome nucleotide sequence of JYMV from Dioscorea opposita in Korea.

• BMB Reports
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• v.36 no.5
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• pp.514-519
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• 2003

The ribonucleotide reductase (RR) 2 gene of the HSV-2 strain G was cloned, sequenced, and expressed in an E. coli cell. The RR2 gene was located on the PstI 2.4 kb fragment, which was cloned and sequenced. The ORF of the gene was 1,011 bp and its termination codon was TAG; also, the CATATAA sequence was present in the promoter of the RR2 gene. A Poly A signal sequence (AATAAA) was found in the 3'-noncoding region. The RR2 proteins that were produced in the E. coli and Vero cells were confirmed using a Western blot analysis. SDS-PAGE revealed that the molecular weights of the fusion-RR2 that was produced in the E. coli cells were approximately 24 kDa and 38 kDa in the Vero cells. The RR2 proteins were soluble. The differences in the molecular weights might be due to modifications in the Vero cells.