• The Journal of Korean Society of Virology
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• v.29 no.2
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• pp.75-86
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• 1999

Rotaviruses belong to Reoviridae causes diarrhea in human beings as well as domestic animals. This study was conducted to see what type of human rotaviruses are distributed in Seoul and Kyung-gi province. Twenty two of 81 patients showed rotavirus positive with diagnostic kit and RNA electropherosis. We isolated all of rotaviruses from the patients. Electropherotypes of 22 isolates showed 4:2:3:2 pattern whereas those migration patterns were long type. All of those isolates belonged to group A. Twenty out of 22 isolates reacted with monoclonal antibodies specific to G1, P1A and subgroup II, whereas rest of them, A-29 and K-30 reacted with subgroup I specific monoclonal antibody. The nucleotide sequence of an isolate K-21 showed $98{\sim}100%$ and $90{\sim}96%$ homologies with those of Wa and KU strain, respectively.

• Applied Microscopy
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• v.24 no.4
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• pp.107-114
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• 1994

The Rotaviruses are members of the family Reoviridae and are the major cause of severe childhood gastroenteritis worldwide. Recently, electron microscopy has been used to detect non-group A rotaviruses to determine a relatively high resolution structure of the rotavirion. Mature, infectious virions(double-shelled particles) have a diameter of approximately 70nm, and have a capsid structure composed of two concentric protein layers. We have studied patient's stool specimen by negative staining technique complete removal of sucrose suspension. This negative staining technique that could be carried out in about 30 minutes and that could be used with crude stool specimen was an advantage of major significance. Removal of sucrose in the sample by has been completed washing with distilled of sucrose and by washing with distilled water. Ultrastructurally, typical feature of rotavirus has a double capsid construction with an inner capsid of 55nm and on outer 65-70nm diameter can be clearly demonstrated.

• Journal of fish pathology
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• v.23 no.3
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• pp.335-342
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• 2010

In 2008, mass mortality was observed in paradise fish Macropodus opercularis which was imported from Indonesia. PCR of these fish found positive for megalocytivirus and Mycobacterium sp., while an unidentified virus was culture-isolated using CHSE-214 cells. In the present study, we investigated characterization of the unidentified virus and its pathogenicity to determine whether the virus was the causative agent of the mass mortality of paradise fish. The unidentified virus induced cytopathic effect (CPE) with syncytia in CHSE-214 and other fish cells, BF-2, GF, SSN-1, FSP and FFN. The virus was resistant against treatments with IUdR, chloroform, acidity at pH 3, basicity at pH 11 and high temperature at $56^{\circ}C$ for 3h. By electron microscopy, the viral particles were spherical having a double capsid structure with approximately 65 nm in external diameter. Viral genome was composed of at least 10-segmented RNA with sizes ranging from 0.7 kb to 3.6 kb. Based on these characters, this virus can be classified into family Reoviridae. This reovirus did not cause any mortality in an artificial experiment conducted by injecting the virus to paradise fish. This indicates that the reovirus is not only responsible for the mass mortality of paradise fish in 2008.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.632-637
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• 2007

A cytoplasmic polyhedrosis virus (CPV) was isolated from the larvae of Thaumetopoea pityocampa and shown to cause an infection of midgut cells. This viral infection revealed several important diagnostic symptoms, including discoloration of the posterior midgut, reduced feeding, and extended development time of the larvae. The virus infection is lethal to Thaumetopoea pityocampa, and with the increasing doses kills the larvae within 4-5 days post infection. Electron microscopy studies showed typical cytoplasmic polyhedral inclusion bodies that are icosahedral, and ranged from 2.4 to $5.3{\mu}m$ in diameter. Electrophoretic analysis of the RNA genome showed that the virus has a genome composed of 10 equimolar RNA segments with the sizes of 3,907, 3,716, 3,628, 3,249, 2,726, 1,914, 1,815, 1,256, 1,058, and 899 bp, respectively. Based on morphology and nucleic acid analysis, this virus was named Thaumetopoea pityocampa cytoplasmic polyhedrosis virus (TpCPV), and belongs to the genus Cypovirus, family Reoviridae.

• Research in Plant Disease
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• v.12 no.1
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• pp.25-27
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• 2006

Rice dwarf phytoreovirus (RDV), a member of the family Reoviridae has a genome composed of 12 segmented dsRNAs designated as 51 to 512 with an increasing order of mobility in polyacrylamide gel electrophoresis (PAGE). RDV encode 12 structural and non-structural proteins, $P1{\sim}P12$ which are encoded by the $S1{\sim}S12$ segments of the dsRNA genome, respectively. In this experiment, we confirmed in situ localization of RDV particles and P12 in cytoplasm of infected rice plant. We observed specific reaction of the gold particles using virus particle and P12 protein specific antiserum with protein A-gold immunolabelling in electron microscope. It was observed that gold particles specifically react to virus particles in cytoplasm in case using the antiserum for virus particles. In the case of antiserum for P12 protein, gold particles sporadically existing on cytoplasm without existing in organelle of cytoplasm specifically. As this result, RDV P12 protein encoded by S12 located in cytoplasm.

• The Journal of Korean Society of Virology
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• v.30 no.2
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• pp.101-112
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• 2000

Rotaviruses are the most common cause of severe vomiting and diarrhea in children worldwide and classified as a genus in the family Reoviridae. Rotavirus has eleven segmented dsRNAs and the virion consists of three shells. Outer capsid VP7 and VP4 induce neutralizing antibodies and are classified into G types (glycoprotein VP7) and P types (protease-sensitive VP4). Characterization of VP7 gene of Korean isolates of human rotavirus was performed using multiplex PCR and nucleotide sequence analysis. After RT-PCR amplification of full length (1,062 bp) of VP7 genes, the amplified PCR products were G typed by multiplex PCR and the nucleotide sequences were compared with those of reference rotavirus from GenBank. The G type analysis revealed that 25% (2/8) belong to G1, whereas 37.5% (3/8) benong to G2 and G4, respectively. The Korean isolates within the same serotypes showed high homology of nucleotide sequences and could be discriminated from foreign isolates exception with two strains (CAU009 and CAU022). But Korean isolates CAU009 and CAU022 were close related into japanease isolates 417 (99.2%) and indian isolates (97.6%) than Korean isolatese. Our results showed that these two strains were supposed to be originated from abroad. As a results, The G typing and nucleotide sequence analysis of VP7 gene of rotavirus isolated from infants in Korea could be used for identification, serotying and determination of novel or unusual strains of rotaviruses.

• 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.