• The Plant Pathology Journal
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• 제28권4호
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• pp.428-432
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• 2012

We determined the complete genome sequence of a Vietnamese isolate of Southern rice black-streaked dwarf virus (SRBSDV). Whole genome comparisons and phylogenetic analysis showed that the genome of the Vietnamese isolate shared high nucleotide sequence identities of over 97.5% with those of the reported Chinese isolates, confirming a common origin of them. Moreover, the greatest divergence between different SRBSDV isolates was found in the segments S1, S3, S4 and S6, which differs from the sequence alignment results between SRBSDV and Rice black streaked dwarf virus (RBSDV), implying that SRBSDV evolved in a unique way independent of RBSDV. This is the first report of a complete nucleotide sequence of SRBSDV from Vietnam and our data provides new clues for further understanding of molecular variation and epidemiology of SRBSDV in Southeast Asia.

• 대한바이러스학회지
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• 제28권4호
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• pp.369-375
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• 1998

In our preliminary study to find antiviral or antitumor agents from Korean natural products, we found that the Shope fibroma virus (SFV) induced fibromas reaching maximum size at $5{\sim}6$ days with spontaneous disappearance at $15{\sim}20$ days after SFV intracutaneous inoculation into Korean domestic rabbits. However, the sizes of fibromas of rabbits at day 5 after virus inoculation were significantly different individually. Assuming that the variation of tumor size was due to either susceptibility or the preexisting antibodies against SFV in the Korean domestic rabbits, the rabbits were checked for the antibodies against SFV by IFAT using SFV infected RK13 cells. The antibody positive rate of normal Korean domestic rabbits was 32.8% and the sizes of the fibromas of the positive rabbits were significantly smaller than those of negative rabbits (p<0.0001). The fibroma sizes were dependent on the antibody titers of rabbits to SFV. The sizes of fibromas after inoculation of SFV into immunized rabbits were about one tenth of those by the first inoculation into normal rabbits. This is the first report on the antibody prevalence against SFV among normal Korean domestic rabbits and it suggest the existence of a wild fibroma virus or related virus in Korea.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1800-1807
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• 2016

To understand how human cytomegalovirus (HCMV) might change and evolve after reactivation, it is very important to understand how the nucleotide sequence of cultured HCMV changes after in vitro passaging in cell culture, and how these changes affect the genome of HCMV and the consequent variation in amino acid sequence. Strain JHC of HCMV was propagated in vitro for more than 40 passages and its biological and genetic changes were monitored. For each passage, real-time PCR was performed in order to determine the genome copy number, and a plaque assay was employed to get virus infection titers. The infectious virus titers gradually increased with passaging in cell culture, whereas the number of virus genome copies remained relatively unchanged. A linear correlation was observed between the passage number and the log₁₀ infectious virus titer per virus genome copy number. To understand the genetic basis underlying the increase in HCMV infectivity with increasing passage, the whole-genome DNA sequence of the high-passage strain was determined and compared with the genome sequence of the low-passage strain. Out of 100 mutations found in the high-passage strain, only two were located in an open reading frame. A G-T substitution in the RL13 gene resulted in a nonsense mutation and caused an early stop. A G-A substitution in the UL122 gene generated an S-F nonsynonymous mutation. The mutations in the RL13 and UL122 genes might be related to the increase in virus infectivity, although the role of the mutations found in noncoding regions could not be excluded.

• Journal of Applied Biological Chemistry
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• 제63권3호
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• pp.189-195
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• 2020

The soybean (Glycine max L.), also known as the soya bean, is an economically important legume species. Pathogens are always major threats for soybean cultivation. Several pathogens negatively affect soybean production. The soybean is also known as a susceptible host to many viruses. Recently, we carried out systematic analyses to identify viruses infecting soybeans using soybean transcriptome data. Our screening results showed that only few soybean transcriptomes contained virus-associated sequences. In this study, we further carried out bioinformatics analyses using a soybean flower bud transcriptome for virus identification, genome assembly, and single nucleotide variations (SNVs). We assembled the genome of Soybean yellow common mosaic virus (SYCMV) isolate China and revealed two SNVs. Phylogenetic analyses using three viral proteins suggested that SYCMV isolate China is closely related to SYCMV isolates from South Korea. Furthermore, we found that replication and mutation of SYCMV is relatively low, which might be associated with flower bud tissue. The most interesting finding was that SYCMV was not detected in the cytoplasmic male sterility (CMS) line derived from the non-CMS line that was severely infected by SYCMV. In summary, in silico analyses identified SYCMV from the soybean flower bud transcriptome, and a nearly complete genome of SYCMV was successfully assembled. Our results suggest that the low level of virus replication and mutation for SYCMV might be associated with plant tissues. Moreover, we provide the first evidence that male sterility might be used to eliminate viruses in crop plants.

• 한국응용곤충학회지
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• 제15권2호
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• pp.61-68
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• 1976

광교, 동북태, 강림, 육우3호, 은대두등과 같은 대리장려품종이 바이러스에 의하여 심하게 이병되었다. 이 병은 주로 모자익병의 발생이 많은 강원, 경기지방에서 발병이 심하였으나 모자익병이 심하지 않은 전남 등 남부지방에서도 발병되고 있다. 병징으로 보아 tobacco ringspot virus에 의한 대두의 피해와 유사한 것으로 보였으나 지표식물검정과 혈청검정에 의하여 조사한 결과 모두 부정적이었으며 대두품종에 따른 이병정도의 상이, 품종과 접종원에 의한 병징의 변이가 많았다. 이병주에서 분리되는 병징형은 Mottling과 necrosis였으며 지금까지의 연구결과 이 대두병해는 모자익바이러스(SMV)의 계통 내지는 tobacco ringspot virus 이외의 두류바이러스의 복각감염에 의한 것으로 생각할 수 있으나 SMV의 계통에 의한 피해일 가능성이 더욱 유력시되고 있다.

• Journal of Veterinary Science
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• 제22권6호
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• pp.87.1-87.12
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• 2021

Background: African swine fever virus (ASFV), classical swine fever virus (CSFV), and porcine reproductive and respiratory syndrome virus (PRRSV) are still prevalent in many regions of China. Co-infections make it difficult to distinguish their clinical symptoms and pathological changes. Therefore, a rapid and specific method is needed for the differential detection of these pathogens. Objectives: The aim of this study was to develop a multiplex real-time quantitative reverse transcription polymerase chain reaction (multiplex qRT-PCR) for the simultaneous differential detection of ASFV, CSFV, and PRRSV. Methods: Three pairs of primers and TaqMan probes targeting the ASFV p72 gene, CSFV 5' untranslated region, and PRRSV ORF7 gene were designed. After optimizing the reaction conditions, including the annealing temperature, primer concentration, and probe concentration, multiplex qRT-PCR for simultaneous and differential detection of ASFV, CSFV, and PRRSV was developed. Subsequently, 1,143 clinical samples were detected to verify the practicality of the assay. Results: The multiplex qRT-PCR assay could specifically and simultaneously detect the ASFV, CSFV, and PRRSV with a detection limit of 1.78 × 10⁰ copies for the ASFV, CSFV, and PRRSV, but could not amplify the other major porcine viruses, such as pseudorabies virus, porcine circovirus type 1 (PCV1), PCV2, PCV3, foot-and-mouth disease virus, porcine parvovirus, atypical porcine pestivirus, and Senecavirus A. The assay had good repeatability with coefficients of variation of intra- and inter-assay of less than 1.2%. Finally, the assay was used to detect 1,143 clinical samples to evaluate its practicality in the field. The positive rates of ASFV, CSFV, and PRRSV were 25.63%, 9.36%, and 17.50%, respectively. The co-infection rates of ASFV+CSFV, ASFV+PRRSV, CSFV+PRRSV, and ASFV+CSFV+PRRSV were 2.45%, 2.36%, 1.57%, and 0.17%, respectively. Conclusions: The multiplex qRT-PCR developed in this study could provide a rapid, sensitive, specific diagnostic tool for the simultaneous and differential detection of ASFV, CSFV, and PRRSV.

• 대한바이러스학회지
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• 제28권1호
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• pp.11-20
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• 1998

Twenty isolates of Hantavirus were isolated from patients and reserovirs from 1988 to 1994 in Korea. Isolation rate was 1.9% (10/538) in patients, 6.2% (5/81) in Apodemus sp., 2.6% (1/38) in Rattus sp. and 0.6% (4/677) in bats. Reciprocal mean IFA titers ranged from 27.5 to 1,024 at the specimen collection. According to the growth rate and reaching peak titier of infectivity, the isolates were grouped as rapid, intermediate, and slow growing groups. All isolates were confirmed as Hantaan type by the nested RT-PCR on the G1 region of the M segment. Comparison of nucleotide sequence (Nt: 2101 - Nt: 2280) of the G2 region revealed that the sequence homology bewteen Hantaan 76/118 virus and the isolates was more than 90%. Several nucleotide positions of the isolates showed high variation. The variation rate of patientisolates was about one-half when compared with that of rodentisolates. On the basis of phylogenetic analysis Hantaan viruses isolated were divided into two genogroups. These results indicate that Hantaan virus is highly dominant serotype in Korea and the virologic property and genogroup are not correlated.

• The Plant Pathology Journal
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• 제18권3호
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• pp.130-137
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• 2002

Potato virus Y (PVY) is one of the most important viruses in many field crops in Korea. In this study, 31 PVY isolates were isolated from infected potato (Solanum tuberosum), tobacco (Nicotiana tabacum), pea (Pisum sativum), and weeds (Veronica persica, Lamium amplexicause and Capsella bursa-pastoris) showing different mosaic symptoms in Jeonbuk, Chungnam, Gangwon, and Gyeongbuk areas in Korea. The 640 nucleotide region containing the C-terminal portion of coat protein (CP) gene and 3'non-translated region (NTR) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using PVY-specific oligonucleotide primers. Sequence analyses of the amplified DNA fragments showed that the C-terminal portion of CP gene was not significantly different from that of previously reported PVY strains from potato (PVY-OK and -T) and tobacco (PVY-VN) in Korea. Homologies of the deduced CP amino acid sequences were 93.3-99.0% to corresponding regions of the other PVY strains including PV $Y^{N}$, PV $Y^{o}$ , PV $Y^{OK}$ , PV $Y^{T}$ , and PV $Y^{VN}$ . In contrast the sequences located at the 3'-NTR showed more diverse sequence homologies (76.4-99.7%). These results indicate that the C-terminal portion of the CP gene was relatively conserved while sequences at the 3'NTR were more diverse and variable over the host species and the regions where they were isolated.e isolated.

• The Plant Pathology Journal
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• 제27권2호
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• pp.148-155
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• 2011

Our previous sequence and phylogenetic analyses of the Korean Rice stripe virus (RSV) suggested possible genetic reassortment of RNA segments, but whether this RNA variation contributed to the recent RSV outbreaks in Korea is yet unclear. To further clarify these RSV-RNA segment variations, we developed a reverse transcription-polymerase reaction/restriction enzyme (RT-PCR/RE) analysis-based method. We identified five REs, including DraI, EcoR1, NdeI/AseI, and SpeI, that could differentiate RSV RNA 1-4 subtypes, respectively. Our RT-PCR/RE results provided a clear pattern of RNA reassortment, i.e., different groups of isolates having their RNA segments derived from two to three different RSV ancestors, such as from Eastern and Southwestern Chinese or Japanese M and T isolates. We also found that the migratory small brown planthopper from Eastern China caught by aerial net traps that possesses RSV-RNA3 genotypes corresponds mainly to Eastern China, with a few for Southwestern China based on RT-PCR/RE, sequence and phylogenetic analyses, indicating that RSV populations in Eastern China may also have strong RNA variation. The development of an RE analysisbased method proved a useful epidemiological tool for rapid genotyping and identification of mixed infections by RSV strain and by different subtype.

• 한국양봉학회지
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• 제32권4호
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• pp.281-293
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• 2017

Sacbrood virus (SBV) is one of the main pathogenic RNA viruses of honeybee. SBV is found worldwide and many local strains have been reported, such as kSBV, cSBV, and wSBV. In this study, SBV-specific DNA fragments were cloned and sequenced by reverse-transcription PCR from 4 populations of A. mellifera, 4 sequences from 1 population belonged to the 2134D51 genotype (349 nucleotides, nt) and 12 sequences from 3 populations belonged to the 2100D0 genotype (400 nt) among the 16 determined sequences. A total of 87 points of mismatches were found by comparison with the most similar sequences in GenBank. Seventeen single-nucleotide polymorphisms (SNP) were detected, and 6 SNP-patterns in the 2100D0 genotype and 2 SNP-patterns in the 2134D51 genotype were identified based on SNP positions. In SNP-pattern 2, 10 SNPs were detected, but only 2 SNPs were found in SNP-pattern7. Meanwhile, one SNP-pattern was found from one RNA-sample, multi SNP-patterns were detected from other RNA-samples. Large numbers of SNP variants indicate that vast numbers of point-mutations on SBV have occurred since SBV invaded Korea and that SNP smay have been introduced individually over time. Thorough analysis of SNP variants will not only define the local infection-route, but also the relationships between SNP-pattern and SBV-pathogenic abilities.