• 미생물학회지
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• 제54권3호
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• pp.254-265
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• 2018

최근 양계업에 막대한 피해를 끼치는 조류독감은 한국에서 수천억원의 거대한 경제적 손실을 초래하였다. 병원균의 전염경로를 파악할 수 있다면 막대한 손해를 끼치는 생물학적 피해의 확산을 막고 일부 지역으로 제한하는데 큰 도움이 될 것이다. 병원균 DNA 서열의 계통학적인 분석을 통하여 감염된 숙주들을 방향성이 있는 연결선으로 연관짓는 전염 계통수를 얻을 수 있다. 지난 10여년간 유전적 데이터뿐만 아니라 역학 데이터를 이용한 전염 계통수 추론의 방법론적 발전이 이루어졌다. 이에, 본 연구에서는 전염 계통수 추론 방법을 이용하여 지난 2014년 한국에 발병한 고병원성 조류독감 H5N8에서 유래한 DNA 서열을 재분석하였다. 당시, H5N8 바이러스는 전라북도에서 시작하여 지역적으로 접해있는 4개의 지역으로 확산되어 나갔던 것으로 알려져 있다. 전염 계통수를 추론하는 베이지언 통계 방법인 Markov chain Monte Carlo를 반복적으로 시행하고 이를 종합하여 철새 외래종과 국내종 조류 숙주들의 전염 계통수를 추정하였다. 비록 연결선의 불확실성은 높았으나 추정된 전염 계통수를 통하여 당시 H5N8 바이러스는 전라북도에서 시작하고 충청남도를 거쳐 경기도로 퍼져나간 것을 확인할 수 있었다. 사육하는 오리와 같은 국내종 조류는 전염 계통수의 말단 노드에 위치하는 것으로 추정되었다. 이러한 결과를 통하여 야생 철새종이 2014년 한국의 H5N8 조류독감의 감염 매개자로 주된 역할을 하였다는 것을 재확인하였다.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.125-130
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• 1993

The araC prodrugs (1~5) carrying a special acyl group at 5'-Ο-or $N^4$-position were evaluated for in vitro antiviral activity against various human viruses. When tested against HSV-1 and HSV-2 cultured in the verso cells, the prodrugs exhibited slightly higher $ED_{50}$ values compared with one of the parent araC but showed more increased $CC_{50}$ values in all cases. Consequently the overall selectivity indexes of prodrugs were higher than that of arab. The prodrugs, except compound 5, exhibited very potent activity similar to that of araC ($ED_{50}$ about $0.12{\mu}g/mι$) when evaluated against another human DNA virus, cytomegarovirus. However, theses araC prodrugs were completely inactive against RNA viruses i.e. poliovirus and coxackie B3 virus at the concentration of 4250{\mu}g/mι.$

• Journal of Life Science
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• 제12권2호
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• pp.61-74
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• 2002

One of the major aims in studying plant viruses is to minimise the development of symptoms in infected plants. With the advent of in vitro transcript mediated research on plant viruses, substantial progress has been made. This article describes the biology of a plant specific RNA virus, Johnsongrass mosaic virus (JGMV), important to Australian sorghum and corn agriculture and, in particular, at a molecular level which of the RNA sequences in its genome that make it possible for the virus to move from cell to cell, and eventually spread systemically throughout the entire plant. The JGMV has caused considerable yield losses in maize and sorghum over a number of years in Australia. Incidents where 100% of the crop has been infected are on record. The use of this virus is convenient under laboratory conditions because it can be readily transmitted by mechanical inoculation with infected leaf sap, which obviates the need for maintaining aphid colonies. The JGMV is a single stranded positive sense RNA virus.

• 대한의생명과학회지
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• 제16권3호
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• pp.201-206
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• 2010

In order to develop procedures for the rapid isolation of recombinant sugar transporter in functional form from away from the endogenous insect cell transporter, gene fusion techniques were exploited. Briefly, BamH1-digested human HepG2 type glucose transport protein cDNA was first cloned into a transfer vector pBlueBacHis, containing a tract of six histidine residues. Recombinant baculoviruses including the human cDNA were then generated by allelic exchange following transfection of insect cells with wild-type BaculoGold virus DNA and the recombinant transfer vector. Plaque assay was then performed to obtain and purify recombinant viruses expressing the human transport protein. All the cell samples that had been infected with viruses from the several blue plaques exhibited a positive reaction in the immnuassay, demonstrating expression of the glucose transport protein. In contrast, no color development in the immunoassay was observed for cells infected with the wild-type virus or no virus. Immunoblot analysis showed that a major immunoreactive band of apparent Mr 43,000~44,000 was evident in the lysate from cells infected with the recombinant baculovirus. Following expression of the recombinant fusion protein with the metal-binding domain and enterokinase cleavage site, the fusion protein was recovered by competition with imidizole using immobilized metal charged resin. The leader peptide was then removed from the fusion protein by cleavage with porcine enterokinase. Final separation of the recombinant protein of the interest was achieved by passage over $Ni^{2+}$-charged resin under binding conditions. The expressed transport protein bound cytochalasin B and demonstrated a functional similarity to its human counterpart.

• 한국동물위생학회지
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• 제37권4호
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• pp.263-271
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• 2014

In this study, we developed a cost and time saving one-step multiplex RT-PCR for the simultaneous detection and differentiation of swine influenza viruses (SIV) and 2009 pandemic influenza H1N1 virus (pH1N1). The one-step multiplex RT-PCR using four sets of primer was confirmed to be capable of detection of all SIV subtypes and differential diagnosis of major SIV subtype H1, H3 and pH1N1 on individual or mixed viral culture samples. The sensitivity of the multiplex RT-PCR was determined to be at least $2^{-6}$ $HA/25{\mu}L$ of the presented SIVs, providing sufficient efficacy for a routine SIV monitoring in diagnostic laboratories. In addition, compared with the conventional RT-PCR methods that cannot avoid the carryover DNA contamination, the developed RT-PCR applied with the uracil DNA glycosylase (UNG) system was proven to prevent a false positive reaction by carryover contamination of the pre-amplified DNA. In conclusion, the one-step RT-PCR with UNG system could be applicable to detect and differentiate of SIV from the viral cultures without worry of carryover DNA contamination in clinical laboratories.

• The Plant Pathology Journal
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• 제20권2호
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• pp.147-154
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• 2004

A simple and reliable procedure for RT-PCR detection of Apple stem pitting virus (ASPV), Cherry rasp leaf virus (CRLV), and Cherry necrotic rusty mottle virus (CNRMV) was developed. Two virus specific primer sets for each virus were found to specifically detect each virus among fourteen sets of designed oligonucleotide primers. Total RNAs extracted from healthy and from ASPV-,CRLV- and CNRMV-infected plant tissues were used to synthesize cDNA using oligo dT primer and then amplified by virus-specific primers for each virus. Each primer specifically amplified DNA fragments of 578 bp and 306 bp products for ASPV (prAS CP-C and prAS CP-N primers, respectively); 697 bp and 429 bp products for CRLV (prCR4 and prCR5-JQ3D3 primers, respectively); and 370 bp and 257 bp products for CNRMV (prCN4 and prCN6-NEG 1 primers, respec-tively) by RT-PCR. DNA sequencing of amplified DNA fragments confirmed the nature of each amplified DNA. Altogether, these results suggest that these virus specific primer sets can specifically amplify viral sequences in infected tissues and thus indicate that they can be used for specific detection of each virus.

• The Plant Pathology Journal
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• 제39권5호
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• pp.449-465
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• 2023

Plants are challenged by various pathogens throughout their lives, such as bacteria, viruses, fungi, and insects; consequently, they have evolved several defense mechanisms. In addition, plants have developed localized and systematic immune responses due to biotic and abiotic stress exposure. Animals are known to activate DNA damage responses (DDRs) and DNA damage sensor immune signals in response to stress, and the process is well studied in animal systems. However, the links between stress perception and immune response through DDRs remain largely unknown in plants. To determine whether DDRs induce plant resistance to pathogens, Arabidopsis plants were treated with bleomycin, a DNA damage-inducing agent, and the replication levels of viral pathogens and growth of bacterial pathogens were determined. We observed that DDR-mediated resistance was specifically activated against viral pathogens, including turnip crinkle virus (TCV). DDR increased the expression level of pathogenesis-related (PR) genes and the total salicylic acid (SA) content and promoted mitogen-activated protein kinase signaling cascades, including the WRKY signaling pathway in Arabidopsis. Transcriptome analysis further revealed that defense-and SA-related genes were upregulated by DDR. The atm-2atr-2 double mutants were susceptible to TCV, indicating that the main DDR signaling pathway sensors play an important role in plant immune responses. In conclusion, DDRs activated basal immune responses to viral pathogens.

• 대한수의학회지
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• 제43권3호
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• pp.471-476
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• 2003

Malignant catarrhal fever (MCF) is a systemic disease of ruminants caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is a gamma herpesvirus, which induces frequent latent infection and often difficult to detect its antigens and even specific nucleic acids because of its low viral copies in the infected tissues. Histopathology, serology and polymerase chain reaction (PCR) were compared for the diagnosis of MCF using 10 bison infected with OvHV-2. Histopathological diagnosis was performed using the criteria which was based upon the pathognomic lesions. Serological diagnosis was conducted using its serum with competitive ELISA for the detection of antibodies of OvHV-2. Also, the nest PCR was performed with peripheral blood leukocytes for the detection of OvHV-2-specific DNAs. Primers 556 and 775 were used for the primary amplification, and primers 556 and 555 were used for the secondary amplification. As the results, positive cases were 6 by histopahology, 9 by serology and 10 by PCR. As comparing with other diagnostic methods, PCR was found to be more sensitive than histopathology and serology. The recent development of molecular diagnostic assays has provided powerful tools for investigating how viruses survive in nature. Development of PCR specific for viruses has dramatically improved the accuracy of diagnosis of viruses in clinically infected animals. Furthermore, amplification of viral genomic material by nest PCR represents the most sensitive method for the detection of viruses and might be detected successfully even though very low viral DNA copies. So, it could be used as the first choice for the detection of viral DNAs with low copies such as the status of latent infection. However, it has also some limitation of application like as false negative results by PCR inhibitors and false positive results by contamination. The results of this study suggest that the use of molecular biological methods like PCR may increase the accuracy for the diagnosis of infectious diseases. However, in diagnostic laboratory, it is recommended that PCR assay must be conducted with other diagnostic methods for more reliable diagnosis.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.42-47
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• 1996

AcNPV와 BmNPV를 배양세포주에서 동시감염시켜 선발한 숙주범위가 넓어진 재조합 바이러스인 RecB-727과 RecS-A6의 분자생물학적인 특성들을 조사하였다. 재조합 바이러스의 LT50 값을 조사한 결과, RecS-A6는 모바이러스인 BmNPV 보다 비교적 낮은 병원성을 보았으나 RecB-727은 거의 비슷한 수준의 높은 병원성을 나타내었다. 재조합 바이러스 DNA를 분리하여 모바이러스 DNA와 함께 제한효소 패턴을 비교한 결과 DNA 수준에서 재조합이 일어났음을 확인할 수 있었으며, 일부 유전자의 재조합을 예측할 수 있었다. 또한 p10 유전자에 대한 Southern blot 분석 결과 RecB-727의 p10 유전자는 AcNPV에서 유래되었으며, RecS-A6는 BmNPV의 p10 유전자를 갖고 있는 것으로 추정된다. 재조합 바이러스의 숙주범위 확장에 중요한 역할을 하는 것으로 알려진 DNA helicase 유전자 내의 HindIII-SacI 0.6kb 부위에 대하여 약 250 bp의 염기서열을 조사한 결과, 이 부위의 염기서열은 BmNPV helicase의 염기서열과 동일하였다.

• Journal of Oral Medicine and Pain
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• 제24권2호
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• pp.125-135
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• 1999

This study was performed to discover the underlining influences of Herpes Simplex virus (HSV) and Varicella Zoster virus (VZV), to detect the changes of whole protein and mucin level and to observe protein profiles in the saliva when recurrent aphthous ulcer (RAU) was present. Unstimulated whole saliva was collected from 23 patients who for over three years had a clinical history of RAU, in a group of 10 women and 13 men, ranging from 11 to 72 years of age, and 20 healthy subjects, in a group of 8 women and 12 men, who did not have the symptoms nor a past history of RAU. Through the means of Polymerization Chain Reaction, genomic DNA from the HSV and VZV was purified from the saliva samples for identifying precisely the two types of viruses, and the level of whole protein and sialic acids in the saliva and the ratio of sialic acid to whole protein were measured, and SDS-polyacrylamide gel electrophoresis was performed. The results obtained were as follows ; 1. 39.13% of patients showed 224 bp bands of VZV DNA, those were appeared more in patients than in control group (p<0.01), but there was no significant difference between patients and control group in HSV DNA (p>0.05). 2. The concentration of whole protein in men patients was lower than in men control group (p<0.05), but there were no significant differences between patients and control in other groups (p>0.05). 3. The concentration of sialic acids from patients was lower than control group in all groups (p<0.05). 4. The concentration of sialic acids in proportion to that of whole protein was lower in patients than in control group (p<0.05), and in the two women groups (p<0.01), but no noticeable difference was found between the two men groups (p>0.05). 5. There were no consistent differences observed in the protein profiles of patients with control group except that certain protein bands near 50 kDa was lower in patients than in control group. These results suggest that viruses such as HSV and VZV and reduction of salivary whole protein and mucin levels are related to development of RAU.