• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.141.2-142
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• 2003

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing green mosaic and puckering symptoms at Anseong, Korea. Based on the biological tests, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the isolate was identified as Papaya ringspot virus type Watermelon (PRSV-W). In the biological test, host range of PRSV-W was limited in the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucurmis lanatus, Cucurmis sativus, Cucurbita pepo, and Citrullus lanatus, responded to mechanical inoculation by PRSV-W that induce green mosaic, malformation, puckering, and narrow laminae. The local lesion symptoms were produced on the inoculated leaves of Chenopodium maranticolor and C. quinoa PRSV specific primers which amplifies the part of the coat protein (CP) genes, generated a 648 bp product from 6 isolates of PRSV-W, but no amplification had been detected in other viruses including CMV, CGMMV, KGMMV, ZYMV and WMV. In electron microscopy, PRSV particles were flexuous, approximately 780 nm in length and 12 nm in width. PRSV-W is one of the worldwide viruses which has the great economic importance in cucumber, melon, squash, watermelon, and other cultivated cucurbits with ZYMV and WMV. This is the first report of PRSV-W on cucurbits in Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.525-531
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• 2008

CDH-13(T-cadherin), which is one of a kind among the 20 cadherins, can be found mainly in wall of aorta, neuron, spleen, blood vessel etc. It is also called H-cadherin. This structural difference can explain that CDH-13 is thought to play a key role in maintaining mutual relation between extra and intra-cellular environment rather than in cell adhesion. The main function of CDH-13 is to participate in blood vessel function. Additionally, it is known to regulate cell growth and cell contact inhibition. When cells are proliferating, cell surface perceives other cells so that substance such as CDH-13 can inhibit their growth or proliferation resulting in homeostasis without endless proliferation or invasion of connective tissue boundaries. However, tumor cell itself appears to be different from normal cells' growth, invasion or transmission. Therefore, it can be diagnosed that these characteristics are closely related to expression of CDH-13 in tumor cells. This study is to investigate expression of CDH-13 in SCC and its correlation with promoter methylation. 20 of tissue species for the study are excised and gathered from 20 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find development of CDH-13 in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1.Immunohistochemical staining: In normal oral squamous epithelial tissue, strong expression of CDH-13 was found in cell plasma membrane of basal cell layer. On the other hand, in case of low-differentiated oral SCC, development of CDH-13 was hardly seen. 2.The development of CDH-13 gene: In 9 of samples, expression of CDH-13 gene could be seen and 2 of them showed low expression compared to the others. And rest of the 11 samples showed no expression of CDH-13 gene. 3.Methylation of CDH-13 gene: Among 9 samples which expressed CDH-13 gene, 7 of them showed unmethylation. In addition, among 11 samples without CDH-13 gene expression, 10 showed methylation. According to the results stated above, promoter methylation were found in 13 samples(65%) among 20 of oral SCC samples. In low-differentiated SCC, suppression of gene expression could be seen accompanying promoter methylation. These phenomenon of gene expression was proved by immunohistochemical investigation. Finally, for development of oral SCC, conclusions can be made that suppression of CDH-13 played a main role and suppression of gene expression was originated from promoter methylation. Considering this, it is expected that suppression of CDH-13 from promoter methylation to be utilized as a good diagnostic marker of oral SCC.

• Parasites, Hosts and Diseases
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• v.56 no.2
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• pp.135-145
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• 2018

Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

• Korean Journal of Veterinary Service
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• v.43 no.1
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• pp.23-29
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• 2020

Hepatitis E Virus (HEV) infection is a worldwide disease and the primary cause of acute viral hepatitis in the world. It can be isolated from many different species including pigs. HEV is a zoonotic pathogen and foodborne disease. The main animal reservoir is domestic pigs. It is usually asymptomatic in pig but it is a public health concern, causing acute hepatitis in humans of varying severity. This study focused on the presence of HEV in pig and pork product. One hundred feces and one hundred fifty serum samples were randomly collected from pigs in slaughterhouses in Gwangju from November in 2018 to February in 2020. In addtion, seventy-five pork products were collected from markets in Gwangju. Feces and pork product samples were examined for the presence of HEV RNA using an reverse-transcription realtime PCR (RT-qPCR) assay. Serum samples were tested for the presence of HEV-specific IgG antibodies using Enzyme-linked immunosorbent assay (ELISA). HEV antigen and antibody positive rates were 3.0% (3/100) and 19.3% (29/150), respectively, in Gwangju and nearby areas such as Jeonnam and Jeonbuk. However, HEV antigen was not detected from any of pork product in this study. In conclusion, the prevalence of HEV should be continuously monitored because HEV was sporadically detected in Gwangju and nearby areas.

• Journal of Mushroom
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• v.15 no.3
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• pp.111-117
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• 2017

The mushroom species Cordyceps militaris has been studied and cultivated as a medicinal mushroom due to its multiple valuable biological and pharmaceutical activities. For breeding new strains of C. militaris, multiplex PCR assays were performed using primers specific for its mating type genes, MAT1-1 and MAT1-2. Mating types and mating status were confirmed, as evidenced by DNA bands at 233-bp and 191-bp for MAT1-1 and MAT1-2 respectively. The novel 'Dowonhongcho 2ho' was developed through mating; they were found to possess high-quality fruiting bodies when grown in artificial media. The stromata of the new strain were club-shaped, with a bright orange-red color, and measured 7.1 cm in length. They had an average cordycepin content of 0.33%. Compared to 'Dowonhongcho,' the new strain had a 7% higher yield, as well as firm fruiting bodies. The optimum temperature for mycelial growth was $20{\sim}25^{\circ}C$, and the optimum temperature for stroma development was $18{\sim}22^{\circ}C$. The fruiting bodies developed after 49.1 days from inoculation. The use of mating type molecular markers improved the breeding efficiency of the new strain 'Dowonhongcho 2ho.' Thus, they may be valuable for artificial cultivation and industrial-scale production of C. militaris with excellent characteristics.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.26-31
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• 2009

This study was aimed at the analysis of prokaryote communities in Korean traditional fermented food, jeotgal, and isolation of a novel strain from jeotgal by using culture-dependent and molecular biological approaches. Seventeen kinds of jeotgal were selected on the basis of its origins and sources. The samples were inoculated on 12 kinds of media. 308 isolates were selected randomly by morphological features, and its 16S rRNA gene sequences was amplified by PCR technique with bacteria and archaea specific primers (8F, 21F, and 1492R). The 16S rRNA gene sequences were compared with those in EzTaxon and GenBank databases. DNA-DNA hybridization was performed to identify a novel strain. As a result, the majority of the isolates were lactic acid bacteria (Leuconostoc, Weisella, Lactococcus, Lactobacillus, Carnobacterium, Marinilactibacillus), Bacillus, Pseudomonas, Micrococcus, Brevibacterium, Microbacterium and Kocuria in 17 kinds of jeotgal. The strains belonging to Salinicoccus, Halomonas, Cobetia, Lentibacillus, Paracoccus, and Psychrobacter were isolated as minor ones. Fourteen novel species were identified based on phylogenetic analysis.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.297-306
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• 2004

Heat shock proteins (HSPs) were induced in cells in the thermal stress, and the HSP90 family is one of the major classes of HSPs. Gene encoding HSPs have been characterized from various mammals and piscine. We have cloned and sequenced the HSP90 cDNA from a brain cDNA library constructed from flounder (Paralichthys oliThe result of sequence analysis shows it to be the HSP90~. The nucleotide sequence of the HSP90$\beta$ was composed of 2791 long, encoding 726 amino acid residues. The flounder hsp90$\beta$ gene showed very high sequence homology with hsp90f3 of European sea bass (96.6%), zebrafish (92.9%), Atlantic salmon (92.0%) and human (89.5%). We also constructed a phylogenetic tree based on HSP90 amino acid sequences from vertebrate species. Gene-specific primers were selected and used in RT-PCR reactions to measure the basal hsp90$\beta$ mRNA. The hsp90f3 gene is constitutively expressed at a fairly high level in all examined tissues (brain, liver, kidney, muscle, and spleen). In order to express protein of flounder hsp90$\beta$ in E. coli, we used the His-tagged pETvector. Then, the expression of flounder HSP90$\beta$ was confirmed by Western blot analysis.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.69-75
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• 2004

Vibrio vulnificus is a halophilic bacterium frequently involved in human infection of seafood-associated primary septicemia and primary wound infection, mostly in men with over 40-years of age with underlying liver disease. The primary septicemia, which is the most common form of V. vulnificus infection in Korea, is defined as a systemic illness presenting fever or hypotension with recovery of V. vulnificus from blood or tissue without the apparent primary focus of infection. V. vulnificus typically do not produce acid from sucrose, but a case of primary septisemia was found in a patient at Chonnam K hospital in 1993 from whose blood a sucrose-fermenting strain was isolated. The patient was a 62-year-old man, heavy drinker, with underlying liver disease. He consumed a raw seafood dish two days before onset of the present illness. His symptoms were tenderness and swelling on the right foot. He rapidly developed septicemia, resulting in sudden death. V. vulnificus was isolated from the venous blood culture of the patient. On subculture, the isolate formed yellow colonies on TCBS and produced acid from sucrose. Because of these characteristics, species identification was not achieved by the API 20E and was delayed. Other characteristics of the isolate were identical to those of typical V. vulnificus. The isolate was common serotype O4A and possession of V. vulnificus-specific cytolysin gene was detected by PCR. The isolate was susceptible to all the antimicrobial agents tested including tetracycline, but was intermediate to colistin. In conclusion, it is important that microbiologists be aware of the presence of sucrose-positive V. vulnificus when he or she identifies gram-negative bacilli, which is isolated from the blood of patients with a recent history of raw seafood dish consumption.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.281-286
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• 2014

In grape vineyards, whitish spots in a cloud shape have been often observed on the fruit surface recently. However, the cause of the halo spot symptom was unknown, hindering countermeasures to be properly designed for the control. A small hole in the middle of the formless halo spot remained as a scar formed by oviposition of the thrips. It became later a suberized scab, which is separated from the epidermal cells on the surface either to be retained on or to be detached from it as time proceeds. Such a symptom is distinguished from the feeding damages caused by thrips or true bugs occurring on the grape fruits. With DNA extracted from the egg-shell found in the hole, molecular diagnosis by amplifying an ITS2 region with universal primers and subsequently digesting the PCR product by an restriction enzyme (RsaI) revealed that the egg was laid by Frankliniella occidentalis. In addition, a mitochondrial COI sequence confirmed that the halo spot symptom was formed by its oviposition. This study provides accurate information on the peculiar damage symptom caused by oviposition of F. occidentalis that could be useful in the control strategies for this pest in vineyards.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.331-344
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• 2011

The well-conserved NBS domain of resistance (R) genes cloned from many plants allows the use of a PCR-based approach to isolate resistance gene analogs (RGAs). In this study, we isolated an RGA (CapRGC) from Capsicum annuum "CM334" using a PCR-based approach. This sequence encodes a protein with very high similarity to Rx genes, the Potato Virus X (PVX) R genes from potato. An evolutionary analysis of the CapRGC gene and its homologs retrieved by an extensive search of a Solanaceae database provided evidence that Rx-like genes (eight ESTs or genes that show very high similarity to Rx) appear to have diverged from R1 [an NBS-LRR R gene against late blight (Phytophthora infestans) from potato]-like genes. Structural comparison of the NBS domains of all the homologs in Solanaceae revealed that one novel motif, 14, is specific to the Rx-like genes, and also indicated that several other novel motifs are characteristic of the R1-like genes. Our results suggest that Rx-like genes are ancient but conserved. Furthermore, the novel conserved motifs can provide a basis for biochemical structural. function analysis and be used for degenerate primer design for the isolation of Rx-like sequences in other plant species. Comparative mapping study revealed that the position of CapRGC is syntenic to the locations of Rx and its homolog genes in the potato and tomato, but cosegregation analysis showed that CapRGC may not be the R gene against PVX in pepper. Our results confirm previous observations that the specificity of R genes is not conserved, while the structure and function of R genes are conserved. It appears that CapRGC may function as a resistance gene to another pathogen, such as the nematode to which the structure of CapRGC is most similar.