• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.991-993
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• 2012

We analyzed RNA polymerase beta subunit gene (rpoB) mutation of rifampin-resistant Mycobacteria through analysis of nucleotide sequence of rpoB DNA (351 bp) containing rifampin resistant region, $rif^r$. For this study, we collected rifampin-resistant Mycobacteria that were identified by conventional culture methods from Masan National Hospital and The Korean Institute of Tuberculosis. We performed sequencing of DNA nucleotides and analyzed rpoB gene of those rifampin-resistant Mycobacteria. From this analysis, we invcestigated diverse mutations of rpoB gene included rifampin-resistant gene, which were not reported, from those rifampin-resistant Mycobacteria.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.36-39
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• 2014

Many bacteria colonized in the horse semen affect quality of the sperm and some may cause infection in the mare reproductive tract and infertility of susceptible mare. This study was initiated to determine the prevalence of bacteria in testes of Jeju horses by determining rRNA sequence. The samples were swabed from the testes of nine Jeju horses (aged from 8 to 12 months after birth). Bacteria isolated from testes were identified by 16S rDNA sequencing. 1.6-kbp PCR products for 16S rRNA coding region were obtained using the universal primers. The PCR products were further purified and sequenced. Maximum similar species were found by BLAST search in the GenBank DNA database. BLAST results showed that the sequences were similar to those of Acinetobacter sp (A. schindleri, A. ursingii)., Bacillus cereus, Corynebacterium glutamicum, Escherichia coli, Gamma proteobacterium, Micrococcus luteus, Pseudomonas mendocina, Shigella sonnei, Sphingomonas sp., Staphylococcus sp (S. cohnii, S. saprophyticus, S. xylosus)., and Stenotrophomonas maltophilia. DNA sequences for 16S rRNA is provided useful informations for species identification of pathogenic microorganisms for the reproductive organs in horses.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.302-306
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• 2004

A total of forty strains of pigment-producing halophilic bacteria were isolated from the solar saltern and coastal seawater in Korea. The diversity of those bacteria were determined on the basis of PCR-RFLP and 16S rDNA sequences. The isolated strains were clssified into nine genera: Pseudoalteromonas, Photobacterium, Vibrio, Halobacillus, Bacillus, Paracoccus, Salinicoccus, Tenacilbaculum, and Flavobacterium. While more than $80\%$ of the pigment-producing halophilic bacteria isolated from the coastal seawater were classified as gram-negative Pseudolateromonas, most of the strains isolated from the solar saltern were classified into gram-positive Halo­bacillus. The other strain was KK7, which may be identified as novel species belonging to the genus, Salini­coccus.

• Clinical and Experimental Pediatrics
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• v.45 no.10
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• pp.1263-1272
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• 2002

Purpose : Rett syndrome(RTT) is an X-linked dominant neurodevelopmental disorder affecting 1 per 10,000-15,000 female births worldwide. It was initially described by Andreas Rett in 1966. RTT involves developmental regression characterized stereotypic hand movements, tremors, gait apraxia, seizures, deceleration of head growth after the age of 6-18 months. The disease-causing gene was identified as MECP2 on chromosome Xq28. We carried out mutational analysis of MECP2 genes in RTT patients. Methods : Whole blood(5 cc) of 34 sporadic RTT patients was collected in EDTA-anticoagulated tubes. Genomic DNA was extracted from peripheral blood using the E.Z.N.A. blood DNA kit. Four exons of the MECP2 gene were amplified by PCR in 34 Korean with RTT. We carried out PCR divided the exon three into two parts and the exon four into five parts. Primer sequences designed by Amir et al. in 1999 were almost used(AF030876). Sequencing primers used were the same as PCR. DNA sequencing reactions were performed using an ABI 377 DNA sequencer and ABI PRISM dye terminator cycle sequencing reaction kit(Perkin-elmer). The results were compared with the normal DNA sequence(X99686). To confirm the change of sequence on novel mutations, RFLP analysis was performed. Results : The MECP2 mutations were detected in 23(67.6%) of the 34 patients. The mutations consisted of 12 different types including nine missense and three nonsense mutations. Of these, three (L100V, G161E and T311M) mutations were newly identified. Most of the mutations discovered are located within MBD(39.1%) and TRD(39.1%). In this study, three(T158M, R270X, R306C) mutations were identified high frequency. Conclusion : MECP2 gene was also an important cause of Korean RTT patients. MECP2 gene study is an important tool for diagnosis of Korean RTT patients.

• KSBB Journal
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• v.19 no.1
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• pp.72-77
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• 2004

The aim of this study was to isolate and identify the spoilage bacteria in the low salt cucumber brine. The PCR amplicons comprising a portion of the 16S rRNA gene of the isolated colonies were directly sequenced and the untrimmed whole sequencing results of the unknown strains were aligned with the type strains using BLAST of NCBI. Then Sequence Aligner and Sequence Match of RDP confirmed the outcome. The identified isolates were eight species and belong to three genuses: Clostridium, Lactobacillus, and Bacillus. The RFLP pattern of the 16S rRNA gene of isolates verified the identified species. From now on the complex spoiling process of law salt fermented cucumber could be analyzed using the isolated species individually or with certain combinations.

• Journal of fish pathology
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• v.23 no.3
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• pp.313-322
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• 2010

Edible tunicate Halocynthia roretzi, one of the most commercially important aquatic organisms in Korea, has been killed by tunic softness syndrome since last decade. The intracellular protistan parasite observed by the transmission electron microscope in hemocytes of the tunicate was considered to be the causative agent of the mass mortality. The goal of the present work is to examine the characteristic features of the parasite by identifying the 18S rDNA sequences of the parasite. The experiments conducted include amplification of presumptive 18S rDNA from diseased tunicate tissues with UNonMet-PCR and sequencing the product. A preliminary phylogenetic analysis was performed on the presumptive parasite rDNA. A digoxigenin labeled DNA probe was designed on the basis of the sequences of rDNA. Dig-ISH assay was conducted to diagnose the protistan parasite. A PCR using UNonMet-PCR primer generated 595 bp SSU rDNA fragment. Subsequently, PCRs with primer pair expended this sequence to 1542 bp. This is the first partial sequences of SSU rDNA gene to be published on the protistan parasite that has presumed causing the mass mortality of tunicate. Since the Dig-ISH technique demonstrated the presence of infection in hemocytes on the all host tissues, the fragment was confirmed to be the intracellular protistan parasite SSU rDNA. A phylogenetic analysis suggested that the protistan parasite may be a unique eukaryote that is closely related to Apicomplexa.

• Journal of Life Science
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• v.27 no.5
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• pp.524-529
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• 2017

This study was aimed to produce a transgenic zebrafish expressing the human KCNE1 gene. Initially, the entire CDS of the human KCNE1 gene was amplified from a human genomic DNA sample by polymerase chain reaction using a primer set engineered with restriction enzyme sites (EcoRI, BamHI) at the 5' end of each primer. The resultant 402 bp KCNE1 amplicon flanked by EcoR1 and BamH1 was obtained and subsequently cloned into a plasmid vector pPB-CMVp-EF1-GreenPuro. The integrity of the cloned CDS sequence was confirmed by DNA sequencing analysis. Next, the recombinant vector containing the human KCNE1 (pPB-CMVp-hKCNE1-EF1-GreenPuro) was introduced into fertilized eggs of zebrafish by microinjection. Successful expression of the recombinant vector in the eggs was confirmed by the expression of the fluorescence protein encoded in the vector. Finally, in order to assure that the stable expression of the human KCNE1 gene occurred in the transgenic animal, RNAs were extracted from the animal and the presence of KCNE1 transcripts was confirmed by RT-PCT as well as DNA sequencing analysis. The study provides a methodology to construct a useful transgenic animal model applicable to the development of diagnostic technologies for gene therapy of LQTS (Long QT Syndrome) as well as tools for cloning of useful genes in fish.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.171-191
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• 2024

Identification of Helicotylenchus species is very challenging due to phenotypic plasticity and existence of cryptic species complexes. Recently, the use of rDNA barcodes has proven to be useful for identification of Helicotylenchus. Molecular markers are a quick diagnostic tool and are crucial for discriminating related species and resolving cryptic species complexes within this speciose genus. However, DNA barcoding is not an error-free approach. The public databases appear to be marred by incorrect sequences, arising from sequencing errors, mislabeling, and misidentifications. Herein, we provide a comprehensive analysis of the newly obtained, and published DNA sequences of Helicotylenchus, revealing the potential faults in the available DNA barcodes. A total of 97 sequences (25 nearly full-length 18S-rRNA, 12 partial 28S-rRNA, 16 partial internal transcribed spacer [ITS]-rRNA, and 44 partial cytochrome c oxidase subunit I [COI] gene sequences) were newly obtained in the present study. Phylogenetic relationships between species are given as inferred from the analyses of 103 sequences of 18S-rRNA, 469 sequences of 28S-rRNA, 183 sequences of ITS-rRNA, and 63 sequences of COI. Remarks on suggested corrections of published accessions in GenBank database are given. Additionally, COI gene sequences of H. dihystera, H. asiaticus and the contentious H. microlobus are provided herein for the first time. Similar to rDNA gene analyses, the COI sequences support the genetic distinctness and validity of H. microlobus. DNA barcodes from type material are needed for resolving the taxonomic status of the unresolved taxonomic groups within the genus.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.45-50
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• 2003

The diversity and change of microbial communities during kimchi fermentation at $4^{\circ}C$ were analyzed by denaturing gradient gel electrophoresis (DGGE). Kimchi samples were taken every 5 days over the fermentation periods (for 60 days) to extract total DNA for DGGE analysis. Touchdown polymerase chain reaction was performed to amplify the V3 region of 16S rRNA gene. Sequencing results of partial 16S rDNA amplicons from DGGE profiles revealed that lactic acid bacteria (LAB), especially Weissella koreensis, Lactobacillus sakei and Leuconostoc gelidum were dominants in kimchi fermentation at $4^{\circ}C$. And we knew that W. koreensis steadily existed throughout the whole fermentation period, also Lb. sakei and Leuc. gelidum appeared from 10th day and 30th day of fermentation time, respectively and then these species were to be dominant microorganisms.

• Journal of Microbiology
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• v.42 no.1
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• pp.9-13
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• 2004

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.