• The Plant Pathology Journal
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• v.20 no.4
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• pp.264-270
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• 2004

Fusarium oxysporum f. sp. fragariae is a fungal pathogen causing strawberry wilt disease. The random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphisms (RFLPs) of intergenic spacer (IGS) region of rDNA were used to identify genetic variation among 22 F. oxysporum f. sp. fragariae isolates. All isolates could be distinguished from each other by RAPD analysis and RFLP of 2.6 kb amplified with primer CNS1 and CNL12 for IGS region of rDNA. Cluster analysis using UPGMA showed eight distinct clusters based on the banding patterns obtained from RAPD and rDNA RFLP. These results indicate that F. oxysporum f. sp. fragariae isolates are genetically distinct from each other, There was a high level genetic variation among F. oxysporum f. sp. fragariae.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.101-106
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• 1996

Tobacco mosaic virus (TMV) tomato strain was isolated from tomato "Seo-Kwang" in Korea. The virion was purified by density gradient centrifugation, and total viral RNA was isolated from the purified particles. Coat protein (CP) cDNA of the virus was synthesized by RT-PCR, and the purified cDNA fragment was subcloned to pBluescript II SK-. The analysis of nucleotide sequence showed that this cDNA was 693 nucleotides long from the insert of clone p1571 and p1572 which contain complete codons of the viral coat protein gene (474 nucleotides) and 3' untranslated region. The nucleotides of coat protein encoding cDNA of the strain were 6 nucleotides less than that of TMV common strain isolated from tobacco plant in Korea. The CP gene showed 70% maximum homology with that of the common strain in the nucleotide level and 86% maximum homology in amino acid level.cid level.

• Journal of Photoscience
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• v.7 no.2
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• pp.73-78
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• 2000

To analyze molecular traits determining pigmentation between Pharbitis nill violet and white, Amplified Fragment Length Polymorphism(AFLP) and Differential Display Reverse Transcription(DDRT) experiments were carried out with either genomic DNAs or total RNAs isolated from both plants. Results of AFLP experiment in combination of 8 EcoRⅠ primers with 6 MseⅠ primers showed 41 violet-and 60 white-specific DNA bands. In the subsequent experiment, 22 violet-and 22 white-specific DNA fragments were amplified by PCR with DNAs eluted. The sizes of the fragments range from 200 to 600bp. DDRT using total RNA produced 19 violet-and 17 white-specific cDNA fragments, ranging from 200 to 600bp. The fragments obtained by both AFLP and DDRT had been cloned into pGEM T-easy vector, amplified and subjected to the nucleotide sequence analyses. As a result of Blast sequence analysis, most of them sequenced up to date showed no similarity to any Known gene, while few has similarity to known animal or plant genes. An AFLP clone V6, for example, has a strong sequence similarity to the human transcription factor LZIP-alpha mRNA and a DDRT clone W19 to Solanum tuberosum 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.47-52
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• 1986

A heat-labile enterotoxin and no heat-stable enterotoxin producing($LT^+ST^-$) plasmid (110 kilobases in size) was isolated from an enterotoxigenic Escherichia coli of human strain O15:H11 and used for analysis of the $LT^+$ deoxyrionucleic acid region using recombinant DNA technology. A DNA segment containing the $LT^+$ DNA region which was one restriction endonuclease BamHl fragment(6.2 kb in size) was joind to a small multicopy plasmid, pUC9. E. coli K-12 strain, JM103 harboring the chimeric plasmid produced greater amounts of LT than did the enterotoxigenic E. coli O15:H11 strain. The BamHl fragment was further digested with various restriction endonucleases and contained no HindIll restriction site which is an essential in $LT^+ST^+$ plasmid. The detailed DNA sequencing of this $LT^+ST^-$ plasmid is required.

• Journal of Microbiology
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• v.38 no.2
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• pp.66-73
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• 2000

To investigate the genetic relationship among 12 species belonging to the Fusarium section Martiella, Dlaminia, Gibbosum, Arthrosporiella, Liseola and Elegans, the internal transcribed spacer(ITS) regions of ribosomal DNA (rDNA) were amplified with primer pITS1 and pITS4 using the polymerase chain reaction(PCR). After the amplified products were digested with 7 restriction enzymes, restriction fragment length polymorphism (RFLP) patterns were analyzed. The partial nucleotide sequences of the ITS region were determined and compared. Little variation was observed in the size of the amplified product having sizes of 550bp or 570bp. Based on the RFLP analysis, the 12 species studied were divided into 5 RFLP types. In particular, strains belonging to the section Martiella were separated into three RFLP types. Interestingly, the RFLP type of F. solani f. sp. piperis was identical with that of isolates belonging to the section Elegans. In the dendrogram derived from RFLP analysis of the ITS region, the Fusarium spp. examined were divided into two major groups. In general, section Martiella excluding F. solani f. sp. piperis showed relatively low similarity with the other section. The dendrogram based on the sequencing analysis of the ITS2 region also gave the same results as that of the RFLP analysis. As expected, 5.8S, a coding region, was highly conserved, whereas the ITS2 region was more variable and informative. The difference in the ITS2 region between the length of F. solani and its formae speciales excluding F. solani f. sp. piperis and that of other species was caused by the insertion/deletion of nucleotides in positions 143-148 and 179-192.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.561-571
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• 1999

Diagnosis of mycobacterial infection is dependent upon the isolation and identification of causative agents. The procedures involved are time consuming and technically demanding. To improve the laborious identification process mycobacterial systematics supported by gene analysis is feasible, being particularly useful for slowly growing or uncultivable mycobacteria. To complement genetic analysis for the differentiation and identification of mycobacterial species, an alternative marker gene, rpoB encoding the ${\beta}$ subunit of RNA polymerase, was investigated. rpoB DNAs (342 bp) were amplified from 52 reference strains of mycobacteria including Mycobacterium tuberculosis H37Rv (ATCC 27294) and clinical isolates by the PCR. The nucleotide sequences were directly determined (306 bp) and aligned using the multiple alignment algorithm in the MegAlign package (DNASTAR) and MEGA program. A phylogenetic tree was constructed with a neighborhood joining method. Comparative sequence analysis of rpoB DNA provided the basis for species differentiation. By being grouped into species-specific clusters with low sequence divergence among strains belonging to same species, all the clinical isolates could be easily identified. Furthermore RFLP analysis enabled rapid identification of clinical isolates.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.173-186
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• 2005

Genomic DNA was isolated from two geographic populations of largehead hairtail (Trichiurus lepturus) in Korea and the Atlantic Ocean. The eight arbitrarily selected primers were found to generate common, polymorphic, and specific fragments. The complexity of the banding patterns varied dramatically between primers from the two locations. The size of the DNA fragments also varied widely, from 150 bp (base pairs) to 3,000 bp. Here, 947 fragments were identified in the largehead hairtail population from Korea, and 642 in the largehead hairtail population from the Atlantic Ocean: 148 specific fragments (15.6%) in the Korean population, and 61 (9.5%) in the Atlantic population. In the Korean population, 638 common fragments with an average of 79.8 per primer were observed.; 429 common fragments, with an average of 53.6 per primer, were identified in the Atlantic population. The number of polymorphic fragments in the largehead hairtail population from Korea and the Atlantic Ocean was 76 and 27, respectively. Based on the average bandsharing values of all samples, the similarity matrix ranged from 0.784 to 0.922 in the Korean population, and from 0.833 to 0.990 in the Atlantic population. The bandsharing value of individuals within the Atlantic population was much higher than in the Korean population. The dendrogram obtained by the eight primers indicated two genetic clusters: cluster 1 (KOREAN 01~KOREAN 11), and cluster 2 (ATLANTIC 12~ATLANTIC 22). Individual KOREAN no. 10 from Korea was genetically most closely related to KOREAN no. 11 in the Korean population (genetic distance = 0.038). Ultimately, individual KOREAN no. 01 of the Korean population was most distantly related to ATLANTIC no. 16 of the Atlantic population (genetic distance = 0.708).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.8
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• pp.1071-1075
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• 2002

In order to identify and develop the specific DNA marker for the identification of Hanwoo (Korean Cattle) from other breeds, a specific DNA marker of 519 bp was identified and sequenced from polymorphic analysis using RAPD-PCR for 6 cattle breeds. Two different repetitive sequences, $(AAC)_5$ and $(GAAGA)_2$, were selected and designed to use specific probe to develop a DNA marker for Hanwoo specific. When the $(AAC)_5$ probe was applied, the 10 kb specific DNA marker showed in the DNA fingerprinting from 237 of 281 Hanwoo individuals. This novel Hanwoo specific DNA probe is useful to perform the marker-assisted selection for screening Hanwoo purity as an unique genetic source.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.88-94
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• 1997

The mitochondrial DNA (mtDNA) restriction fragment length polymorphi는 (RFLPs) of five populations were analyzed to delineate the stocks of Penaeus chinensis (Osbeck) in the Yellow Sea. Comparison of P. chinensis with P. japonicus to clarify the nucleotide divergence between two species was also carried out. Based on the fragment patterns, three composite haplotypes were analyzed in P. chinensis mtDNA as four naplotypes were in P. japonicus. Most individuals of each P. chinensis population are shared by one dominant haplotype. Another two haplotypes haying variations at the C/a I and hull sites were also distributed evenly in the Korean and Chinese populations. It is suggested that the gene exchange occurring between populations in the Yellow Sea is frequent. Average length of the mtDNA molecule was estimated to be about 16.44 kb in P. chinensis and 16.31 kb in P. japonicus, Sequence divergence (p) of mtDNA between two species estimated by using Upholt's (1977) fomula was $13.7\%$.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.292-303
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• 1998

The arbitrary primer polymerase chain reaction(AP-PCR) and Southern blot restriction fragment length polymorphism(RFLP) were used to genotype the cariogenic pathogen S. mutans in children. Following the morphologic chracteristics of colony on selective medium for S. mutans, total genomic DNA from 155 strains was extracted by conventional methods. Among 155 strains, 143 strains (92.3%) were confirmed S. mutans by PCR with dexA gene and 114 strains were used in this study. Three random sequence 10-base oligonucleotide primers were chosen for AP-PCR. The amplified DNA products were separated electrophoretically in a 2% agarose gel containing ethidium bromide and the banding patterns were compared among different strains. For RFLP analysis, DNA was digested with EcoRI and BamHI, separated on a 0.7 % agarose gel and transferred to a nylon membrane. The membrane was probed with a previously characterised 1.6 kilobases (kb) DNA fragment cloned from gtf B gene of S. mutans. The probe was labeled with isotope[$^{32}P-{\alpha}CTP$], and hybridized fragments were detected with intensifying screen. AP-PCR produced 4-8 DNA bands in the 0.25-10 kb regions and distinguished 9, 10 or 12 genotypes, depending on the specific primer used. Southern blot RFLP analysis revealed 2 hybridization patterns consisting of 1 DNA fragments 450, 500 bp. These results indicate that AP-PCR is more discriminative method for genotyping of S. mutans.