• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.365-375
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• 1996

5 serotypes(a, b, c, d, e) of Actinobacillus actinomycetemcomitans showed distinct hybridization patterns(DNA fingerprinting patterns) when the bacterial DNA were hybridized with randomly cloned 4.7-Kb sized DNA probe. The sizes of hybridized bands in each serotypes were different among serotypes and represented unique patterns of hybridization with the probe used. The serotype a showed two bands of fingerprinting patterns: 23.1 kb and 2.5 kb respectively. Serotype b and c showed single band: 6.6 kb and 9.5 kb, respectively. Serotype d and e showed two bands of hybridization: 23.1 kb and 2.8 kb, and 23.7 kb and 2.1 kb, respectively. The results indicate that this standard fingerpriting patterns of DNA hybridization with 4.7 kb probe can be further used for genotyping clinical isolates of Actinobacillus 8ctinomycetemcomitansand its relevance with periodontal disease activity.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.302-306
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• 2001

This study was carried out to construct mapping population and to evaluate the methods involved, including polymorphic DNA marker system and appropriate statistical analysis. As an initial step to establish chicken genome mapping project, White Leghorn (WL) and Korean Ogol chicken (KOC) were used for generating backcross population. From 8 initial parents, total 280 backcross progenies were obtained and 40 were used for genotyping and linkage analysis. For development of novel polymorphic markers for KOC, Random Amplified Polymorphic DNA (RAPD) markers specific for this chicken line were generated. Also included in this study were six microsatellite markers from East Lansing map as reference loci. For segregation analysis, 15 RAPD markers and 6 microsatellites were used to genotype the backcross population. Among the RAPD markers that we developed, 2 pairs of markers were identified to be linked and another 4 RAPD markers showed linkage with microsatellites of known map. In summary, this study showed that our backcross population generated from the mating of KOC to WL serves as a valuable genetic resource for genotyping. Furthermore, RAPD markers are proved to be valuable in linkage mapping analysis.

• BMB Reports
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• v.37 no.3
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• pp.269-274
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• 2004

DNA polymerases without the 3' exonuclease function ($exo^-$ pol) have been widely used in sequencing and SNP genotyping. As a major player that expedited the coming of the postgenomic era, $exo^-$ polymerases worked remarkably well in the Human Genome Sequencing Project. However, it has become a challenge for this class of polymerases to efficiently screen the large number of SNPs that are found in the human genome. For more than three decades it has been recognized that polymerase fidelity varied according to the presence of proofreading activity that is mediated by its internal 3' exonuclease. Polymerases with proofreading function are famous for their high fidelity in DNA replication both in vivo and in vitro, but this well-known class of polymerases has been almost completely neglected in genetic analysis in the postgenomic era. We speculate that $exo^+$ polymerases may exhibit higher nucleotide identification ability when compared to $exo^-$ polymerases for an in vitro genetic analysis. With the application of $exo^+$ polymerases in SNP assays, a novel mechanism for the maintenance of DNA replication, the on/off switch, was discovered. Two new SNP assays have been developed to carry out genome-wide genotyping, taking advantage of the enzymatic properties of $exo^+$ polymerases. Furthermore, the on/off switch mechanism embodies a powerful nucleotide identification ability, which can be used to discriminate the bases that are upstream of the 3' terminus, and thus defines a new concept in de novo sequencing technology. Application of $exo^+$ polymerases to genetic analysis, and especially SNP assays, will greatly accelerate the pace to personalized medicine.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1143-1147
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• 2014

Human papillomavirus (HPV) infection is considered to play a critical role in the development of cervical carcinoma, which is the third most common cancer among Korean females. Here, we performed a baseline study of HPV infection and genotyping using an HPV DNA chip, which is a type of oligonucleotide microarray. A total of 6,855 cervical swab specimens from 5,494 women attending Dankook University Hospital Health Improvement Center in Cheonan, Korea between 2006 and 2012, originally collected for HPV infection screening, were genotyped for HPV. The extracted DNA from the cervical specimens was investigated by an HPV DNA chip designed to detect 41 different HPV types. HPV was identified as positive in 1,143 (16.7%) of the 6,855 samples. The most frequently detected HPV genotypes were HPV types 16, 53, 56, 58, 39, 52, 70, 84, 68, 62, 35, 54, 81, 18, and 30, in descending order of incidence. The proportions of single and multiple HPV infections in the HPV-positive specimens were 78.1% and 21.9%, respectively. The average age of HPV-positive patients was 39.9 years, with the positive rate of HPV being the highest in the 10-29 age group (20.6%). We report here on the prevalence and distribution of 41 different genotypes of HPV according to age among women in Cheonan, Korea. These data may be of use as baseline data for the assessment of public health-related issues and for the development of area-specific HPV vaccines.

• The Plant Pathology Journal
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• v.37 no.5
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• pp.476-488
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• 2021

Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot for cruciferous vegetables worldwide, especially for the cole crops such as cabbage and cauliflower. Due to the lack of resistant cabbage cultivars, black rot has brought about considerable yield losses in recent years in China. Understanding of the pathogen features is a key step for disease prevention, however, the pathogen diversity, population structure, and virulence are largely unknown. In this study, we studied 50 Xcc strains including 39 Xcc isolates collected from cabbage in 20 regions across China, using multilocus sequence genotyping (MLST), repetitive DNA sequence-based PCR (rep-PCR), and pathogenicity tests. For MLST analysis, a total of 12 allelic profiles (AP) were generated, among which the largest AP was AP1 containing 32 strains. Further cluster analysis of rep-PCR divided all strains into 14 DNA groups, with the largest group DNA I comprising of 34 strains, most of which also belonged to AP1. Inoculation tests showed that the representative Xcc strains collected from diverse regions performed differential virulence against three brassica hosts compared with races 1 and 4. Interestingly, these results indicated that AP1/DNA I was not only the main pathotype in China, but also a novel group that differed from the previously reported type races in both genotype and virulence. To our knowledge, this is the first extensive genetic diversity survey for Xcc strains in China, which provides evidence for cabbage resistance breeding and opens the gate for further cabbage-Xcc interaction studies.

• ALGAE
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• v.24 no.4
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• pp.205-212
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• 2009

Molecular genetic tools are widely used to learn more about the identical characterization of obscure microalgal strains. At the Korea Marine Microalgae Culture Center (KMMCC), the authors deduced the genetic relationship of 41 strains of the genus Tetraselmis by analysing a small subunit ribosomal DNA (18S rDNA) sequences. Forty-one strains were seperated into five groups, which showed over a 98-99% similarity to Tetraselmis striata or Tetraselmis sp. Tsbre. Also, 13 strains among them had an identical genotype to Tetraselmis striata while 5 strains had with Tetraselmis sp. Tsbre, respectively. The mean size of each strain generally showed the tendency of different variation according to the groups.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.274-278
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• 1998

The biological father of two Golden Retriever puppies was determined between two proposed stud dogs by using microsatellite DNA analysis. DNA was obtained from all the relevant dogs by buccal swabbing and three loci of tetranucleotide repeat microsatellite were PCR-amplifiedl and analyzed by polyacrylamide gel electrophoresis and silver staining. One of the two proposed stud dogs was assigned as the biological father of the puppies by the genotyping. The result demonstrated that the microsatellite DNA analysis is a simple, efficient method of paternity test in dogs.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.343-353
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• 2006

Giardia intestinalis infections arise primarily from contaminated food or water Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was peformed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.

• Journal of Species Research
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• v.1 no.2
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• pp.240-248
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• 2012

We used a non-invasive technique with microsatellite primers to investigate genetic variation among Eurasian otters Lutra lutra in eastern South Korea. We collected twenty two otter spraints in January and six in August 2008. We used spraints from five dead otters from five different river systems for the present genetic analysis. We extracted DNA from 20 spraints from the January sample. Ten microsatellite primers (Lut435, Lut453, Lut457, Lut604, Lut615, Lut701, Lut715, Lut717, Lut733, and Lut832) for Eurasian otters were tested, and four loci were successfully amplified for further analyses. The results of genotyping the otter population with microsatellite loci lead to the identification of 9 individuals from the Ungokcheon Stream. The Ungokcheon population also showed a genetic structure represented by the Hardy-Weinberg equilibrium.

• Journal of Preventive Medicine and Public Health
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• v.40 no.2
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• pp.102-107
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• 2007

Human Genome Project (HGP) could unveil the secrets of human being by a long script of genetic codes, which enabled us to get access to mine the cause of diseases more efficiently. Two wheels for HGP, bioinformatics and high throughput technology are essential techniques for the genomic medicine. While microarray platforms are still evolving, we can screen more than 500,000 genotypes at once. Even we can sequence the whole genome of an organism within a day. Because the future medicne will focus on the genetic susceptibility of individuals, we need to find genetic variations of each person by efficient genotyping methods.