• Food Science and Preservation
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• v.18 no.4
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• pp.604-611
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• 2011

Several wild yeasts were isolated from Korean grape varieties before and during spontaneous fermentation. Among them, four strains were isolated based on the alcohol content and flavor production in wine after fermentation of apple juice. In this study, the four yeast strains were identified and characterized. PCR-restriction fragment length polymorphism analysis of ITS I-5.8S-ITS II region with restriction endonuclease Hae III and Hinf I resulted in that all the strains showed a typical pattern of Saccharomyces cerevisiae. Pulse field gel electrophoresis showed three different chromosome patterns with a same band between strains SS89 and SS812. When ITS I-5.8S-ITS II sequences of the four strains were compared with one another, they were similar to those of Saccharomyces cerevisiae CBS 4054 type strain. Identity of the sequences was higher than 97% with those of the type strain. Phylogenetic analysis showed based on the sequences showed they were genetically closed to the type strain. The four identified strains were tested in a medium containing 200 ppm potassium metabisulfite, and the MM10 and WW108 inhibition rates resulted at up to 24 h. The four strains were tested at an incubation temperature of $30^{\circ}C$. The 30% sugar concentration in the medium (w/v) showed the highest growth in 36 h, especially in the case of SS89, which was close to growth 40. The four strains were tested in an 8% ethanol medium (v/v). Alcohol tolerance was initially kept in the incubation process. The strains began to adapt, however, to the exceeded resistance. The four strains showed the lowest inhibition rate at 24 h.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.729-735
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• 2008

Purpose : Chlamydia trachomatis is one of the most common sexually transmitted diseases and is also a cause of pneumonia in infants. Respiratory infections by respiratory viruses are also common for infants. The objectives of this study were to identify the clinical manifestations and to determine the prevalence of C. trachomatis respiratory infections and coinfections by respiratory viruses in infants younger than 6 months of age. Methods : For this study, we enrolled 6 months or younger infants who were admitted to the Dankook University Hospital between January 2002 and July 2007, with respiratory symptoms. Nasopharyngeal aspirates or throat swabs were collected within s d of hospitalization and C. trachomatis was detected using polymerase chain reaction (PCR). Patients who tested positive underwent multiplex PCR for respiratory viruses. Results : A total of 690 patients underwent chlamydial PCR testing and 36 (5.2%) had positive results. Of the 36, 28 (78%) were male; 30 were vaginally delivered. From the 36 patients positive for C. trachomatis, 26 underwent multiplex respiratory viral PCR; 12 were coinfected with viruses. Respiratory syncytial virus (RSV) was the most frequent pathogen that was detected in 6 patients. Increased C-reactive protein and fever were significant in patients coinfected with respiratory viruses. Conclusion : C. trachomatis can infected in infants delivered by cesarean section as well as in 6 months old or younger infants. Infant with C. trachomatis respiratory infections can also be coinfected with respiratory infection also coinfected with respiratory viruses. Further studies are needed to better understand the prevalence rates of the this infection and its coinfection rate with respiratory viruses.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.225-230
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• 2009

Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

• Journal of Life Science
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• v.30 no.1
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• pp.1-9
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• 2020

Pseudomonas syringae pv. actinidiae, the causal agent of a bacterial canker disease in kiwifruit, is subdivided into five genetically distinct populations, namely biovars 1, 2, 3, 5, and 6. Of these, strains belonging to biovar 3 are responsible for a pandemic bacterial canker of kiwifruits since 2008. This study aimed to characterize the structure of the biovar 3 population and investigate the origin of biovar 3 strains isolated in Korea. The genetic variability of fifteen biovar 3 strains, thirteen Korean and two Chinese, were evaluated through random amplified polymorphic DNA (RAPD)-PCR. The RAPD results revealed the presence of eight lineages, designated as subgroups I-VIII, across the biovar 3 strains used in this study. As the strains in subgroups II and III from China were not found in the Korean examples, we concluded that six genetically different biovar 3 subgroups (I, IV, V, VI, VII, and VIII) are present in Korea. In PCR analysis using primers specific to the strains of New Zealand and Europe, Korean strains in subgroups V and VI amplified the relevant DNA bands, suggesting that these were introduced from these two origins, respectively. PCR primers specific to subgroup VIII were developed to monitor the spread of the first biovar 3 strain in Korea, and investigations revealed that this strain was not found in Korea after its first occurrence.

• Biomedical Science Letters
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• v.26 no.3
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• pp.170-178
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• 2020

Mycobacterium tuberculosis (MTB) continues to be one of the main causative agents of tuberculosis (TB); moreover, the incidence of nontuberculous mycobacteria (NTM) infections has been rising gradually in both immunocompromised and immunocompetent patients. Precise and rapid detection and identification of MTB and NTM in respiratory specimens are thus important for MTB infection control. Molecular diagnostic methods based on the nucleic acid amplification test (NAAT) are known to be rapid, sensitive, and specific compared to the conventional acid-fast bacilli (AFB) smear and mycobacterial culture methods. In the present study, the clinical performances of three commercial molecular diagnostic assays, namely TB/NTM PCR (Biocore), MolecuTech Real MTB-ID^® (YD Diagnostics), and REBA Myco-ID^® (YD Diagnostics), were evaluated with a total of 92 respiratory specimens (22 AFB smear positives and 67 AFB smear negatives). The sensitivity and specificity of TB/NTM PCR were 100% and 75.81%, respectively. The corresponding values of MolecuTech Real MTB-ID^® and REBA Myco-ID^® were 56.52% and 90.32%, and 56.52% and 82.26%, respectively. TB/NTM PCR showed the highest sensitivity; however, the concordant rate was 10% compared with sequence analysis. Although MolecuTech Real MTB-ID^® showed lower sensitivity, its specificity was the highest among the three methods. REBA Myco-ID^® allowed accurate classification of NTM species; therefore, it was the most specific diagnostic method. Of the three PCR-based methods, MolecuTech Real MTB-ID^® showed the best performance. This method is expected to enable rapid and accurate identification of MTB and NTM.

• Journal of Genetic Medicine
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• v.6 no.2
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• pp.146-154
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• 2009

Multiplex ligation dependent probe amplification (MLPA) is a PCR-based method to detect gene dosage. Since its introduction, MLPA has been used to test a large number of genes for major deletions or duplications. Genetic testing, as a diagnostic tool for genetic disease, has been used primarily to identify point mutations, including base substitutions and small insertions/deletions, using PCR and sequence analysis. However, it is difficult to identify large deletions or duplications using routine PCR- gel based assays, especially in heterozygotes. The MLPA is a more feasible method for identification of gene dosage than another routine PCR-based methods, and better able to detect deleterious deletions or duplications. In addition to detection of gene dosage, MLPA can be applied to identify methylation patterns of target genes, aneuploidy during prenatal diagnoses, and large deletions or duplications that may be associated with various cancers. The MLPA method offers numerous advantages, as it requires only a small amount of template DNA, is applicable to a wide variety of applications, and is high-throughput. On the other hand, this method suffers from disadvantages including the possibility of false positive results affected by template DNA quality, difficulties identifying SNPs located in probe sequences, and analytical complications in quantitative aspects.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.7
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• pp.967-972
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• 2018

The genus Chattonella belonging to the class raphidophyceae, is a harmful algal bloom species. Recently, its occurrence has been increasing and expanding along the Korean coast. Species identification of the genus Chattonella only by morphological observation is difficult due to the lack of rigid cell walls. In this study, the morphological characteristics and genetic affinity of Chattonella sp. isolated from Deungnyang Bay in 2017 were examined. We carried out single-cell isolation from field samples then sequenced three different areas using the single-cell PCR method: 1) parts of ribosomal operon, the large subunit (LSU) of the rDNA, 2) the chloroplast-encoded subunit psaA of Photosystem I, and 3) rbcL encoding the large subunit of the Rubisco gene. The cells were morphologically very similar to the general genus Chattonella ($74.0{\pm}10.1{\mu}m$ in length, $33.1{\pm}3.6{\mu}m$ in width). The three partial gene sequences were insufficient to justify distinction at the species rank. However, they clustered at 99-100 % sequence similarity with C. marina, C. marina var. antiqua and C. marina var. ovata.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.415-422
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• 2021

Cotton is an important fiber crop, and its seeds are used as feed for dairy cattle. Crop biotechnology has been used to improve agronomic traits and quality in the agricultural industry. The frequent unintentional release of LM cotton into the environment in South Korea is attributed to the increased application of living modified (LM) cotton in food, feed, and processing industries. To identify and monitor the LM cotton, a method for detecting the approved LM cotton in South Korea is required. In this study, we developed a method for the simultaneous detection of four LM cotton varieties, MON757, MON88702, COT67B, and GHB811. The genetic information of each LM event was obtained from the European Commission-Joint Research Centre and Animal and Plant Quarantine Agency. We designed event-specific primers to develop a multiplex PCR method for LM cotton and confirmed the specific amplification. Using specificity assay, random reference material(RM) mixture analysis and limit of detection(LOD), we verified the accuracy and specificity of the multiplex PCR method. Our results demonstrate that the method enabled the detection of each event and validation of the specificity using other LM RMs. The efficiency of multiplex PCR was further verified using a random RM mixture. Based on the LOD, the method identified 25 ng of template DNA in a single reaction. In summary, we developed a multiplex PCR method for simultaneous detection of four LM cotton varieties, for possible application in LM volunteer analysis.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.161-162
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• 2000

Metalloprotease produced in Vibrio mimicus, in which zinc is an essential meta ion for catalytic activity, degrades a variety of biologically important substances including human collagen, several complement components, and immunoglobulin. For gene overexpression and convenient purification, VMC gene was constructed in pET22b(+) expression vector by using of PCR. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.184-193
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• 2007

In mammalian ovary, steroidogenic acute regulatory (StAR) protein mediates the true rate-limiting step of transport of cholesterol from outer to inner mitochondrial membrane. Appropriate expression of StAR gene represents an indispensable component of steroidogenesis and its regulation has been found to be species specific. However, limited information is available regarding StAR gene expression during estrous cycle in buffalo ovary. In the present study, expression, localization and hormonal regulation of StAR mRNA were analyzed by semi-quantitative RT-PCR in buffalo ovary and partial cDNA was cloned. Total RNA was isolated from whole follicles of different sizes, granulosa cells from different size follicles and postovulatory structures like corpus luteum and Corpus albicans. Semi-quantitative RT-PCR analyses showed StAR mRNA expression in the postovulatory structure, corpus luteum. No StAR mRNA was detected in total RNA isolated from whole follicles of different size including the preovulatory follicle (>9 mm in diameter). However, granulosa cells isolated from preovulatory follicles showed the moderate expression of StAR mRNA. To assess the hormonal regulation of StAR mRNA, primary culture of buffalo granulosa cells were treated with FSH (100 ng/ml) alone or along with IGF-I (100 ng/ml) for 12 to 18 h. The abundance of StAR mRNA increased in cells treated with FSH alone or FSH with IGF-I. However, effect of FSH with IGF-I on mRNA expression was found highly significant (p<0.01). In conclusion, differential expression of StAR messages was observed during estrous cycle in buffalo ovary. Also, there was a synergistic action of IGF-I on FSH stimulation of StAR gene.