• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.287-293
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• 2010

Reliable discrimination of a single nucleotide mismatch was demonstrated using arrays with peptide nucleic acid (PNA) probes. The newly developed PNA probes immobilization method and hybridization conditions for PNA arrays gave excellent specificity and sensitivity. In addition we compared the specificity, sensitivity, and stability obtained with the PNA and DNA arrays in discriminating single nucleotide mismatches. The PNA arrays had superior perfect match-to-mismatch signal ratios and sensitivities. The relative signal intensities of mismatch PNA probes ranged from 1.6% to 12.1% of the perfect-match PNA probes. These results demonstrated that the PNA arrays were 2.0 to 37.3 times more specific and about 10 times more sensitive than DNA arrays. The PNA array showed the same specificity and sensitivity after 12-month storage at room temperature.

• BMB Reports
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• v.38 no.5
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• pp.555-562
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• 2005

Single nucleotide polymorphisms (SNPs) are becoming the most common type of markers used in genetic analysis. In the present report a SNP has been chosen to test the applicability of Real Time PCR to discriminate and quantify SNPs alleles on DNA pools. Amplification Refractory Mutation System (ARMS) and Mismatch Amplification Mutation Assay (MAMA) has been applied. Each assay has been pre-validated testing specificity and performances (linearity, PCR efficiency, interference limit, limit of detection, limit of quantification, precision and accuracy). Both the approaches achieve a precise and accurate estimation of the allele frequencies on pooled DNA samples in the range from 5% to 95% and don't require standard curves or calibrators. The lowest measurement that could be significantly distinguished from the background noise has been determined around the 1% for both the approaches, allowing to extend the range of quantifications from 1% to 99%. Furthermore applicability of Real Time PCR assays for general diagnostic purposes is discussed.

• BMB Reports
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• v.36 no.6
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• pp.529-532
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• 2003

The potential physiological role and technological application of the premature termination of DNA polymerization through the off-switch of exo+ polymerases were studied using 3' phosphorothioate-modified or unmodified primers with single base mismatch distal to the 3' terminus. With exonuclease-digestible unmodified primers, a gradient premature termination of DNA polymerization was observed when amplified with exo+ polymerases. With 3' allele specific phosphorothioate-modified primers, an efficient off-switch effect occurred in the discrimination of a single nucleotide polymorphism when directly using genomic DNA. Clearly, the off-switch of exo+ polymerases is useful in biomedical research.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.326-329
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• 2017

Background: Cultivated ginseng is often introduced as a substitute and adulterant of Russian wild ginseng due to its lower cost or misidentification caused by similarity in appearance with wild ginseng. The aim of this study is to develop a simple and reliable method to differentiate Russian wild ginseng from cultivated ginseng. Methods: The mitochondrial NADH dehydrogenase subunit 7 (nad7) intron 3 regions of Russian wild ginseng and Chinese cultivated ginseng were analyzed. Based on the multiple sequence alignment result, a specific primer for Russian wild ginseng was designed by introducing additional mismatch and allele-specific polymerase chain reaction (PCR) was performed for identification of wild ginseng. Real-time allele-specific PCR with endpoint analysis was used for validation of the developed Russian wild ginseng single nucleotide polymorphism (SNP) marker. Results: An SNP site specific to Russian wild ginseng was exploited by multiple alignments of mitochondrial nad7 intron 3 regions of different ginseng samples. With the SNP-based specific primer, Russian wild ginseng was successfully discriminated from Chinese and Korean cultivated ginseng samples by allele-specific PCR. The reliability and specificity of the SNP marker was validated by checking 20 individuals of Russian wild ginseng samples with real-time allele-specific PCR assay. Conclusion: An effective DNA method for molecular discrimination of Russian wild ginseng from Chinese and Korean cultivated ginseng was developed. The established real-time allele-specific PCR was simple and reliable, and the present method should be a crucial complement of chemical analysis for authentication of Russian wild ginseng.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.482-487
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• 2019

Background: The mixed-cultivation of different Panax ginseng cultivars can cause adverse effects on stability of yield and quality. K-1 is a superior cultivar with good root shape and stronger disease resistance. DNA markers mined from functional genes are clearly desirable for K-1, as they may associate with major traits and can be used for marker-assisted selection to maintain the high quality of Korean ginseng. Methods: Five genes encoding pathogenesis-related (PR) proteins of P. ginseng were amplified and compared for polymorphism mining. Primary, secondary, and tertiary structures of PR5 protein were analyzed by ExPASy-ProtParam, PSSpred, and I-TASSER methods, respectively. A coding single nucleotide polymorphism (SNP)-based specific primer was designed for K-1 by introducing a destabilizing mismatch within the 3' end. Allele-specific polymerase chain reaction (PCR) and real-time allele-specific PCR assays were conducted for molecular discrimination of K-1 from other cultivars and landraces. Results: A coding SNP leading to the modification of amino acid residue from aspartic acid to asparagine was exploited in PR5 gene of K-1 cultivar. Bioinformatics analysis showed that the modification of amino acid residue changed the secondary and tertiary structures of the PR5 protein. Primer KSR was designed for specific discrimination of K-1 from other ginseng cultivars and landraces. The developed real-time allele-specific PCR assay enabled easier automation and accurate genotyping of K-1 from a large number of ginseng samples. Conclusion: The SNP marker and the developed real-time allele-specific PCR assay will be useful not only for marker-assisted selection of K-1 cultivar but also for quality control in breeding and seed programs of P. ginseng.

• Molecules and Cells
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• v.21 no.1
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• pp.63-75
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• 2006

The 5′-region of Potato virus X (PVX) RNA, which contains an AC-rich, single-stranded region and stem-loop structure 1 (SL1), affects RNA replication and assembly. Using Systemic Evolution of Ligands by EXponential enrichment (SELEX) and the electrophoretic mobility shift assay, we demonstrate that SL1 interacts specifically with tobacco protoplast protein extracts (S100). The 36 nucleotides that correspond to the top region of SL1, which comprises stem C, loop C, stem D, and the tetra loop (TL), were randomized and bound to the S100. Remarkably, the wild-type (wt) sequence was selected in the second round, and the number of wt sequences increased as selection proceeded. All of the selected clones from the fifth round contained the wt sequence. Secondary structure predictions (mFOLD) of the recovered sequences revealed relatively stable stem-loop structures that resembled SL1, although the nucleotide sequences therein were different. Moreover, many of the clones selected in the fourth round conserved the TL and C-C mismatch, which suggests the importance of these elements in host protein binding. The SELEX clone that closely resembled the wt SL1 structure with the TL and C-C mismatch was able to replicate and cause systemic symptoms in plants, while most of the other winners replicated poorly only on inoculated leaves. The RNA replication level on protoplasts was also similarly affected. Taken together, these results indicate that the SL1 of PVX interacts with host protein(s) that play important roles related to virus replication.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.365-370
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• 2012

The two closely related major leguminous crop pests in Korea, Matsumuraeses phaseoli and M. falcana (Lepidoptera: Tortricidae) have very similar morphological characters, which occasionally give rise to a failure in distinguishing between the two. In this study, we report an easy PCR-SSP method to distinguish between them, with a sequence specific primer set (P-SF2, F-SF3, and C-SR3) based on single nucleotide mismatch in 3' terminal base of a primer, which is found in the mitochondrial cytochrome c oxidase subunit I DNA (mtCOI). Through application of this method, each species may be clearly identified in terms of its PCR band size and pattern, only one band (245 bp) for M. falcana and one (409 bp) or two bands (409 bp & 245 bp) for M. phaseoli.

• Journal of Life Science
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• v.28 no.9
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• pp.1062-1067
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• 2018

Reliable labeling of fish products can reassure consumers regarding the identity and quality of seafoods. Therefore, techniques that can identify adulteration or mislabeling are valuable. To rapidly identify two Trachurus species, Trachurus japonicus and Trachurus novaezelandiae, a highly efficient, rapid, duplex polymerase chain reaction (PCR) having two species-specific primers simultaneously was identified. This species-specific primer focused on a single nucleotide mismatch in the 3'-terminal base of a primer designed in the mitochondrial cytochrome c oxidase (COI) subunit I DNA. To optimize the duplex PCR condition, gradient PCR reactions were conducted to determine the primer annealing temperature and the primer concentration. The PCR's product was observed on the gel, suggesting that DNA molecules may be useful in differentiating the two species. The length of the amplification fragments were 103 bp for Trachurus japonicus and 214 bp for Trachurus novaezelandiae, which, along with the species-specific primer visualized by agarose gel electrophoresis, enabled accurate distinction of the species of the Trachurus genus. These results indicate that the duplex PCR, which has a species-specific primer based on single nucleotide polymorphism (SNP), can be useful for rapidly differentiating the two species of Trachurus. This duplex PCR analysis is simple, rapid, and reliable, and could be beneficial to protecting consumers' rights.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1393-1400
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• 2018

Objective: This study was carried out to assess the haplotype diversity and population dynamics in cattle populations of Ethiopia. Methods: We sequenced the complete mitochondrial cytochrome b gene of 76 animals from five indigenous and one Holstein Friesian${\times}$Barka cross bred cattle populations. Results: In the sequence analysis, 18 haplotypes were generated from 18 segregating sites and the average haplotype and nucleotide diversities were $0.7540{\pm}0.043$ and $0.0010{\pm}0.000$, respectively. The population differentiation analysis shows a weak population structure (4.55%) among the populations studied. Majority of the variation (95.45%) is observed by within populations. The overall average pair-wise distance ($F_{ST}$) was 0.049539 with the highest ($F_{ST}=0.1245$) and the lowest ($F_{ST}=0.011$) $F_{ST}$ distances observed between Boran and Abigar, and Sheko and Abigar from the indigenous cattle, respectively. The phylogenetic network analysis revealed that all the haplotypes detected clustered together with the Bos taurus cattle and converged to a haplogroup. No haplotype in Ethiopian cattle was observed clustered with the reference Bos indicus group. The mismatch distribution analysis indicates a single population expansion event among the cattle populations. Conclusion: Overall, high haplotype variability was observed among Ethiopian cattle populations and they share a common ancestor with Bos taurus.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.168-175
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• 2017

Single nucleotide polymorphisms (SNP) markers allow rapid screening of crop varieties in early growth stages. We developed a modified SNP PCR procedure for assaying SNPs in maize. For SNP marker development, we chosen 200 SNP sites from MaizeGDB database, and designed two base pair mismatch primers based on putative SNP site of B73 genome sequence. PCR products size was from 200 to 500 bp or was not shown in the case of SNP site existing in Korean silage corns. Using previously discovered 16 primer sets, we investigated distinctness of 50 silage F1 hybrid corns including 10 Korean silage corns developed by RDA such as Gangdaok, Kwangpyeongok, Dapyeongok, Andaok, Yanganok, Singwangok, Jangdaok, Cheongdaok, Pyeonggangok, and Pyeonganok as well as 40 foreign commercial silage corns. From cluster analysis, we confirmed that 10 Korean silage F1 hybrid corns were clearly distinguished except for Singwangok, P1395, and several foreign commercial corns, and selected minimum SNP primer combination for Gangdaok, Jangdaok, Pyeonggangok, and Pyeonganok. Therefore, development of SNP marker sets might be faster, cheaper, and feasible breed discrimination method through simple PCR and agarose gel electrophoresis.