• BMB Reports
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• v.38 no.2
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• pp.191-197
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• 2005

Although the human genome has been nearly completely sequenced, the functions and the roles of the vast majority of the genes, and the influences of single nucleotide polymorphisms (SNPs) in these genes are not entirely known. A modified mutation detection method was developed for large-scale cloning of the possible SNPs between tumor and normal cells for facilitating the identification of genetic factors that associated with cancer formation and progression. The method involves hybridization of restriction enzyme-cut chromosomal DNA, cleavage and modification of the sites of differences by enzymes, and differential cloning of sequence variations with a designed vector. Experimental validations of the presence and location of sequence variations in the isolated clones by PCR and DNA sequencing support the capability of this method in identifying sequence differences between tumor cells and normal cells.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.12
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• pp.1637-1643
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• 2011

Korean native chickens are a very valuable chicken population in Korea and their prices are higher than that of commercial broilers. In order to discriminate two commercial Korean native chicken populations (CCP1 and CCP2), single nucleotide polymorphisms (SNPs) from mitochondrial (mt) DNA D-loop sequences and LEI0258 marker polymorphisms in the major histocompatibility complex (MHC) region were investigated. A total of 718 birds from nine populations were sampled and 432 mtDNA sequences were obtained. Of these, two commercial Korean native chicken populations (363 birds) were used for investigation of their genetic relationship and breed differentiation. The sequence data classified the chickens into 20 clades, with the largest number of birds represented in clade 1. Analysis of the clade distribution indicated the genetic diversity and relation among the populations. Based on the mtDNA sequence analysis, three selected SNPs from mtDNA polymorphisms were used for the breed identification. The combination of identification probability (Pi) between CCP1 and CCP2 using SNPs from mtDNA and LEI0258 marker polymorphisms was 86.9% and 86.1%, respectively, indicating the utility of these markers for breed identification. The results will be applicable in designing breeding and conservation strategies for the Korean native chicken populations and also used for the development of breed identification markers.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.305-310
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• 1996

Five edible mountain vegetables(Saussurea sp. Aster tataricus, A. scaber. Synurus deltoides, Ligularia fischeri) were investigated on the basis of amplified DNA polymorphisms resulted from PCR (polymerase chain reaction) analysis. The sampled plants consisted of 38 individuals in 5 taxa. Only 10 primers out of 62 primers (60 random [10-mer] primers, two 15-mer [M13 core sequence, and (GGAT) sequence]) tested gave rise to polymorphisms in all of the tested plants, producing 176 DAN fragments amplified. Intraspecific polymorphisms found in each taxa showed intraspecies constancy (31.1-61.1%) in the banding patterns of individual plants: Saussurea sp. 31.1%, 15 bands, Aster tataricus, 40.9%, 18 bands, A. scaber. 38.5%, 15 bands. Synurus deltoides, 34.7%, 17 bands, and Ligularia fischeri, 61.1%, 22 brands, respectively. All five species were well classified from each other at the 0.93 level of similarity index value. Intraspecific and interspecific variations were appeared at the levels ranging from 0.62 to 0.99. Based on these results, our PCR analyses support the previous data derived from external morphology of the 5 edible mountain vegetables, but very low levels o intraspecific variations were detected in all of these taxa.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.61-68
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• 2008

Acrylamide is present as a contaminant in heated food products, predominantly from the precursor asparagine. Nonanchored inter simple sequence repeats (ISSRs) are arbitrary multiloci markers produced by PCR amplification with a microsatellite primer. In order to assess the feasibility of microsatellite primers as markers for DNA damage, the study was conducted on common bean (Phaseolus vulgaris L.) exposed to different concentrations of acrylamide. Polymorphisms were abundant among plant samples treated with acrylamide in comparison to control (untreated one) tested with 4- tri-nucleotide, 2 tetra-nucleotide, and 3- dinucelotide primers. The primer (CCG)4 was the best tested primer to generate polymorphism between the DNA of plants treated or not by acrylamide. Polymorphisms became evident as the presence and absence of DNA fragments in treated samples compared with the untreated one. The highest number of DNA variation on ISSR patterns was observed at the micromollar concentrations of acrylamide. Acrylamide was able to induce DNA damage in non concentration-dependent manner with effectiveness at micromollar concentrations. This study demonstrated that ISSR markers can be highly reliable for identification of DNA damage induced by acrylamide.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.98-105
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• 2007

Phylogenetic relationships in Korean watermelons were evaluated by genetic similarity coefficients using 15 SSR(simple sequence repeat), 14 SCAR(sequence characterized amplified region) and 14 CAPS(sequence characterized amplified region) markers. The SSR markers were selected from previously reported melon and watermelon SSRs through testing polymorphisms within a set of commercial $F_1$ varieties. The SCAR and CAPS markers were developed from polymorphic AFLP(amplified fragment length polymorphism) markers between inbred lines 'BN4001' and 'BN4002'. From the AFLP analysis, 105 polymorphic fragments were identified between the inbred lines using 1,440 primer combinations of EcoRI+CNNN and XbaI+ANNN. Based on the sequencing data of these polymorphic fragments, we synthesized sequence specific primer pairs and detected clear and reliable polymorphisms in 27 primer pairs by indels(insertion/deletion) or RFLP(restriction fragment length polymorphism). A total of 43 sequence-based PCR markers were obtained and polymorphic information content(PIC) was analyzed to measure the informativeness of each marker in watermelon varieties. The average PIC value of SCAR markers was 0.41, which was similar to that of SSR markers. Genetic diversity was also estimated by using these markers to assess the phylogenetic relationships among commercial varieties of watermelon. These markers differentiated 26 Korean watermelon varieties into two major phylogenetic groups, but this grouping was not significantly correlated with their morphological and physiological characteristics. The mean genetic similarity was 66% within the complete set of 26 commercial varieties. In addition, these sequence-based PCR markers were reliable and useful to identify cultivars and genotypes of watermelon.

• Development and Reproduction
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• v.18 no.4
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• pp.275-286
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• 2014

To successful molecular breeding, identification and functional characterization of breeding related genes and development of molecular breeding techniques using DNA markers are essential. Although the development of a useful marker is difficult in the aspect of time, cost and effort, many markers are being developed to be used in molecular breeding and developed markers have been used in many fields. Single nucleotide polymorphisms (SNPs) markers were widely used for genomic research and breeding, but has hardly been validated for screening functional genes in olive flounder. We identified single nucleotide polymorphisms (SNPs) from expressed sequence tag (EST) database in olive flounder; out of a total 4,327 ESTs, 693 contigs and 514 SNPs were detected in total EST, and these substitutions include 297 transitions and 217 transversions. As a result, 144 SNP markers were developed on the basis of 514 SNP to selection of useful gene region, and then applied to each of eight wild and culture olive flounder (total 16 samples). In our experimental result, only 32 markers had detected polymorphism in sample, also identified 21 transitions and 11 transversions, whereas indel was not detected in polymorphic SNPs. Heterozygosity of wild and cultured olive flounder using the 32 SNP markers is 0.34 and 0.29, respectively. In conclusion, we identified SNP and polymorphism in olive flounder using newly designed marker, it supports that developed markers are suitable for SNP detection and diversity analysis in olive flounder. The outcome of this study can be basic data for researches for immunity gene and characteristic with SNP.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.71-77
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• 2012

The objective of this study is to develop the gene based sequence tagged site (STS) markers in wheat. The euchromatin enriched genomic library was constructed and the STS primer sets were designed using gene based DNA sequence. The euchromatin enriched genomic (EEG) DNA library in wheat was constructed using the $Mcr$A and $Mcr$BC system in $DH5{\alpha}$ cell. The 2,166 EEG colonies have been constructed by methylated DNA exclusion. Among the colonies, 606 colonies with the size between 400 and 1200 bp of PCR products were selected for sequencing. In order to develop the gene based STS primers, blast analysis comparing between wheat genetic information and rice genome sequence was employed. The 227 STS primers mainly matched on $Triticum$ $aestivum$ (hexaploid), $Triticum$ $turgidum$ (tetraploid), $Aegilops$ (diploid), and other plants. The polymorphisms were detected in PCR products after digestion with restriction enzymes. The eight STS markers that showed 32 polymorphisms in twelve wheat genotypes were developed using 227 STS primers. The STS primers analysis will be useful for generation of informative molecular markers in wheat. Development of gene based STS marker is to identify the genetic function through cloning of target gene and find the new allele of target trait.

• Journal of Microbiology
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• v.41 no.2
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• pp.129-136
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• 2003

The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMPI) exhibits considerable sequence heterogeneity among EBV isolates. Seven distinct EBV strains have been defined based on sequence polymorphisms in the LMPI gene, which are designated China 1, China 2, China 3, Alaskan, Mediterranean, NC, and the B95-8 strains. In this study, we analyzed a 30-bp deletion and sequence variations in the carboxy-terminal region of the LMPl gene in 12 EBV isolates from spontaneous lym-phoblastoid cell lines derived from individuals with non-EBV associated cancers in Korea. Eleven of the 12 isolates showed a 30-bp deletion spanning LMPI amino acids 342 to 353, suggesting a high prevalence of the LMPI 30-bp deletion variant among EBV isolates in Korea. In addition, all 12 isolates had a 15-bp common deletion in the 33-bp repeat region and multiple base-pair changes relative to the prototype B95-8 EBV strain along with variations in the number of the 33-bp repeats. The bp changes at positions 168746, 168694, 168687, 168395, 168357, 168355, 168631, 168320, 168308, 168295, and 168225 were highly conserved among the isolates. Comparative analysis of sequence change patterns in the LMPI carboxy-terminal coding region identified nine 30-bp deletion variants as China 1, two deletion variants as a possible interstrain between the Alaskan and China 1 strains, and a single undeleted variant as a possible variant of the Alaskan strain. These results suggest the predominance of the China 1 EBV strain in the Korean population.

• BMB Reports
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• v.39 no.2
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• pp.183-188
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• 2006

Using the Phred/Phrap/Polyphred/Consed pipeline established in the National Livestock Research Institute of Korea, we predicted candidate coding single nucleotide polymorphisms (cSNPs) from 7,600 expressed sequence tags (ESTs) derived from three cDNA libraries (liver, M. longissimus dorsi, and intermuscular fat) of Hanwoo (Korean native cattle) steers. From the 7,600 ESTs, 829 contigs comprising more than two EST reads were assembled using the Phrap assembler. Based on the contig analysis, 201 candidate cSNPs were identified in 129 contigs, in which transitions (69%) outnumbered transversions (31%). To verify whether the predicted cSNPs are real, 17 SNPs involved in lipid and energy metabolism were selected from the ESTs. Twelve of these were confirmed to be real while five were identified as artifacts, possibly due to expressed sequence tag sequence error. Further analysis of the 12 verified cSNPs was performed using the program BLASTX. Five were identified as nonsynonymous cSNPs, five were synonymous cSNPs, and two SNPs were located in 3'-UTRs. Our data indicated that a relatively high SNP prediction rate (71%) from a large EST database could produce abundant cSNPs rapidly, which can be used as valuable genetic markers in cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1529-1535
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• 2006

Leptin has been investigated as a candidate gene for fat characteristics in beef cattle. Previously, we have reported 57 sequence variants discovered in Korean cattle (Bos Taurus coreanae). In this study, we examined the association between polymorphisms of leptin and carcass traits (cold carcass weight (CWT) and marbling score (Marb)) in Korean cattle. Among 57 polymorphisms, 11 common polymorphic sites were genotyped in our beef cattle (n = 437). Statistical analysis revealed that one single nucleotide polymorphism in coding exon (c.+411T>C (A137A)) showed a significant association with the yield trait, CWT. The C-bearing genotypes (CC or CT) of c.+411T>C (A137A) showed the higher CWT (p = 0.006). c.+150C>G (S50S) also showed a significant association with the quality trait, Marb (p = 0.01). Our findings suggest that polymorphisms in leptin might be one of the important genetic factors that influence carcass yield and quality in beef cattle, especially in CWT and Marb.