• Korean Journal of Microbiology
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• v.35 no.2
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• pp.121-127
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• 1999

An effective computer program for assembling fragments in DNA sequencing has been developed. The program, called SeqEditor (Sequence Editor), is usable on the pcrsonal computer systems of MS-Widows which is the mosl popular operating system in Korea. It c'm recd several sequence file formats such as GenBak, FASTA, and ASCII. In the SeqEditor program, a dynamic programming algorihm is applied to compute the maximalscoring overlapping alignment between each pjlr of fragments. A novel feature of the program is that SeqEdilor implemnents interaclive operation with a graphical user interface. The performance lests of the prograln 011 fragmen1 data from 16s and 18s rDNA sequencing pi-ojects produced saiisIactory results. This program may be useful to a person who has work of time with large-scale DNA sequencing projects.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.58-63
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• 1998

Fragment assembly problem is to reconstruct DNA sequence contigs from a collection of fragment sequences. We have developed an efficient X-window program, XFAP, for assembling DNA fragments. In the XFAP, the dimer frequency comparison method is used to quickly eliminate pairs of fragments that can not overlap. This method takes advantage of the difference of dimer frequencies within the minimum acceptable overlap length in each fragment pair. Hirschberg algorithm is applied to compute the maximal-scoring overlapping alignment in linear space. The perfomance of XFAP was tested on a set of DNA fragment sequences extracted from long DNA sequences of GenBank by a fragmentation program and showed a great improvement in execution time, especially as the number of fragments increases.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2329-2334
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• 2006

In this paper, we proposed a method complementing failure of combining DNA fragments, defect of conventional contig assembly programs. In the proposed method, very long DNA sequence data are made into a prototype of fragment of about 700 bases that can be analyzed by automatic sequence analyzer at one time, and then matching ratio is calculated by comparing a standard prototype with 3 fragmented clones of about 700 bases generated by the PCR method. In this process, the time for calculation of matching ratio is reduced by Compute Agreement algorithm. Two candidates of combined fragments of every prototype are extracted by the degree of overlapping of calculated fragment pairs, and then degree of combination is decided using a fuzzy reasoning method that utilizes the matching ratios of each extracted fragment, and A, C, G, T membership degrees of each DNA sequence, and previous frequencies of each A, C, G, T. In this paper. DNA sequence combination is completed by the iteration of the process to combine decided optimal test fragments until no fragment remains. For the experiments, fragments or about 700 bases were generated from each sequence of 10,000 bases and 100,000 bases extracted from 'PCC6803', complete protein genome. From the experiments by applying random notations on these fragments, we could see that the proposed method was faster than FAP program, and combination failure, defect of conventional contig assembly programs, did not occur.

• Journal of Life Science
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• v.25 no.3
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• pp.357-367
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• 2015

With the ongoing development of next-generation sequencing (NGS) platforms and advancements in the latest bioinformatics tools at an unprecedented pace, the ultimate goal of sequencing the human genome for less than $1,000 can be feasible in the near future. The rapid technological advances in NGS have brought about increasing demands for statistical methods and bioinformatics tools for the analysis and management of NGS data. Even in the early stages of the commercial availability of NGS platforms, a large number of applications or tools already existed for analyzing, interpreting, and visualizing NGS data. However, the availability of this plethora of NGS data presents a significant challenge for storage, analyses, and data management. Intrinsically, the analysis of NGS data includes the alignment of sequence reads to a reference, base-calling, and/or polymorphism detection, de novo assembly from paired or unpaired reads, structural variant detection, and genome browsing. While the NGS technologies have allowed a massive increase in available raw sequence data, a number of new informatics challenges and difficulties must be addressed to improve the current state and fulfill the promise of genome research. This review aims to provide an overview of major NGS technologies and bioinformatics tools for NGS data analyses.

• Korea Multimedia Society
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• v.12 no.2
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• pp.21-27
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• 2008

• Applied Biological Chemistry
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• v.39 no.5
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• pp.355-360
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• 1996

In vitro-tested ribozyme against synthesized cucumber mosaic virus (CMV) RNA (Agric. Chem. & Biotech. 37:56-63(1994)) was expressed in tobacco plant to develop virus resistant plants. The ribozyme sequence was linked to cauliflower mosaic virus 35S promoter and nopaline synthase(nos) terminator and this chimeric 35S-ribozyme-nos gene was sequenced. The sequenced chimeric gene was transferred to Agrobacterium tumefaciens LBA4404 using tri-parental mating system. The E. coli HB101 containing chimeric gene was incubated with E. coli HB101(pRK2073) as a helper and Agrobacterium tumefaciens LBA4404. Then Agrobacterium cells containing the ribozyme construct was cocultivated with tobacco leaf pieces. Ten different plants were regenerated from kanamycin containing MS medium. The presence of the ribozyme construct in the transgenic tobacco plants was confirmed by polymerase chain reaction (PCR). Seven different transgenic plants in ten different kanamycin resistant plants showed the expected size (570 base pairs) of 35S-ribozyme-nos gene fragment. Total RNAs were isolated from four different transgenic plants and separated on a 1% agarose gel containing formamide. Northern hybridization with 35S-ribozyme-nos gene fragment as a probe indicated that ribozyme transcripts may be degraded tv nuclease. Therefore, nuclease-resistant ribozymes are needed for the development of virus-resistant transgenic plants using ribozymes.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.30-33
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• 1997

About 250 bp ura5 gene (Orotate phosphoribosyl transferase) fragment was cloned from genomic DNA of entomopathogenic fungus Metarhizium anisopliae by using PCR method. Entire nucleotide sequences of cloned DNA fragment were determined and analysed as compared with other fungus ura5 genes. The amino acid sequence deduced from the nucleotide sequence showed 85.5% homology to ura5 protein of Trichoderma reesei. Using this 250 bp PCR fragment we have isolated full ura5 gene of M. anisopliae by genomic Southern hybridization and the isolated 4.4 kb DNA fragments were mapped by restrictional enzyme.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.34-34
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• 2003

한국산 선발계통 및 일본산 양식계통과 이들 두 계통간 잡종 참돔 집단의 유전적 특성을 분석하기 위하여, RAPD (Random Amplified Polymorphic DNA) marker를 탐색하였다. 10개의 염기로 이루어진 200개의 random primer 분석을 통하여 polymorphic pattern을 나타내는 23개의 random primer를 선발하였으며, 각 primer의 재현성을 확인하였다. 이들 중 OPA-11 primer는 크기가 각각 600 bp, 650 bp 및 750 bp 인 3개의 DNA 단편에 의하여 4개의 genotype을 나타냈으며, 각 genotype의 빈도는 집단간차이를 보였고, 한국산 선발계통 집단에서는 4개의 genotype이 모두 발견되는 반면, 일본산 양식계통 및 일본산 양식계통을 포함한 교배집단에서는 특정 genotype만 발견되었다. OPA-11 primer 유래의 polymorphic DNA 단편을 cloning하고 염기서열을 결정하였으며, SCAR (Sequence Characterized Amplified Region) primer를 제작하고 분석하였다. 본 연구는 참돔집단의 유전적 특성 파악 및 집단 구별에 RAPD marker를 활용하였으며, 참돔 육종시 형질 및 기능관련 DNA marker 탐색에 적용하기 위하여, 이후의 연구에서는 SCAR과 RFLP 분석에 RAPD marker를 이용하여 100% 정확도를 갖는 RFLP maker를 찾고, MAS (Marker-Assisted Selection)에 적용하고자 한다.

• Journal of Intelligence and Information Systems
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• v.13 no.2
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• pp.55-68
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• 2007

DNA sequence alignment algorithms in computational molecular biology have been improved by diverse methods. In this paper, we proposed a DNA sequence alignment algorithm utilizing quality information and a fuzzy inference method utilizing characteristics of DNA sequence fragments and a fuzzy logic system in order to improve conventional DNA sequence alignment methods using DNA sequence quality information. In conventional algorithms, DNA sequence alignment scores were calculated by the global sequence alignment algorithm proposed by Needleman-Wunsch applying quality information of each DNA fragment. However, there may be errors in the process for calculating DNA sequence alignment scores in case of low quality of DNA fragment tips, because overall DNA sequence quality information are used. In the proposed method, exact DNA sequence alignment can be achieved in spite of low quality of DNA fragment tips by improvement of conventional algorithms using quality information. And also, mapping score parameters used to calculate DNA sequence alignment scores, are dynamically adjusted by the fuzzy logic system utilizing lengths of DNA fragments and frequencies of low quality DNA bases in the fragments. From the experiments by applying real genome data of NCBI (National Center for Biotechnology Information), we could see that the proposed method was more efficient than conventional algorithms using quality information in DNA sequence alignment.

• Journal of Life Science
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• v.2 no.2
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• pp.108-119
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• 1992

근년에 개발된 효소적인 DNA증폭법을 이용하면 일차구조상의 단편적인 정보만 알면 단 수시간내 해석에 필요한 양의 DNA가 증폭되어 cDNA의 염기배열결정의 신속화, 간편화가 가능하게 되었다. 그러므로 유전자증폭법으로써 PCR법에 관해 기술한다. 그리고 리보좀 RNA는 분자시계로서 생물의 계통을 논하는 데에 있어서는 최적의 조건을 갖춘 고분자화합물이다. 이에 PCR법을 이용한 16S like 리보좀DNA의 증폭법을 다루고, PCR증폭산물의 염기배열결정법에 대해 서술한다. 또한 인위적인 leading error 등을 배제하고 신속한 자동해독과 시간적인 절약이 자동 DNA sequencer의 개발과 시판으로 가능하게 되어 cDNA의 형광색소표식 염기배열결정법에 대해서도 서술한다.