• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.683-688
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• 2006

We have developed a program for generating shotgun data sets from known genome sequences. Generation of synthetic data sets by computer program is a useful alternative to real data to which students and researchers have limited access. Uniformly-distributed-sampling clones that were adopted by previous programs cannot account for the real situation where sampled reads tend to come from particular regions of the target genome. To reflect such situation, a probabilistic model for biased sampling distribution was developed by using an experimental data set derived from a microbial genome project. Among the experimental parameters tested (varied fragment or read lengths, chimerism, and sequencing error), the extent of sequencing error was the most critical factor that hampered sequence assembly. We propose that an optimum sequencing strategy employing different insert lengths and redundancy can be established by performing a variety of simulations.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2000년도 추계학술발표논문집 (상)
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• pp.207-210
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• 2000

지금까지 인간이나 다른 생물체의 전체 유전체 염기서열을 밝혀내는 작업은 크게 세가지 방법으로 진행되었다. Clone-by-clone approach, sequence tagged connector approach, random shotgun approach(1)가 그것인데 마지막의 random shotgun approach는 fragment assembly problem을 비롯한 여러 가지 전산학적인 문제들을 수반한다. 이 논문은 저자들의 국내 최초로 미생물체의 전체 염기서열을 random shotgun approach를 이용하여 밝혀낸 경험을 바탕으로 그에 따르는 문제인 fragment assembly problem에 대해 소개하고 그에 수반되는 몇 가지 전산학적인 문제와 몇 가지 해결책에 대해 설명하려 한다.

• Genomics & Informatics
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• 제21권4호
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• pp.49.1-49.11
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• 2023

Recent advances in sequencing technologies and platforms have enabled to generate metagenomics sequences using different sequencing platforms. In this study, we analyzed and compared shotgun metagenomic sequences generated by HiSeq3000 and BGISEQ-500 platforms from 12 sediment samples collected across the Norwegian coast. Metagenomics DNA sequences were normalized to an equal number of bases for both platforms and further evaluated by using different taxonomic classifiers, reference databases, and assemblers. Normalized BGISEQ-500 sequences retained more reads and base counts after preprocessing, while a slightly higher fraction of HiSeq3000 sequences were taxonomically classified. Kaiju classified a higher percentage of reads relative to Kraken2 for both platforms, and comparison of reference database for taxonomic classification showed that MAR database outperformed RefSeq. Assembly using MEGAHIT produced longer assemblies and higher total contigs count in majority of HiSeq3000 samples than using metaSPAdes, but the assembly statistics notably improved with unprocessed or normalized reads. Our results indicate that both platforms perform comparably in terms of the percentage of taxonomically classified reads and assembled contig statistics for metagenomics samples. This study provides valuable insights for researchers in selecting an appropriate sequencing platform and bioinformatics pipeline for their metagenomics studies.

• The Plant Pathology Journal
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• 제16권2호
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• pp.83-89
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• 2000

No Abstract.See Full-text

• Genomics & Informatics
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• 제7권1호
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• pp.46-48
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• 2009

Finishing is the most time-consuming step in sequencing, and many genome projects are left unfinished due to complex repeat regions. Here, we have developed BACContigEditor, a prototype shotgun sequence finishing tool. It is essentially an editor that visualizes assemblies of shotgun sequence fragment reads as gapped multiple alignments. The program offers some flexibility that is needed to rapidly resolve complex regions within a working session. The sole purpose of the release is to promote collaborative creation of extensible software for fragment assembly editors, foster collaborative development, and reduce barriers to initial tool development effort. We describe our software architecture and identify current challenges. The program is available under an Open Source license.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.175-182
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• 2023

Antibiotics have been used in livestock production for not only treatment but also for increasing the effectiveness of animal feed, aiding animal growth, and preventing infectious diseases at the time when immunity is lowered due to stress. South Korea and the EU are among the countries that have prohibited the use of antibiotics for growth promotion in order to prevent indiscriminate use of antibiotics, as previous studies have shown that it may lead to increase in cases of antibiotic-resistant bacteria. Therefore, this study evaluated the number of antibiotic resistance genes in piglets staging from pre-weaning to weaning. Fecal samples were collected from 8 piglets just prior to weaning (21 d of age) and again one week after weaning (28 d of age). Total DNA was extracted from the 200 mg of feces collected from the 8 piglets. Whole metagenome shotgun sequencing was carried out using the Illumina Hi-Seq 2000 platform and raw sequence data were imported to Metagenomics Rapid Annotation using Subsystem Technology (MG-RAST) pipeline for microbial functional analysis. The results of this study did not show an increase in antibiotic-resistant bacteria although confirmed an increase in antibiotic-resistant genes as the consequence of changes in diet and environment during the experiment.

• Genomics & Informatics
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• 제2권4호
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• pp.174-179
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• 2004

We developed various plasmid cloning vectors that are useful in the construction of genomic and shotgun libraries. Two medium copy vectors, pCUGlblu21 (pCb21) and pAGlblu21 (pAb21), which are resistant to kanamycin ($Km^R$) and chloramphenicol ($Cam^R$), respectively, are useful for cloning DNA inserts ranging from 5kb to 15kb. Two high copy vectors, pCUGlblu31 (pCb31) and pAGlblu31 (pAb31), containing $Km^R$ and $Cam^R$, respectively, are useful for DNA inserts less than 5kb. These vectors are well adapted for large-scale genome sequencing projects by providing choice of copy number and selectable marker. The small vector size is another advantage of these vectors. All vectors contain lacZa including multicloning sites that originated from pBluscriptllsk- for easy cloning and sequencing. Two medium copy vectors contain unique and rare cutting Swal (ATTTAAAT) restriction enzyme sites for easy determination of insert size. We developed two combined vectors, pC21A31 and pC31A21, which are combinations of (pCb21 + pAb31) and (pCb31 + pAb21), respectively. These two vectors provide four choices of vectors such as $Km^R$ and medium, $Cam^R$ and high, $Cam^R$ and medium, and $Km^R$ and high copy vectors by restriction enzyme cutting, dephosphorylation, and gel purification. These vectors were successfully applied to high throughput shotgun sequencing of rice, tomato, and brassica BAC clones. With an example of extremely biased hydro sheared 3 kb shotgun library of a tomato BAC clone, which is originated from cytogenetically defined peri-centromeric region, we suggest the utility of an additional 10 kb library for sequence assembly of the difficult-to-assemble BAC clone.

• 분석과학
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• 제31권2호
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• pp.65-70
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• 2018

이 연구에서는 대규모 병렬형 염기서열 분석 (massively parallel sequencing)에 적용할 샷건 라이브러리 (shotgun library)를 성공적으로 제작하기 위해 두 가지 유형의 고대 DNA (ancient DNA, aDNA) 분리 방법을 비교하였다. 헝가리 선사 시대 늑골 뼈 시료로 실리카 현탁액을 이용한 추출법과 Amicon Ultracel-15 10K 초원심 분리 장치(Millipore)를 이용한 추출법을 비교하였다. 약 150 mg의 뼛가루에서 각각의 방법으로 3 회 반복 추출한 후 이중 가닥 DNA (double stranded DNA, ds DNA)의 양을 측정하였다. 초원심분리 농축 방법은 실리카 현탁액을 사용하는 것보다 더 빠르고, 더 쉬운 공정이며 약 11 배 높은 DNA 회수율을 나타냈다. 또한 초원심 분리 장치로 획득한 DNA 주형은 실리카 현탁액으로 획득한 것보다 샷건 라이브러리가 훨씬 성공적으로 만들어졌다. 두 종류의 aDNA 추출 방법을 비교한 본 연구는 Amicon 장치를 사용하는 분리법이 시간의 절약, 단순한 프로세스 및 높은 효율 등의 장점을 지니고 있음을 보여주었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1999년도 임시총회 및 추계 학술발표회
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• pp.33.1-33
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• 1999

• Journal of Genetic Medicine
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• 제12권2호
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• pp.66-71
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• 2015

Down syndrome screening with cell-free DNA (cfDNA) in the maternal plasma has recently received much attention in the prenatal diagnostic field. Indeed, a large amount of evidence has already accumulated to show that screening tests with cfDNA are more sensitive and specific than conventional maternal serum and/or ultrasound screening. Globally, more than 1,000,000 of these noninvasive prenatal tests (NIPTs) have been performed to date. There are several different methods for NIPTs that are currently commercially available, including shotgun massively parallel sequencing, targeted massively parallel sequencing, and single nucleotide polymorphism (SNP)-based methods. All of these methods have their own advantages and disadvantages. In this review, I will focus specifically on the SNP-based NIPT.