• Genomics & Informatics
• /
• v.18 no.1
• /
• pp.3.1-3.8
• /
• 2020

Patient-derived xenograft (PDX) mouse models are frequently used to test the drug efficacy in diverse types of cancer. They are known to recapitulate the patient characteristics faithfully, but a systematic survey with a large number of cases is yet missing in lung cancer. Here we report the comparison of genomic characters between mouse and patient tumor tissues in lung cancer based on exome sequencing data. We established PDX mouse models for 132 lung cancer patients and performed whole exome sequencing for trio samples of tumor-normal-xenograft tissues. Then we computed the somatic mutations and copy number variations, which were used to compare the PDX and patient tumor tissues. Genomic and histological conclusions for validity of PDX models agreed in most cases, but we observed eight (~7%) discordant cases. We further examined the changes in mutations and copy number alterations in PDX model production and passage processes, which highlighted the clonal evolution in PDX mouse models. Our study shows that the genomic characterization plays complementary roles to the histological examination in cancer studies utilizing PDX mouse models.

• Journal of Plant Biotechnology
• /
• v.33 no.3
• /
• pp.153-160
• /
• 2006

Brassica rape is an important species used as a vegetable, oil, and fodder worldwide. It is related phylogenically to Arabidopsis thaliana, which has already been fully sequenced as a model plant. The 'Multinational Brassica Genome Project (MBGP)'was launched by the international Brassica community with the aim of sequencing the whole genome of B. rapa in 2003 on account of its value and the fact that it has the smallest genome among the diploid Brassica. The genome study was carried out not only to know the structure of genome but also to understand the function and the evolution of the genes comprehensively. There are two mapping populations, over 1,000 molecular markers and a genetic map, 2 BAC libraries, physical map, a 22 cDHA libraries as suitable genomic materials for examining the genome of B. rapa ssp. pekinensis Chinese cabbage. As the first step for whole genome analysis, 220,000 BAC-end sequences of the KBrH and KBrB BAC library are achieved by cooperation of six countries. The results of BAC-end sequence analysis will provide a clue in understanding the structure of the genome of Brassica rapa by analyzing the gene sequence, annotation and abundant repetitive DHA. The second stage involves sequencing of the genetically mapped seed BACs and identifying the overlapping BACs for complete genome sequencing. Currently, the second stage is comprises of process genetic anchoring using communal populations and maps to identify more than 1,000 seed BACs based on a BAC-to-BAC strategy. For the initial sequencing, 629 seed BACs corresponding to the minimum tiling path onto Arabidopsis genome were selected and fully sequenced. These BACs are now anchoring to the genetic map using the development of SSR markers. This information will be useful for identifying near BAC clones with the seed BAC on a genome map. From the BAC sequences, it is revealed that the Brassica rapa genome has extensive triplication of the DNA segment coupled with variable gene losses and rearrangements within the segments. This article introduces the current status and prospective of Korea Brassica Genome Project and the bioinformatics tools possessed in each national team. In the near future, data of the genome will contribute to improving Brassicas for their economic use as well as in understanding the evolutional process.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.10a
• /
• pp.14-27
• /
• 2003

The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.11a
• /
• pp.272-273
• /
• 2007

현대 유전체학 기술의 진보는 생물학적으로 중요한 의미를 갖는 생물들의 유전체 서열의 규명 genome sequencing)에 힘입은 바 크다. 기존의 유전체 서열결정법은 주로 염기변이율이 낮은 생물들에 초점을 맞추어 왔다. 하지만 염기변이율이 높은 생물들의 유전체 염기서열을 결정할 필요가 높아짐에 따라 이를 위한 방법론에 대한 연구가 활발히 진행되고 있다. 염기변이율이 높은 생물들의 이배체 (diploid) 유전체 서열이 효과적으로 결정될 수 있을 경우 기존의 유전체 서열비교의 방법론에도 변화가 요청되고 있는 실정이다. 기존의 유전체 서열비교 (whole-genome alignment) 방법론은 반수체 (haploid) 유전체들의 서열비교을 위해 개발되었지만, 염기변이율이 높은 생물들의 유전체 서열비교에는 반수체 유전체들 비교에 특화된 도구들이 필요하다. 또한 현재 서열비교를 시각화하는 소프트웨어들도 반수체 유전체 비교를 위해 개발된 실정이다. 본 논문의 목표는 이배체 유전체 서열을 비교하는 방법론을 개발을 용이하기위해 이배체 유전체의 서열을 생성하는 도구를 개발하는 것이다. 개발된 도구는 실제 일어날 수 있는 염기변이와 genomic rearrangement를 사용자의 입력을 받아 다수의 생물들의 유전체 서열을 생성해 낸다. 이를 통해 이배체 유전체 서열을 비교하는 도구의 개발을 용이하게 하는데 초첨을 맞추고 있다.

• Genomics & Informatics
• /
• v.15 no.1
• /
• pp.48-50
• /
• 2017

Tumor tissues from biopsies or surgery are major sources for the next generation sequencing (NGS) study, but these procedures are invasive and have limitation to overcome intratumor heterogeneity. Recent studies have shown that driver alterations in tumor tissues can be detected by liquid biopsy which is a less invasive technique capable of both capturing the tumor heterogeneity and overcoming the difficulty in tissue sampling. However, it is still unclear whether the driver alterations in liquid biopsy can be detected by targeted NGS and how those related to the tissue biopsy. In this study, we performed whole-exome sequencing for a breast cancer tissue and identified PTEN p.H259fs*7 frameshift mutation. In the plasma DNA (liquid biopsy) analysis by targeted NGS, the same variant initially identified in the tumor tissue was also detected with low variant allele frequency. This mutation was subsequently validated by digital polymerase chain reaction in liquid biopsy. Our result confirm that driver alterations identified in the tumor tissue were detected in liquid biopsy by targeted NGS as well, and suggest that a higher depth of sequencing coverage is needed for detection of genomic alterations in a liquid biopsy.

• Genomics & Informatics
• /
• v.11 no.1
• /
• pp.7-14
• /
• 2013

As the International Human Epigenome Consortium (IHEC) launched officially at the 2010 Washington meeting, a giant step toward the conquest of unexplored regions of the human genome has begun. IHEC aims at the production of 1,000 reference epigenomes to the international scientific community for next 7-10 years. Seven member institutions, including South Korea, Korea National Institute of Health (KNIH), will produce 25-200 reference epigenomes individually, and the produced data will be publically available by using a data center. Epigenome data will cover from whole genome bisulfite sequencing, histone modification, and chromatin access information to miRNA-seq. The final goal of IHEC is the production of reference maps of human epigenomes for key cellular status relevant to health and disease.

• Genomics & Informatics
• /
• v.11 no.4
• /
• pp.218-223
• /
• 2013

The rapid advances in genetic knowledge and technology raise various, sometimes unprecedented, ethical dilemmas in the scientific community as well as the public realm. To deal with these dilemmas, the international community has prepared and issued ethical standards in various formats. In this review, seven international standards regarding genetics and genomics will be briefly introduced in chronological order. Critical reflections on them will not be provided in this review, and naturally, they have their own problems and shortcomings. However, a common set of the principles expressed in them will be highlighted here, because they are still relevant, and many of them will be more relevant in the future. Some of the interesting contents will be selected and described. After that, the morality of one recent event related to whole-genome sequencing and person-identifiable genetic data will be explored based on those international standards.

• Journal of Animal Science and Technology
• /
• v.63 no.1
• /
• pp.191-193
• /
• 2021

Lactococcus lactis is a fermentative lactic acid bacterium that is used extensively in food fermentations. The L. lactis strain K_LL005 was isolated from the grasshopper (Oxya chinensis sinuosa) gut in Korea. In this study, we reported the complete genome sequence of Lactococcus lactis K_LL005. The final complete genome assembly consist of one circular chromosome (2,375,093 bp) with an overall guanine + cytosine (G + C) content of 35.0%. Annotation results revealed 2,281 protein-coding sequences (CDSs), 19 rRNAs, and 68 tRNA genes. Lactococcus lactis K_LL005 has a gene encoding xylose metabolism such as xylR, xylA, and xylB (xylRAB).

• Mycobiology
• /
• v.49 no.1
• /
• pp.86-88
• /
• 2021

The monokaryotic strain, Schizophyllum commune strain IUM1114-SS01, was generated from a basidiospore of dikaryotic parental strain IUM1114. It even showed the decolorizing activities for several textile dyes much better than its parental strain. Based on the results of a single-molecule real-time sequencing technology, we present the draft genome of S. commune IUM1114-SS01, comprising 41.1 Mb with GC contents of the genome were 57.44%. Among 13,380 protein-coding genes, 534 genes are carbon hydrate-active enzyme coding genes.