• Journal of Information Processing Systems
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• 제3권1호
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• pp.38-42
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• 2007

Microarray data includes tens of thousands of gene expressions simultaneously, so it can be effectively used in identifying the phenotypes of diseases. However, the retrieval of functional information from a large corpus of gene expression data is still a time-consuming task. In this paper, we propose an efficient method for identifying functional categories of differentially expressed genes from a micro-array experiment by using Gene Ontology (GO). Our method is as follows: (1) The expression data set is first filtered to include only genes with mean expression values that differ by at least 3-fold between the two groups. (2) The genes are then ranked based on the t-statistics. The 100 most highly ranked genes are selected as informative genes. (3) The t-value of each informative gene is imposed as a score on the associated GO terms. High-scoring GO terms are then listed with their associated genes and represent the functional category information of the micro-array experiment. A system called HMDA (Hallym Micro-array Data analysis) is implemented on publicly available micro-array data sets and validated. Our results were also compared with the original analysis.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.161-164
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• 2005

Data mining techniques can be applied to identify patterns of interest in the gene expression data. One goal in mining gene expression data is to determine how the expression of any particular gene might affect the expression of other genes. To find relationships between different genes, association rules have been applied to gene expression data set [1]. A notable limitation of association rule mining method is that only the association in a single profile experiment can be detected. It cannot be used to find rules across different condition profiles or different time point profile experiments. However, with the appearance of time-series microarray data, it became possible to analyze the temporal relationship between genes. In this paper, we analyze the time-series microarray gene expression data to extract the sequential patterns which are similar to the association rules between genes among different time points in the yeast cell cycle. The sequential patterns found in our work can catch the associations between different genes which express or repress at diverse time points. We have applied sequential pattern mining method to time-series microarray gene expression data and discovered a number of sequential patterns from two groups of genes (test, control) and more sequential patterns have been discovered from test group (same CO term group) than from the control group (different GO term group). This result can be a support for the potential of sequential patterns which is capable of catching the biologically meaningful association between genes.

• Genomics & Informatics
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• 제16권4호
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• pp.36.1-36.3
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• 2018

Next generation sequencing (NGS), a high-throughput DNA sequencing technology, is widely used for molecular biological studies. In NGS, RNA-sequencing (RNA-Seq), which is a short-read massively parallel sequencing, is a major quantitative transcriptome tool for different transcriptome studies. To utilize the RNA-Seq data, various quantification and analysis methods have been developed to solve specific research goals, including identification of differentially expressed genes and detection of novel transcripts. Because of the accumulation of RNA-Seq data in the public databases, there is a demand for integrative analysis. However, the available RNA-Seq data are stored in different formats such as read count, transcripts per million, and fragments per kilobase million. This hinders the integrative analysis of the RNA-Seq data. To solve this problem, we have developed a web-based application using Shiny, COEX-seq (Convert a Variety of Measurements of Gene Expression in RNA-Seq) that easily converts data in a variety of measurement formats of gene expression used in most bioinformatic tools for RNA-Seq. It provides a workflow that includes loading data set, selecting measurement formats of gene expression, and identifying gene names. COEX-seq is freely available for academic purposes and can be run on Windows, Mac OS, and Linux operating systems. Source code, sample data sets, and supplementary documentation are available as well.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1439-1448
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• 2022

Background: We investigated the feasibility of in vitro radiosensitivity prediction with gene expression using deep learning. Methods: A microarray gene expression of the National Cancer Institute-60 (NCI-60) panel was acquired from the Gene Expression Omnibus. The clonogenic surviving fractions at an absorbed dose of 2 Gy (SF2) from previous publications were used to measure in vitro radiosensitivity. The radiosensitivity prediction model was based on the convolutional neural network. The 6-fold cross-validation (CV) was applied to train and validate the model. Then, the leave-one-out cross-validation (LOOCV) was applied by using the large-errored samples as a validation set, to determine whether the error was from the high bias of the folded CV. The criteria for correct prediction were defined as an absolute error<0.01 or a relative error<10%. Results: Of the 174 triplicated samples of NCI-60, 171 samples were correctly predicted with the folded CV. Through an additional LOOCV, one more sample was correctly predicted, representing a prediction accuracy of 98.85% (172 out of 174 samples). The average relative error and absolute errors of 172 correctly predicted samples were 1.351±1.875% and 0.00596±0.00638, respectively. Conclusion: We demonstrated the feasibility of a deep learning-based in vitro radiosensitivity prediction using gene expression.

• Journal of Plant Biotechnology
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• 제36권4호
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• pp.384-391
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• 2009

Previously, two events (H15 and B20) of transgenic pepper (Capsicum annuum L.) that enhanced resistance to Cucumber mosaic virus (CMV) by the introduction of CMV coat protein (CP) gene were constructed. Presently, a single copy number of the CP gene was revealed in H15 and B20 by Southern blot. To predict possible unintended effects due to transgene insertion in an endogenous gene, we carried out sequencing of the 5'-flanking region of the CP gene and a Blastbased search. The results revealed that insertion of the transgene into genes encoding putative proteins may occur in the H15 and B20 transgenic event. Mutiplex polymerase chain reaction (PCR) for simultaneous detection and identification of transgenic pepper was conducted with a set of nine primers. Both transgenic event were differentiated from non-transgenic event by the presence of 267 bp and 430 bp PCR products indicative of CP gene specific primer pairs and primer pairs targeting the CP gene and 35S promoter. H15 and B20 uniquely possessed a 390 bp and 596 bp PCR product, respectively. The presence of a 1115 bp product corresponding to intrinsic pepper actin gene confirmed the use of pepper DNA as the PCR template. The primer set and PCR conditions used presently may allow the accurate and simple identification of CMV resistant transgenic pepper.

• 생명과학회지
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• 제21권5호
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• pp.626-630
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• 2011

세계적 멸종위기종인 따오기(Nipponia nippon)는 2008년 10월에 중국에서 1쌍이 도입된 후 한국최초로 인공번식에 성공하였다. 본 연구는 따오기의 sex-related gene과 Chromodomain Helicase DNA Binding Protein gene (CHD gene)을 가지고 polymerase chain reaction (PCR)을 수행하여 새로 태어난 따오기 유조의 성별을 확인하고자 하였다. 본 연구에서는 따오기의 성별 확인을 위해 PCR후 제한효소의 처리 방법과 P2과 P8를 이용한 PCR 방법을 실시하였을 때 더 정확한 결과가 나타남을 알 수 있었다. 그리고 CHD gene의 염기서열을 선행연구와 비교해 본 결과, 암컷의 염기서열에서 1~2 base pairs 차이가 나타남을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.641-646
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• 2012

In our recent report on gene expression in gastric cancer we identified the endo-sulfatase Sulf-1 gene to be up-regulated in gastric tumors relative to apparently normal (AN), and paired normal (PN) gastric tissue samples. In the present report we investigate the protein expression levels of Sulf-1 gene in gastric tumors, AN and PN samples using tissue microarray (TMA) and immunohistochemistry. Expression data was collected from two sets of TMA's containing replicate sections of tissue samples. Scoring data from TMA set-1 revealed a significant difference in Sulf-1 immunoreactivity between tumors and "normals" (PN and AN) (p-value = 0.001928). Also, Sulf-1 expression in tumors was also significantly different from either PN (p-value = 0.019) or AN (p-value = 0.006) samples. Similar results were obtained from analysis of scoring data from the second set of arrays. Comparison of mRNA expression and protein expression in gastric tumor tissues revealed that in 6/20 (30%) tumor samples showed up-regulated protein expression concordant with over-expression of mRNA. However, a discord with mRNA being over-expressed relative to down regulated protein expression was observed in majority 14/20 (70%) of tumor samples. Our study indicates down regulation of Sulf-1 protein expression in gastric tumors relative to PN and AN samples which is discordant with mRNA over-expression seen in tumors.

• Journal of Ginseng Research
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• 제44권3호
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• pp.519-526
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• 2020

Background: Bisphenol A (BPA), known as an endocrine disruptor, is widely used in the world. BPA is reported to cause inflammation-related diseases. Korean Red Ginseng (KRG) has been used safely in human for a long time for the treatment of diverse diseases. KRG has been reported of its mitigating effect on menopausal symptoms and suppress adipose inflammation. Here, we investigate the protective effect of orally administered KRG on the impacts of BPA in the liver and uterus of menopausal mice model. Methods: The transcriptome analysis for the effects of BPA on mice liver was evaluated by Gene Expression Omnibus (GEO) database-based data (GSE26728). In vivo assay to evaluate the protective effect of KRG on BPA impact in ovariectomized (OVX) mice were designed and analyzed by RNA sequencing. Results: We first demonstrated that BPA induced 12 kinds of gene set in the liver of normal mice. The administration of BPA and KRG did not change body, liver, and uterine weight in OVX mice. KRG downregulated BPA-induced inflammatory response and chemotaxis-related gene expression. Several gene set enrichment analysis (GSEA)-derived inflammatory response genes increased by BPA were inhibited by KRG in OVX mice. Conclusion: Our data suggest that BPA has commonly influenced inflammatory response effects on both normal and OVX mice. KRG protects against BPA impact of inflammatory response and chemotaxis in OVX mouse models. Our comparative analysis will provide new insight into the efficacy of KRG on endocrine disrupting chemicals and OVX mouse.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.1-8
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• 2011

Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

• Molecules and Cells
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• 제26권6호
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• pp.611-615
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• 2008

DNA methylation is an epigenetic mechanism for gene silencing. In Arabidopsis, MET1 is the primary DNA methyltransferase that maintains CG DNA methylation. Plants having an overall reduction of MET1 activity, caused by a met1 mutation or a constitutively expressed MET1 antisense gene, display genome hypomethylation, inappropriate gene and transposon transcription, and developmental abnormalities. However, the effect of a transient reduction in MET1 activity caused by inhibiting MET1 expression in a restricted set of cells is not known. For this reason, we generated transgenic plants with a MET1 antisense gene fused to the DEMETER (DME) promoter (DME:MET1 a/s). Here we show that DME is expressed in leaf primordia, lateral root primoridia, in the region distal to the primary root apical meristem, which are regions that include proliferating cells. Endogenous MET1 expression was normal in organs where the DME:MET1 a/s was not expressed. Although DME promoter is active only in a small set of cells, these plants displayed global developmental abnormalities. Moreover, centromeric repeats were hypomethylated. The developmental defects were accumulated by the generations. Thus, not maintaining CG methylation in a small population of proliferating cells flanking the meristems causes global developmental and epigenetic abnormalities that cannot be rescued by restoring MET1 activity. These results suggest that during plant development there is little or no short-term molecular memory for reestablishing certain patterns of CG methylation that are maintained by MET1. Thus, continuous MET1 activity in dividing cells is essential for proper patterns of CG DNA methylation and development.