• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.1 no.2
• /
• pp.39-50
• /
• 2008

Developing computational methods for identifying cell cycle-regulated genes has been one of important topics in systems biology. Most of previous methods consider the periodic characteristics of expression signals to identify the cell cycle-regulated genes. However, we assume that cell cycle-regulated genes are relatively active having relatively many interactions with each other based on the underlying cellular network. Thus, we are motivated to apply the theory of multivariate phase synchronization to the cell cycle expression analysis. In this study, we apply the method known as "Self-Organizing Maps with statistical Phase Synchronization (SOMPS)", which is the combination of self-organizing map and multivariate phase synchronization, producing several subsets of genes that are expected to have interactions with each other in their subset (Kim, 2008). Our evaluation experiments show that the SOMPS algorithm is able to detect cell cycle-regulated genes as much as one of recently reported method that performs better than most existing methods.

• Korean Journal of Breeding Science
• /
• v.41 no.2
• /
• pp.73-83
• /
• 2009

To investigate genes related to vernalization and cold- resistance in barley (Hordeum vulgare L. cv. Nagaoka), differentially expressed genes were identified from cold-resistant barley leaves with suppression subtractive hybridization (SSH) and Northern blot analyses. The nucleotide and the deduced amino acid sequences of the putative gene products were compared. The bvrn-7 showed high homology(84%) with gene related to vernalization, and the bvrn-3, bvrn-12, bvrn-28, bvrn-29 and bvrn-36 related to cold-resistant genes had high identity of 88~98% with low temperature-induced genes. The results indicate that the 6 genes were closely related to vernalization and cold-resistance during low temperature treatment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.10
• /
• pp.1496-1511
• /
• 2015

The study aimed to compare the necrotic enteritis (NE)-induced transcriptome differences between the spleens of Marek's disease resistant chicken line 6.3 and susceptible line 7.2 co-infected with Eimeria maxima/Clostridium perfringens using RNA-Seq. Total RNA from the spleens of two chicken lines were used to make libraries, generating 42,736,296 and 42,617,720 usable reads, which were assembled into groups of 29,897 and 29,833 mRNA genes, respectively. The transcriptome changes were investigated using the differentially expressed genes (DEGs) package, which indicated 3,255, 2,468 and 2,234 DEGs of line 6.3, line 7.2, and comparison between two lines, respectively (fold change ${\geq}2$, p<0.01). The transcription levels of 14 genes identified were further examined using qRT-PCR. The results of qRT-PCR were consistent with the RNA-seq data. All of the DEGs were analysed using gene ontology terms, the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the DEGs in each term were found to be more highly expressed in line 6.3 than in line 7.2. RNA-seq analysis indicated 139 immune related genes, 44 CD molecular genes and 150 cytokines genes which were differentially expressed among chicken lines 6.3 and 7.2 (fold change ${\geq}2$, p<0.01). Novel mRNA analysis indicated 15,518 novel genes, for which the expression was shown to be higher in line 6.3 than in line 7.2 including some immune-related targets. These findings will help to understand host-pathogen interaction in the spleen and elucidate the mechanism of host genetic control of NE, and provide basis for future studies that can lead to the development of marker-based selection of highly disease-resistant chickens.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.11
• /
• pp.4499-4505
• /
• 2014

Glioblastoma, the most aggressive and malignant form of glioma, appears to be resistant to various chemotherapeutic agents. Hence, approaches have been intensively investigated to targeti specific molecular pathways involved in glioblastoma development and progression. Aloe emodin is believed to modulate the expression of several genes in cancer cells. We aimed to understand the molecular mechanisms underlying the therapeutic effect of Aloe emodin on gene expression profiles in the human U87 glioblastoma cell line utilizing microarray technology. The gene expression analysis revealed that a total of 8,226 gene alterations out of 28,869 genes were detected after treatment with $58.6{\mu}g/ml$ for 24 hours. Out of this total, 34 genes demonstrated statistically significant change (p<0.05) ranging from 1.07 to 1.87 fold. The results revealed that 22 genes were up-regulated and 12 genes were down-regulated in response to Aloe emodin treatment. These genes were then grouped into several clusters based on their biological functions, revealing induction of expression of genes involved in apoptosis (programmed cell death) and tissue remodelling in U87 cells (p<0.01). Several genes with significant changes of the expression level e.g. SHARPIN, BCAP31, FIS1, RAC1 and TGM2 from the apoptotic cluster were confirmed by quantitative real-time PCR (qRT-PCR). These results could serve as guidance for further studies in order to discover molecular targets for the cancer therapy based on Aloe emodin treatment.

• Journal of Plant Biotechnology
• /
• v.44 no.2
• /
• pp.115-124
• /
• 2017

Cytoplasmic male sterility (CMS) is a maternally inherited trait leading to loss of the ability to produce fertile pollen and is extensively used in hybrid crop breeding. Ogura-CMS was originally generated by insertion of orf138 upstream of atp8 in the radish mitochondrial genome and transferred to Brassica crops for hybrid breeding. Gene expression changes by dysfunctional mitochondria in Ogura-CMS result in pollen developmental defects, but little is known about gene expression patterns in vegetative tissue. To examine the interaction between nuclear and organellar regulation of gene expression, microarray and subsequent gene expression experiments were conducted with leaves of $F_1$ hybrid Chinese cabbage derived from self-incompatible (SI) or Ogura-CMS parents (Brassica rapa ssp. pekinensis). Out of 24,000 genes deposited on a KBGP24K microarray, 66 genes were up-regulated and 26 genes were down-regulated by over 2.5 fold in the CMS leaves. Up-regulated genes included stress-response genes and mitochondrial protein genes, while genes for ascorbic acid biosynthesis and thylakoid proteins were down-regulated. Most of the major component genes for light reactions of photosynthesis were highly expressed in leaves of both SI and CMS plants, but most of the corresponding proteins were found to be greatly reduced in leaves of CMS plants, indicating posttranscriptional regulation. Reduction in thylakoid proteins and chlorophylls led to reduction in photosynthetic efficiency and chlorosis of Ogura-CMS at low temperatures. This research provides a foundation for studying chloroplast function regulated by mitochondrial signal and for using organelle genome introgression in molecular breeding.

• Molecular & Cellular Toxicology
• /
• v.1 no.3
• /
• pp.149-156
• /
• 2005

Di (n-ethylhexyl) phthalate (DEHP) is thought to mimic estrogens in their action, and are called endocrine disrupting chemicals. DEHP is used in numerous consumer products, especially those made of flexible polyvinyl chloride and have been reported to be weakly estrogenic. In this study, DEHP were tested for estrogenic properties in vitro models and with microarray analysis. First, the E-screen assay was used to measure the proliferation of DEHP in MCF-7 cells, a human breast cancer cell line. DEHP induced an increase in MCF-7 cell proliferation at concentration of $10^{-4}M$. Second, we carried out a microarray analysis of MCF-7 cells treated with DEHP using human c-DNA microarray including 401 endocrine system related genes. Of the genes analyzed, 60 genes were identified showing significant changes in gene expression resulting from DEHP. Especially, 4 genes were repressed and 4 genes were induced by DEHP compared to $17{\beta}-estradiol$. Among these genes, trefoil factor 3 (intestinal), breast cancer 1, early onset and CYP1B1 are involved in estrogen metabolism and regulation. Therefore it suggests that these genes may be associated with estrogenic effect of the DEHP on transcriptional level. The rationale is that, as gene expression is a sensitive endpoint, alterations of these genes may act as useful biomarkers to define more precisely the nature and level of exposure to kinds of phthalates.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.72.2-73
• /
• 2003

We found a soybean (Glycine max) cultivar 561 that was strongly resistant to a virulent bacterial strain of a Pseudomonas spp. Further identification revealed that the Pseudomonas spp. was a strain of Pseudomonas aeruginosa. Furthermore we identified specific genes involved in the resistance of soybean 561 and analyzed the pattern of gene expression against the Pseudomonas infection using differential-display reverse transcription PCR (DDRT-PCR). More than 126 cDNA fragments representing mRNAs were induced within 48 hours of bacteria inoculation. Among them, 28 cDNA fragments were cloned and sequenced. Twelve differentially displayed clones with open reading frames had unknown functions. Sixteen selected cDNA clones were homologous to known genes in the other organisms. Some of the identified cDNAs were pathogenesis-related genes (PR genes) and PR-like genes. These cDNAs included a putative calmodulin-binding protein, an endo-1,3-1,4-b-D-glucanase, a b-1,3-endoglucanase, a b-1,3-exoglucanase, a phytochelatin synthetase-like gene, a thiol pretense, a cycloartenol synthase, and a putative receptor-like sorineithreonine protein kinase. Among them, we found that four genes were putative pathogenesis-related genes (PR) induced significantly by the p. aeruginosa infection. These included a calmodulin-binding protein gene, a b-1,3-endoglucanase gene, a receptor-like sorine/threonine protein kinase gene, and pS321 (unknown function). These results suggest that the differentially expressed genes may mediate the strong resistance of soybean 561 to Pseudomonas aeruoginosa.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.871-884
• /
• 2009

Gene expression profiling is a useful tool for identifying critical genes and pathways in metabolism. The objective of this study was to determine the major differences in the expression of genes associated with metabolism and metabolic regulation in liver and mammary tissues of lactating cows. We used the Michigan State University bovine metabolism (BMET) microarray; previously, we have designed a bovine metabolism-focused microarray containing known genes of metabolic interest using publicly available genomic internet database resources. This is a high-density array of 70mer oligonucleotides representing 2,349 bovine genes. The expression of 922 genes was different at p<0.05, and 398 genes (17%) were differentially expressed by two-fold or more with 222 higher in liver and 176 higher in mammary tissue. Gene ontology categories with a high percentage of genes more highly expressed in liver than mammary tissues included carbohydrate metabolism (glycolysis, glucoenogenesis, propanoate metabolism, butanoate metabolism, electron carrier and donor activity), lipid metabolism (fatty acid oxidation, chylomicron/lipid transport, bile acid metabolism, cholesterol metabolism, steroid metabolism, ketone body formation), and amino acid/nitrogen metabolism (amino acid biosynthetic process, amino acid catabolic process, urea cycle, and glutathione metabolic process). Categories with more genes highly expressed in mammary than liver tissue included amino acid and sugar transporters and MAPK, Wnt, and JAK-STAT signaling pathways. Real-time PCR analysis showed consistent results with those of microarray analysis for all 12 genes tested. In conclusion, microarray analyses clearly identified differential gene expression profiles between hepatic and mammary tissues that are consistent with the differences in metabolism of these two tissues. This study enables understanding of the molecular basis of metabolic adaptation of the liver and mammary gland during lactation in bovine species.

• Bioinformatics and Biosystems
• /
• v.1 no.1
• /
• pp.67-72
• /
• 2006

The aim of this paper is to discuss the effect of missing values in detecting differentially expressed genes in a cDNA microarray experiment in the context of a one sample problem. We conducted a cDNA micro array experiment to detect differentially expressed genes for the metastasis of colorectal cancer based on twenty patients who underwent liver resection due to liver metastasis from colorectal cancer. Total RNAs from metastatic liver tumor and adjacent normal liver tissue from a single patient were labeled with cy5 and cy3, respectively, and competitively hybridized to a cDNA microarray with 7775 human genes. We used $M=log_2(R/G)$ for the signal evaluation, where Rand G denoted the fluorescent intensities of Cy5 and Cy3 dyes, respectively. The statistical problem comprises a one sample test of testing E(M)=0 for each gene and involves multiple tests. The twenty cDNA microarray data would comprise a matrix of dimension 7775 by 20, if there were no missing values. However, missing values occur for various reasons. For each gene, the no missing proportion (NMP) was defined to be the proportion of non-missing values out of twenty. In detecting differentially expressed (DE) genes, we used the genes whose NMP is greater than or equal to 0.4 and then sequentially increased NMP by 0.1 for investigating its effect on the detection of DE genes. For each fixed NMP, we imputed the missing values with K-nearest neighbor method (K=10) and applied the nonparametric t-test of Dudoit et al. (2002), SAM by Tusher et al. (2001) and empirical Bayes procedure by $L\ddot{o}nnstedt$ and Speed (2002) to find out the effect of missing values in the final outcome. These three procedures yielded substantially agreeable result in detecting DE genes. Of these three procedures we used SAM for exploring the acceptable NMP level. The result showed that the optimum no missing proportion (NMP) found in this data set turned out to be 80%. It is more desirable to find the optimum level of NMP for each data set by applying the method described in this note, when the plot of (NMP, Number of overlapping genes) shows a turning point.

• Molecular & Cellular Toxicology
• /
• v.4 no.3
• /
• pp.183-191
• /
• 2008

Volatile organic compounds (VOCs) are common constituents of cleaning and degreasing agents, paints, pesticides, personal care products, gasoline and solvents. And VOCs are evaporated at room temperature and most of them exhibit acute and chronic toxicity to human. Benzene is the most widely used prototypical VOC and the toxic mechanisms of them are still unclear. The multi-step process of toxic mechanism can be more fully understood by characterizing gene expression changes induced in cells by toxicants. In this study, DNA microarray was used to monitor the expression levels of genes in HepG2 cells and HL-60 cells exposed to the benzene on IC20 and IC50 dose respectively. In the clustering analysis of gene expression profiles, although clusters of HepG2 and HL-60 cells by benzene were divided differently, expression pattern of many genes observed similarly. We identified 916 up-regulated genes and 1,144 down-regulated genes in HepG2 cells and also 1,002 up-regulated genes and 919 down-regulated genes in HL-60 cells. The gene ontology analysis on genes expressed by benzene in HepG2 and HL-60 cells, respectively, was performed. Thus, we found some principal pathways, such as, focal adhesion, gap junction and signaling pathway in HepG2 cells and toll-like receptor signaling pathway, MAPK signaling pathway, p53 signaling pathway and neuroactive ligand-receptor interaction in HL-60 cells. And we also found 16 up-regulated and 14 down-regulated commonly expressed total 30 genes that belong in the same biological process like inflammatory response, cell cycle arrest, cell migration, transmission of nerve impulse and cell motility in two cell lines. In conclusion, we suggest that this study is meaningful because these genes regarded as strong potential biomarkers of benzene independent of cell type.