• Development and Reproduction
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• v.18 no.1
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• pp.1-11
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• 2014

Early growth response 1 (Egr1) is a zinc-finger transcription factor to direct second-wave gene expression leading to cell growth, differentiation and/or apoptosis. While it is well-known that Egr1 controls transcription of an array of targets in various cell types, downstream target gene(s) whose transcription is regulated by Egr1 in the uterus has not been identified yet. Thus, we have tried to identify a list of potential target genes of Egr1 in the uterus by performing multi-step in silico promoter analyses. Analyses of mRNA microarray data provided a cohort of genes (102 genes) which were differentially expressed (DEGs) in the uterus between Egr1(+/+) and Egr1(-/-) mice. In mice, the frequency of putative EGR1 binding sites (EBS) in the promoter of DEGs is significantly higher than that of randomly selected non-DEGs, although it is not correlated with expression levels of DEGs. Furthermore, EBS are considerably enriched within -500 bp of DEG's promoters. Comparative analyses for EBS of DEGs with the promoters of other species provided power to distinguish DEGs with higher probability as EGR1 direct target genes. Eleven EBS in the promoters of 9 genes among analyzed DEGs are conserved between various species including human. In conclusion, this study provides evidence that analyses of mRNA expression profiles followed by two-step in silico analyses could provide a list of putative Egr1 direct target genes in the uterus where any known direct target genes are yet reported for further functional studies.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.1
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• pp.42-53
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• 2020

Objective: Recently, microRNA (miRNA) has been identified both as a powerful regulator involved in various biological processes through the regulation of numerous genes and as an effective biomarker for the prediction and diagnosis of various disease states. The objective of this study was to identify and validate miRNAs and their target genes involved in inflammation in placental tissue. Methods: Microarrays were utilized to obtain miRNA and gene expression profiles from placentas with or without inflammation obtained from nine normal pregnant women and 10 preterm labor patients. Quantitative real-time polymerase chain reaction and Western blots were performed to validate the miRNAs and differentially-expressed genes in the placentas with inflammation. Correlations between miRNA and target gene expression were confirmed by luciferase assays in HTR-8/SVneo cells. Results: We identified and validated miRNAs and their target genes that were differentially expressed in placentas with inflammation. We also demonstrated that several miRNAs (miR-371a-5p, miR-3065-3p, miR-519b-3p, and miR-373-3p) directly targeted their target genes (LEF1, LOX, ITGB4, and CD44). However, some miRNAs and their direct target genes showed no correlation in tissue samples. Interestingly, miR-373-3p and miR-3065-3p were markedly regulated by lipopolysaccharide (LPS) treatment, although the expression of their direct targets CD44 and LOX was not altered by LPS treatment. Conclusion: These results provide candidate miRNAs and their target genes that could be used as placental biomarkers of inflammation. These candidates may be useful for further miRNA-based biomarker development.

• Molecules and Cells
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• v.39 no.5
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• pp.395-402
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• 2016

Identifying Hoxc8 target genes is at the crux of understanding the Hoxc8-mediated regulatory networks underlying its roles during development. However, identification of these genes remains difficult due to intrinsic factors of Hoxc8, such as low DNA binding specificity, context-dependent regulation, and unknown cofactors. Therefore, as an alternative, the present study attempted to test whether the roles of Hoxc8 could be inferred by simply analyzing genes frequently coexpressed with Hoxc8, and whether these genes include putative target genes. Using archived gene expression datasets in which Hoxc8 was differentially expressed, we identified a total of 567 genes that were positively coexpressed with Hoxc8 in at least four out of eight datasets. Among these, 23 genes were coexpressed in six datasets. Gene sets associated with extracellular matrix and cell adhesion were most significantly enriched, followed by gene sets for skeletal system development, morphogenesis, cell motility, and transcriptional regulation. In particular, transcriptional regulators, including paralogs of Hoxc8, known Hox co-factors, and transcriptional remodeling factors were enriched. We randomly selected Adam19, Ptpn13, Prkd1, Tgfbi, and Aldh1a3, and validated their coexpression in mouse embryonic tissues and cell lines following $TGF-{\beta}2$ treatment or ectopic Hoxc8 expression. Except for Aldh1a3, all genes showed concordant expression with that of Hoxc8, suggesting that the coexpressed genes might include direct or indirect target genes. Collectively, we suggest that the coexpressed genes provide a resource for constructing Hoxc8-mediated regulatory networks.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.22-26
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• 2002

There are a number of ways in which environmental microbiology and microbial ecology will benefit from DNA micro array technology. These include community genome arrays, SSU rDNA arrays, environmental functional gene arrays, population biology arrays, and there are clearly more different applications of microarray technology that can be applied to relevant problems in environmental microbiology. Two types of the applications, bacterial identification chip and functional gene detection chip, will be presented. For the bacterial identification chip, a new approach employing random genome fragments that eliminates the disadvantages of traditional DNA-DNA hybridization is proposed to identify and type bacteria based on genomic DNA-DNA similarity. Bacterial genomes are fragmented randomly, and representative fragments are spotted on a glass slide and then hybridized to test genomes. Resulting hybridization profiles are used in statistical procedures to identify test strains. Second, the direct binding version of microarray with a different array design and hybridization scheme is proposed to quantify target genes in environmental samples. Reference DNA was employed to normalize variations in spot size and hybridization. The approach for designing quantitative microarrays and the inferred equation from this study provide a simple and convenient way to estimate the target gene concentration from the hybridization signal ratio.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.116-116
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• 2017

Low-temperature is one of the environmental stress factors that affect plant growth and development and consequently limit crop productivity. The control of seed germination under low-temperature is organized by many genes which are called quantitative trait loci (QTLs). High germination rate for low-temperature is an important factor of growing rice. Previously, we identified a major QTL controlling low-temperature germinability in rice using 96 introgression lines (ILs) derived from a cross between Oryza rufipogon (Rufi) and the Korean japonica cultivar, 'Hwaseongbyeo (HS)'. A $BC_3F_7$ line (TR5) showed better low-temperature germinability than its recurrent parent. TR5 was crossed with HS to develop a segregating F2:3 populations for the target QTL. Six SSR markers polymorphic between HS and Rufi were used to screen and fine map the qLTG1. The qLTG1 on chromosome 1, which accounted for 55.5% of the total phenotypic variation, confirmed that Rufi allele enhanced the low-temperature germinability. Intervals between markers CRM16 and CRM15, four candidate genes were identified. The identified candidate genes, which are encoded by a protein of unknown function, showed their direct involvement on seed germination at low-temperature. To identify genes targeted by qLTG1, we investigated the expression profiles of these candidate genes and germination behavior of qLTG1 under different stress conditions and compared to HS, Rufi, and TR5 at $13{\pm}2^{\circ}C$ for 3 days after incubation. Furthermore, transgenic rice plants will also be developed to conduct a detailed investigation on low-temperature germinability. Hence, the QTL for low-temperature germinability would be useful in rice breeding programs especially in the development of lines possessing low-temperature germinability.

• BMB Reports
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• v.51 no.10
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• pp.481-483
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• 2018

Glioblastoma (GBM) is the most common and aggressive form of human adult brain malignancy. The identification of the cell of origin harboring cancer-driver mutations is the fundamental issue for understanding the nature of GBM and developing the effective therapeutic target. It has been a long-term hypothesis that neural stem cells in the subventricular zone (SVZ) might be the origin-of-cells in human glioblastoma since they are known to have life-long proliferative activity and acquire somatic mutations. However, the cell of origin for GBM remains controversial due to lack of direct evidence thereof in human GBM. Our recent study using various sequencing techniques in triple matched samples such as tumor-free SVZ, tumor, and normal tissues from human patients identified the clonal relationship of driver mutations between GBM and tumor-free SVZ harboring neural stem cells (NSCs). Tumor-free SVZ tissue away from the tumor contained low-level GBM driver mutations (as low as 1% allelic frequency) that were found in the dominant clones in its matching tumors. Moreover, via single-cell sequencing and microdissection, it was discovered that astrocyte-like NSCs accumulating driver mutations evolved into GBM with clonal expansion. Furthermore, mutagenesis of cancer-driving genes of NSCs in mice leads to migration of mutant cells from SVZ to distant brain and development of high-grade glioma through the aberrant growth of oligodendrocyte precursor lineage. Altogether, the present study provides the first direct evidence that NSCs in human SVZ is the cell of origin that develops the driver mutations of GBM.