• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.231-237
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• 2007

Exposure to DNA-damaging agents can elicit a variety of stress-related responses that may alter the expression of genes associated with numerous biological pathways. We used 19 k whole human genome chip to detect gene expression profiles and potential signature genes in human normal hepatocytes (THLE-3) by treatment of five direct acting mutagens, furylfuramide (AF-2), N-nitroso-N-methylurea (MNU), methylmethanesulfonate (MMS), 4-nitroquinoline-N-oxide (4-NQO) and 2-nitrofluorene (2NF) of the $IC_{20}$ concentration for 3 h. Fifty one up-regulated common genes and 45 down-regulated common genes above 1.5-fold by five direct-acting mutagens were identified by clustering analysis. Many of these changed genes have some association with apoptosis, control of cell cycle, regulation of transcription and signal transduction. Genes related to these functions, as TP73L, E2F5, MST016, SOX5, MAFB, LIF, SII3, TFIIS, EMR1, CYTL1, CX3CR1 and RHOH are up-regulated. Down-regulated genes are ALOX15B, xs155, IFITM1, BATF, VAV2, CD79A, DCDC2, TNFSF8 and KOX8. We suggest that gene expression profiling on mutagens by toxicogenomic analysis affords promising opportunities to reveal potential new mechanistic markers of genotoxicity.

• Interdisciplinary Bio Central
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• v.2 no.4
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• pp.13.1-13.8
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• 2010

The National BioResource Project of Japan is a governmental project to promote domestic/international research activities using biological resources. The project has 27 biological resources including three cereal resources. The core center and sub-center which historically collected the cereal resources were selected for each cereal program. These resources are categorized into several different types in the project; germplasm, genetic stocks, genome resources and database information. Contents of rice resources are wild species, local varieties in East and Southwest Asia & wild relatives, MNU-induced chemical mutant lines, marker tester lines, chromosome substitution lines and other experimental lines. Contents of wheat resources are wild strains, cultivated strains, experimental lines, rye wild and cultivated strains; EST clones and full-length cDNA clones. Contents of barley resources are cultivar and experimental lines, core collection, EST/cDNA clones, BAC clones, their filters and superpool DNA. Each resource is accessible from the online database to see the contents and information about the resources. Links to the genome information and genomic tools are also important function of each database. The major contents and some examples are presented here.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.8
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• pp.856-862
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• 2015

Tidal current energy is an important alternative energy resource among the various ocean energy resources available. The tidal currents in the South-Western sea of Korea can be utilized for the development of tidal current power generation. Tidal power generation can be beneficial for many fishing nurseries and nearby islands in the southwest region of Korea. Moreover, tidal power generation is necessary for promoting energy self-sufficient islands. As tidal currents are always available, power generation is predictable; thus, tidal power is a reliable renewable energy resource. The selection of an appropriate hydrofoil is important for designing a tidal current turbine. This study concentrates on the selection and numerical analysis of four different hydrofoils (MNU26, NACA63421, DU91_W2_250, and DU93_W_210LM). Blade element momentum theory is used for configuring the design of a 50 W class turbine rotor blade. The optimized blade geometry is used for computational fluid dynamics (CFD) analysis with hexahedral numerical grids. Among the four blades, NACA63421 blade showed the maximum power coefficient of 0.45 at a tip speed ratio of 6. CFD analysis is used to investigate the power coefficient, pressure coefficient, and streamline distribution of a 50 W class horizontal axis tidal current turbine for different hydrofoils.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2000.09a
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• pp.26-26
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• 2000

The consumption of cruciferous vegetables such as cabbage and broccoli have been shown to have a chemopreventive effect in human and in experimental animals. Indole-3-carbinol (I3C), one component of cruciferous vegetables, has been shown to exert its chemopreventive effect in liver, colon and mammary tissue before or concurrent exposure of carcinogen, but in some reports, there have been several evidence that consumption of I3C after carcinogen treatment induced tumor promotion in some tissues. There have been no reports about the effect of I3C after carcinogen exposure in N-Nitroso-N-methylurea (MNU)-induced mammary tumor model of rats. (omitted)

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.23-27
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• 2010

The objective of this study was to map the gene for reduced embryo size in rice using DNA markers. The reduced embryo size mutant was induced from N-methyl-N-nitrosourea (MNU) treated Taichung 65. Genetic analysis revealed that the phenotype of the reduced embryo was controlled by a single recessive gene, designated as re-1. For mapping the gene controlling embryo size, an $F_2$ population was developed from a cross between the Korean Tongil-type, Milyang 23 (Oryza sativa ssp. indica) and the mutant. The ratio of $F_2$ seeds nearly fitted to 3:1 ratio, indicating that this phenotype was controlled by a single recessive gene. Bulked sergeant analysis was performed with SSR markers. The gene for the reduced embryo size was detected on chromosome 1. The gene was further mapped between two SSR markers, RM315 and RM265 on chromosome 1 (approximately 1.5 Mb interval). The linked markers will facilitate selection of this grain character in a breeding program and provide the foundation for positional cloning of this gene.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.414-421
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• 1998

In order to compare the suppressive effect of quercetin and its glycosides, such as quercitrin (quercetin-3-rhamnoside), isoquercitrin (quercetin-3-glucoside), hyperin (querceti n-3-galactoside)and rutin (quercetin-3-rhamnosyl glucoside), on the genotocicity by benzo(a)pyrene(B(a)P), in vitro sister chromatid exchange(SCE) test using mouse spleen lymphocytes and in vivo micronucleus test using mouse peripheral blood were performed. B(a)P-induced SCEs in vitro were slightly decreased by the simultaneous treatment of quercetin and its glycosides, although there was no significant decrease. On the other hand, MNU induced micronucleated reticulocytes(MNRL7s) in vivo were significantly decreased with a dose-dependent manner in all compounds tested. However, there were no differences between quercetin aglycone and glycosides in the suppressive effects under experimental condition of this study. To elucidate, the action mechanism of quercetin aglycone and its glycosides against B(a)P-induced genotoxicity, the assay of DNA binding with B(a)P was studied. Quercetin aglycone and its glycosides inhibited B(a)P metabolism in the presence of S-9 mix and decreased the B(a)P/DNA binding in the calf thymus DNA with S-9 mix. These results suggest that antigenotoxicity of quercetin antiglycosides on B(a)P-induced genotoxicity is due to decrease of DNA binding with B(a)P through the inhibition of metabolism with B(a)P in the calf thymus DNA. Therefore, quercetin and its glycosides may act as an antigenotoxicity agent and may be useful as a chemopreventive agent of polycyclic aromaic hydrocarbons like B(a)P.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.257-265
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• 2012

This study was carried out to evaluate growth, morphological characteristics, and sugar content among fifty six blackberry (Rubus fructicosus) genotypes derived from gamma-ray treatment (fifty two lines), MNU treatments (three lines), and cross breed R. fructicosus${\times}$R. parvifolius(one line). While 56 genotypes had similar stem diameter with origin variety, the most of mutants showed reduced leaf size. Also, they showed a wide range of variation in fruit size and one hundred fruit weight compared with origin variety. In fruit size and sugar content, two mutant lines showed large fruit sizes and ten mutant lines showed 20% higher sugar content than the original variety. In the correlation analysis, positive relationships were determined between sugar content and stem diameter, fruit length, leaf wide and fruit length/fruit wide ratio. However, leaf length/leaf wide ratio showed a negative correlation with sugar content. The results will be used as fundamental data for Rubus fructicosus breeding program.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.1-10
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• 2010

Five mutants were investigated at the molecular level to determine the factors responsible for mutated endosperm types. They were classified as high (HA) or low amylose (LA) phenotypes based on the amylose content in endosperm. The five were previously produced from Ilpum and Shindongjin cultivar treated with N-methyl-N-nitrosourea and gamma-ray irradiation, respectively. Analysis of the genomic structure and expression of Granule-bounded Starch Synthase I (GBSSI) genes revealed that mutants generally showed a higher incidence of nucleotide transition than transversion, and the $A:T{\rightarrow}G:C$ transition was particularly prevalent. The rates of nucleotide substitution in HA mutants were generally higher than those in the LA mutants, leading to higher substitutions of amino acid in the HA mutants. Neither nucleotide substitutions interfering with intron splicing or causing early termination of protein translation were found, nor any large-sized deletions or additions were found in all the mutants. In principle, amylose content can be regulated by three factors: internal alterations of GBSSI protein, the strength of gene expression, and other unknown external factors. Our results indicate that the endosperm mutants from Shindongjin arose from internal alterations of GBSSI proteins, which may be the result of amino acid substitutions. On the other hand, the Ilpum mutants might be principally caused by the alteration of gene expression level. Analysis of another three glutinous cultivars revealed that the major factor leading to glutinous phenotypes is the 23-bp duplicative motif (5'-ACGGGTTCCAGGGCCTCAAGCCC-3') commonly found in exon 2, which results in the premature termination of protein translation leading to the production of a non-functional GBSSI enzyme.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.375-382
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• 2011

A chemical, MNU-induced hulless barley mutant line designated as 'Mutant 98 (M98)' was developed from a Korean hulless waxy barley cultivar, 'Chalssalbori'. The objective of the study was to determine the genetic basis of 'M98' and the possibility of using 'M98' as breeding parent to improve lysine level. Compared to 'Chalssalbori', 'M98' had large embryo and higher lysine content in both the embryo and endosperm. Significantly different lysine content in 'M98' and the other high-lysine barley mutant stocks was observed for two years. However, the genotype by year interaction was not significant. 'M98' was higher than the other high-lysine barley mutant stocks in the percentage of lysine of total amino acid composition (0.75%). The trait of shrunken endosperm of 'M98', which was typical in the high-lysine mutants, was inherited by a single recessive gene. Based on seed morphology and lysine content of $F_1$ seeds, 'M98' had a genetically different gene from the other high-lysine mutants for shrunken endosperm. Segregation of $F_2$ for plump/shrunken endosperm did not fit the expected ratio of Mendelian inheritance except for only one cross combination (GSHO1784 (lys1)/M98). The amino acid analysis of $F_5$ and $F_6$ progenies from the cross between 'M98' and 'Chalssalbori' revealed that the attempt to increase the range of lysine content of plump lines did not go beyond the limit of the average high-lysine barley germplasm.

• BMB Reports
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• v.36 no.1
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• pp.82-94
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• 2003

Although debates still exist whether Helicobacter pylori infection is really class I carcinogen or not, H. pylori has been known to provoke precancerous lesions like gastric adenoma and chronic atrophic gastritis with intestinal metaplasia as well as gastric cancer. Chronic persistent, uncontrolled gastric inflammations are possible basis for ensuing gastric carcinogenesis and H. pylori infection increased COX-2 expressions, which might be the one of the mechanisms leading to gastric cancer. To know the implication of long-term treatment of antiinflammatory drugs, rebamipide or nimesulide, on H. pylori-associated gastric carcinogenesis, we infected C57BL/6 mice with H. pylori, especially after MNU administration to promote carcinogenesis and the effects of the long-term administration of rebamipide or nimesulide were evaluated. C57BL/6 mice were sacrificed 50 weeks after H. pylori infection. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels and mRNA transcripts of various mouse cytokines and chemokines, and NF-${\kappa}B$ binding activities, and finally the presence of gastric adenocarcinoma were compared between H. pylori infected group (HP), and H. pylori infected group administered with long-term rebamipide containing pellet diets (HPR) or nimesulide mixed pellets (HPN). Gastric mucosal expressions of ICAM-1, HCAM, MMP, and transcriptional regulations of NF-${\kappa}B$ binding were all significantly decreased in HPR group than in HP group. Multi-probe RNase protection assay showed the significantly decreased mRNA levels of apoptosis related genes and various cytokines genes like IFN-$\gamma$, RANTES, TNF-$\alpha$, TNFR p75, IL-$1{\beta}$ in HPR group. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not changed between HP and HPR group, but significantly decreased in HPN group, suggesting the chemoprevention of H. pylori-associated gastric carcinogenesis by COX-2 inhibition. Long-term administration of antiinflammatory drugs should be considered in the treatment of H. pylori since they showed the molecular and biologic advantages with possible chemopreventive effect against H. pylori-associated gastric carcinogenesis. If the final concrete proof showing the causal relationship between H. pylori infection and gastric carcinogenesis could be obtained, that will shed new light on chemoprevention of gastric cancer, that is, that gastric/cancer could be prevented through either the eradication of H. pylori or lessening the inflammation provoked by H. pylori infection in high risk group.