• Title, Summary, Keyword: mutagenesis

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ANTIMUTAGENIC STUDY OF SELENIUM COMPOUNDS

  • Bronzetti, Giorgio;Leonardo Caltavuturo, Marco Cini;Croce, Clara Della
    • Proceedings of the Korean Society of Toxicology Conference
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    • pp.10-10
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    • 2001
  • Selenium is an essential nutritional element for several animal species and human. It has been also seen, that low levels of selenium in the diet can cause many diseases. This metalloid was defined like a "double face" element because it possesses antioxidant, antimutagen, anticarcinogen but also mutagenic and carcinogenic effects. The most important metabolic role of selenium in the animal species is its presence in the Glutathione Peroxidase(GSH-Px). (omitted)

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Inhibitory Effects of Synurus deltoides Extracts on the Mutagenesis Induced by Various Mutagens (각종 변이원들에 의해 유도된 돌연변이원성에 대한 수리취 추출물의 억제작용)

  • 함승시;한홍식;최근표;오덕환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.3
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    • pp.528-533
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    • 1997
  • This study was undertaken to determine the antimutagenic effects of Synurus deltoides extracts on the mutagenesis induced by 3-amino-1, 4-dimethyl-5-H-pyrido[4, 3-blindol(Trp-P-1), 2-amitnofluorene (2-AF) and 4-nitroquinolin-1-oxide(4NQO) using Ames test. Raw juice, heated juice, and ethanol extract from Synurus deltoides itself did not induce mutagenesis. The raw juice, heated juice and ethanol extract of 50${mu}ell$/plate showed approximately 90%, 37% and 28% inhibitory effect on the mutagenesis induced by Trp-P-1 against TA98 strain, while 80%, 60% and 58% inhibition was observed on the mutagenesis induced by 2-AF at the concentration of 200${mu}ell$/plate, respectively. TA100 strain was more sensitive than TA98 strain by raw juice, heated juice and ethanol extract on the mutagenesis induced by Trp-P-1 and 2-AF. Meanwhile, the raw juice, heated juice, and ethanol extract showed very limited inhibitory effects on the mutagenesis induced by 4-NQO against TA98 and TA100 strain. These results indicate that raw juice had the strongest inhibitory effect on the Trp-P-1 or 2-AF induced mutagenesis, but all of the extracts had a little antimutagenc effects on the 4-NQO induced mutagenesis.

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Next-generation gene targeting in the mouse for functional genomics

  • Gondo, Yoichi;Fukumura, Ryutaro;Murata, Takuya;Makino, Shigeru
    • BMB Reports
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    • v.42 no.6
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    • pp.315-323
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    • 2009
  • In order to elucidate ultimate biological function of the genome, the model animal system carrying mutations is indispensable. Recently, large-scale mutagenesis projects have been launched in various species. Especially, the mouse is considered to be an ideal model to human because it is a mammalian species accompanied with well-established genetic as well as embryonic technologies. In 1990', large-scale mouse mutagenesis projects firstly initiated with a potent chemical mutagen, N-ethyl-N-nitrosourea (ENU) by the phenotype-driven approach or forward genetics. The knockout mouse mutagenesis projects with trapping/conditional mutagenesis have then followed as Phase II since 2006 by the gene-driven approach or reverse genetics. Recently, the next-generation gene targeting system has also become available to the research community, which allows us to establish and analyze mutant mice carrying an allelic series of base substitutions in target genes as another reverse genetics. Overall trends in the large-scale mouse mutagenesis will be reviewed in this article particularly focusing on the new advancement of the next-generation gene targeting system. The drastic expansion of the mutant mouse resources altogether will enhance the systematic understanding of the life. The construction of the mutant mouse resources developed by the forward and reverse genetic mutagenesis is just the beginning of the annotation of mammalian genome. They provide basic infrastructure to understand the molecular mechanism of the gene and genome and will contribute to not only basic researches but also applied sciences such as human disease modelling, genomic medicine and personalized medicine.

An Effects of Enzymatic Browning Reaction Products of Potato on the Antimutagenesis

  • Ham, Seung-Shi;Park, Kun-Pyo;Park, Book-Kil;Deoghwan Oh
    • Preventive Nutrition and Food Science
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    • v.2 no.3
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    • pp.232-235
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    • 1997
  • This study was investigated to determine antimutagenic effects of enzymatic browning reaction products (PEBRPs) obtained by reaction of polyphenol compouns with oxidase extracted from potato. Catechol (Ca) PEBRPs showed the strongeest inhibitor effects with 90% inhibition on benzo-($\alpha$)-pyrene(B($\alpha$)P) induced mutagenesis in Salmonella typhimurium TA98, but he least with40% inhibition on the 2-aminofluorene (2-AF) induced mutagenesis in TA98. The strong antimutagenic activities with 80% inhibition were observed in the presence of 100$\mu\textrm{g}$/plate of hydroquinone(HQ)-PEBRP on the B($\alpha$)P or 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole(Trp-P-1) induced mutagenesis in TA98, whereas HQ-PEBRP showed the least antimutagenic effect on 2-AF-induced mutagenesis. The addition of 100$\mu\textrm{g}$ hydroxyhydroquinone(HHQ)-PEBRP to the plate led to approximately 82% inhibitory effects on 2-AF or Trp-P-1 induced mutagenesis in TA98, whereas the least antimutagenicity was obsrved in the4-nitroquinoline-1-oxide(4-NQO) induced mutagenesis in the presence of 100$\mu\textrm{g}$/plate of HHQ-PEBRP. More than 80% inhibiton were observed in the presence of 200$\mu\textrm{g}$/plate of Pyrogalol(Py)-PEBRP on the B($\alpha$)P or Trp-P-1 induced mutagenesis in TA98, but the least with 38% inhibition on 4-NQO induced mutagenesis in TA98. The results indicate that enzymatic browing reaction products of potato have a strong modulatory effect on mutagen induced mutagenesis in TA98.

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Isolation of Trp, Thr Overproducing Strain of Saccharomyces cerevisiae (Trp, Thr Analogue 복합 저항성 Saccharomyces cerevisiae 균주 개발)

  • 염형준;이승현;김선혜;선남규;안길환;이봉덕;원미선;송경빈
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.1017-1021
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    • 2004
  • To isolate a mutant which overproduces threonine and tryptophan, mutants of Saccharomyces cerevisiae were screened after UV and EMS mutagenesis. Hydroxynorvaline, a Thr analogue was used for selection of a Thr-overproducing mutant after UV mutagenesis. Among 31 mutants, TC 5-1 was selected as the strain candidate, based on amino acid analysis. TC 5-1 was then treated by EMS mutagenesis for Trp overproduction. Eight mutants were selected using fluorotryptophan for Thr and Trp overproducing strains. Amino acid analysis results showed that TC 6-1 was the best strain since it had the highest amount of Thr and Trp among mutants.

Transgenic Mutagenesis Assay to Elucidaate the Mechanism of Mutation at Gene Level (유전자수준에서 돌연변이 유발기전을 밝히는 Transgenic Mutagenesis Assay)

  • Ryu, Jae-Chun;Youn, Ji-Youn;Cho, Kyung-Hae;Chang, Il-Moo
    • Environmental Mutagens and Carcinogens
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    • v.18 no.1
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    • pp.15-21
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    • 1998
  • Transgenic animal and cell line models which are recently developed and used in toxicology fields combined with molecular biological technique, are powerful tools to study the mechanism of mutation in vivo and in vitro, respectively. Transgenic models, which have exogenous DNA incorporated into their genome, carry recoverable shuttle vector containing reporter genes to assess endogenous effects or alteration in specific genes related to disease processes. The lac I and lac Z gnee most widely used as a mutational target in transgenic systems. The assay is performed by treatment with putative mutagenic agents, isolation of genomic DNA from cells or tissues, exposure the isolated DNA to in vitro packaging extract, plating and sequencing. The results from these processes provide not only mutant frequency as quantitative evaluation but also mutational spectrum as qualitative evaluation of various agents. Therefore we introduce and review the principle, detailed procedure and application of transgenic mutagenesis assay system in toxicology fields especially in mutagenesis and carcinogenesis.

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Studies on N-Ethyl-N-nitrosourea Mutagenesis in BALB/c Mice

  • Cho, Kyu-Hyuk;Cho, Jae-Woo;Song, Chang-Woo
    • Toxicological Research
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    • v.24 no.1
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    • pp.59-68
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    • 2008
  • N-ethyl-N-nitrosoures (ENU) is effective in inducing hypermorphic mutation as well as hypomorphic and antimorphic mutations. Therefore, this mutagen is used to the production of mutant in the mice. In order to perform an effective ENU mutagenesis using BALB/cAnN mice, determination of optimal dosage and dosage regimen of ENU is necessary. And this study tried to develop a suitable screening method and searched for novel and various mutants as model animals in phenotypedriven ENU mutagenesis. We have carried out dosage regimen for mutagenizing dose of 200 mg/kg ENU in the BALB/c mice. Total screened mice were 30,133. As the results of Esaki and Cho's Phenotype Screening, we got 2,516 phenotypic and behavior abnormalities in $G_1,\;G_2\;and\;G_3$ mice. One hundred thirty five $G_1$ phenodeviants were tested for inheritance and 16 dominant mutants were discovered. Forty two recessive mutants were also found in tested 201 micropedigrees. Early-onset mutant mice included the dysmorphology of face, eye, tail, limb, skin, and foot and abnormal behavior like circling, swimming, head tossing, stiff-walking, high cholesterol level, and tremor etc. In this study we could effectively screen $G_3$ recessive mutants. The frequent and concise early-onset screening before weaning will be available for ENU mutagenesis.

Isolation and Characterization of plasmid pKM 101 mutants Deficient in Their Ability to Enhance Mutagenesis (돌연변이율을 증가시키는 기능이 결여된 플라스미드 pKM101의 분리 및 그 특성에 관한 연구)

  • 박찬규;하지홍;이세영
    • Korean Journal of Microbiology
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    • v.18 no.1
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    • pp.29-34
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    • 1980
  • As preliminaries for the study of Plasmid pKM101 functions nad their interaction with the host DNA repair genes, seven mutants of pKM101, visualized on tetrazolium-galactose plates, deficient in their abitity to enhance mutagenesis were isolated and paritally characterizee. They all have altered functions not only for mutagenesis against MMS and 4-NQO but for the spontaneous reversion of host cell.

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The Production of mutant protein by a transcription-based mechanism and in vivo technique for determining transcriptional mutagenesis

  • You, Ho-Jin
    • Proceedings of the PSK Conference
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    • pp.48-55
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    • 2001
  • When an elongating RNA polymerase encounters DNA damage on the template strand of a transcribed gene it can either be arrested by or be transcribed through the lesion. Lesions that arrest RNA polymerases are thought to be subject to transcription-coupled repair, whereas that damage that is bypassed can cause miscoding, resulting in mutations in the transcript (transcriptional mutagenesis). We have developed a technique using a plasmid-based luciferase reporter assay to determine the extent to which a particular type of DNA base modification is capable of causing transcriptional mutagenesis in vivo. The system uses Escherichia coli strains with different DNA repair backgrounds and is designed to detect phenotypic changes caused by transcriptional mutageneis under nongrowth conditions. In addition, this method is capable of indicating the extent to which a particular DNA repair enzyme (or pathway) suppresses the occurrence of transcriptional mutagenesis. Thus, this technique provides a tool with which the effects of various genes on non-replication-dependent pathways resulting in the generation of mutant proteins can be gauged.

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