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Methods in Molecular Biology (Clifton,... 2020The ethylating agent ethyl methanesulfonate (EMS) is widely used for inducing random point mutations. In Arabidopsis, treatment with EMS causes GC-to-AT transitions with...
The ethylating agent ethyl methanesulfonate (EMS) is widely used for inducing random point mutations. In Arabidopsis, treatment with EMS causes GC-to-AT transitions with great efficiency: it has been estimated that a population of 50,000 well-mutagenized plants harbors one or more transitions in almost every GC pair of the genome. These properties, combined with ease of use, make EMS a mutagen of choice for genetic screens. Here, we describe a protocol for mutagenizing Arabidopsis seed with EMS. In addition, we briefly consider the germ line sectors typically induced by this treatment, and approaches for estimating the rate of induced mutations.
Topics: Arabidopsis; Ethyl Methanesulfonate; Mutagenesis; Mutagens; Mutation; Mutation Rate; Seeds
PubMed: 31975292
DOI: 10.1007/978-1-0716-0342-0_2 -
Mutation Research Nov 2003Human population monitoring studies are frequently conducted to determine if exposure to environmental mutagenic agents can cause health problems or not. In these... (Review)
Review
Human population monitoring studies are frequently conducted to determine if exposure to environmental mutagenic agents can cause health problems or not. In these studies, a variety of biomarkers are used to identify biological events that are predictive of health consequences. An emphasis in this report is on the use of mutagen sensitivity assays to understand health risk. The assay is based on the assumption that exposure to mutagenic chemicals or mixtures of chemicals for a long time can cause cellular changes that are expressed as mutagen sensitivity. From experience in using these assays in cancer patients and in mutagen-exposed populations, it is clear that the expression of mutagen sensitivity is based on the interactions between mutagen exposure and individual susceptibility. When studies are conducted under appropriate conditions, expression of mutagen sensitivity is suggestive of increased risk for environmental disease such as cancer.
Topics: Cell Cycle; Environmental Monitoring; Humans; Micronucleus Tests; Mutagens
PubMed: 14644328
DOI: 10.1016/j.mrrev.2003.10.002 -
Mutation Research Nov 2000The Ames Salmonella/microsome mutagenicity assay (Salmonella test; Ames test) is a short-term bacterial reverse mutation assay specifically designed to detect a wide... (Review)
Review
The Ames Salmonella/microsome mutagenicity assay (Salmonella test; Ames test) is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances that can produce genetic damage that leads to gene mutations. The test employs several histidine dependent Salmonella strains each carrying different mutations in various genes in the histidine operon. These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms. When the Salmonella tester strains are grown on a minimal media agar plate containing a trace of histidine, only those bacteria that revert to histidine independence (his(+)) are able to form colonies. The number of spontaneously induced revertant colonies per plate is relatively constant. However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner. The Ames test is used world-wide as an initial screen to determine the mutagenic potential of new chemicals and drugs. The test is also used for submission of data to regulatory agencies for registration or acceptance of many chemicals, including drugs and biocides. International guidelines have been developed for use by corporations and testing laboratories to ensure uniformity of testing procedures. This review provides historical aspects of how the Ames was developed and detailed procedures for performing the test, including the design and interpretation of results.
Topics: Histidine; Microsomes; Mutagenicity Tests; Mutagens; Salmonella
PubMed: 11113466
DOI: 10.1016/s0027-5107(00)00064-6 -
Mutation Research May 1998This review surveys the chemical and biological factors that are correlated with the mutagenic activity of the aromatic and heterocyclic amines. Particular attention is... (Review)
Review
This review surveys the chemical and biological factors that are correlated with the mutagenic activity of the aromatic and heterocyclic amines. Particular attention is given to the predicted quantum chemical properties of the parent amines and their metabolites. A number of chemical properties have been found to correlate well with measured mutagenic potency, including log P, the energies of the frontier orbitals of the parent amines, and the thermodynamic stability of the nitrenium ion, possibly the ultimate DNA-binding species. These correlations are intriguing clues to the mutagenic activity of the aromatic amines; however, many factors still await final explanation, including the exact mechanisms of the metabolic enzymes, the identity(s) of the ultimate DNA-binding species, the reaction mechanism in the DNA-adduction, the role of sequence context in the covalent and non-covalent binding of the adducts, and the role of DNA repair.
Topics: Animals; Biotransformation; Humans; Mutagenesis; Mutagenicity Tests; Mutagens; Structure-Activity Relationship
PubMed: 9685706
DOI: 10.1016/s0027-5107(98)00073-6 -
Mutation Research Mar 1998Organisms combat pollutants by inducing biotransformation pathways, which can be used for biomonitoring. Several parameters--biomarkers--change in stressed organisms or... (Review)
Review
Organisms combat pollutants by inducing biotransformation pathways, which can be used for biomonitoring. Several parameters--biomarkers--change in stressed organisms or populations at different organisation levels. Molecular or cellular biomarkers are early-warning indicators of pollution. Xenobiotics are first biotransformed by phase I enzymes and then conjugated with endogenous metabolites by phase II enzymes. Many organic xenobiotics are initially biotransformed by cytochrome P4501A1; in mammals, it is induced by pollutants via Ah receptor, although in marine invertebrates, its inducibility is much more equivocal. Metallothioneins are small Cys-rich proteins which bind transition metals; they detoxicate pollutant metals and are clearly induced in metal-exposed marine invertebrates. Some pollutants are genotoxins or can be converted into them. Determination of mutagens in bivalve molluscs following extraction with solvents and assay of mutagenicity with bacterial tests is a useful biomarker for marine pollution. While some pollutants are directly mutagenic, others are only mutagenic after they are activated to mutagenic derivatives by monooxygenases or conjugative enzymes. Many of these catalysts are induced by xenobiotics; thus, increased activation of known promutagens can be used as biomarker of environmental pollution. Bioactivation of promutagens requires the simultaneous action of different pathways, thus, reproducing more closely the in vivo situation than the specific assay of individual biotransforming enzymes. Study of molluscs with different pollution levels indicates that polluted animals have higher capacity to activate 2-aminoanthracene and contain more apolar mutagens than those from reference areas.
Topics: Animals; Biomarkers; Biotransformation; Environmental Monitoring; Mollusca; Mutagens; Water Pollution, Chemical; Xenobiotics
PubMed: 9635485
DOI: 10.1016/s0027-5107(97)00262-5 -
Nature Apr 1995
Topics: Animals; Butyrates; Fishes; Japan; Mutagenicity Tests; Mutagens; Salmonella typhimurium; Sulfhydryl Compounds
PubMed: 7715699
DOI: 10.1038/374599a0 -
Mutation Research Feb 1982When rhizome juice of ginger, zingiber officinale, was added to a solution of 2(2-furyl)-3(5-nitro-2-fury)acryl amide (AF2) or N-methyl-N'-nitro-N-nitrosoguanidine...
When rhizome juice of ginger, zingiber officinale, was added to a solution of 2(2-furyl)-3(5-nitro-2-fury)acryl amide (AF2) or N-methyl-N'-nitro-N-nitrosoguanidine (NTG), mutagenesis by these chemicals was markedly increased. As a result of the component fractionation of the ginger juice, it was found that [6]-gingerol was a potent mutagen. However, the ginger juice also contained anti-mutagenic component(s) against [6]-gingerol (CAS No. 58253-27-3) (present study) and tryptophan pyrolysates (Kada et al., 1978; Morita et al., 1978). It is suggested, therefore, that the [6]-gingerol component may be mutagenically activated by the presence of AF2 and NTG.
Topics: Catechols; Condiments; Dose-Response Relationship, Drug; Drug Antagonism; Drug Synergism; Escherichia coli; Fatty Alcohols; Furylfuramide; Methylnitronitrosoguanidine; Mutagenicity Tests; Mutagens; Mutation; Plant Extracts; Plants; Species Specificity
PubMed: 7035917
DOI: 10.1016/0165-7992(82)90016-1 -
Carcinogenesis 1982The World Health Organisation (WHO) has recently recommended the use of a simple in vitro test (Nitrosation Assay Procedure, NAP) to allow the ranking of orally... (Comparative Study)
Comparative Study
The World Health Organisation (WHO) has recently recommended the use of a simple in vitro test (Nitrosation Assay Procedure, NAP) to allow the ranking of orally administered drugs. It was suggested that the ranking of drugs should be carried out on a reactivity scale, according to their ability to nitrosate in the presence of high concentrations of nitrite at low pH (3-4). The present study was undertaken to investigate the effect of adding the concentration of nitrite recommended for the NAP Test (40 mM) to normal fasting human gastric juice. The data clearly demonstrate that such treatment results in the formation of derivatives with specific mutagenic activity for the bacterium Salmonella typhimurium TA1537. This strain was recommended for use in the NAP Test. Although the NAP Test may be valid for its original purpose, in the absence of more physiologically relevant data it is invalid for use as a final arbiter in risk-benefit assessments. The possible formation of mutagenic species as a result of the nitrosation of natural gastric secretions should be considered when any risk-benefit assessment is made.
Topics: Amines; Evaluation Studies as Topic; Fasting; Gastric Juice; Humans; Hydrogen-Ion Concentration; Mutagenicity Tests; Mutagens; Nitrites; Risk; Salmonella typhimurium
PubMed: 7046984
DOI: 10.1093/carcin/3.5.597 -
Journal of Applied Toxicology : JAT Apr 1984A browning model system, consisting of diacetyl and ammonia, produced frameshift and base-pair substitution mutagens when the system was heated over 20 min and 120 min,...
A browning model system, consisting of diacetyl and ammonia, produced frameshift and base-pair substitution mutagens when the system was heated over 20 min and 120 min, respectively. The major product was 2,4,5- trimethylimidazole , which showed no mutagenicity toward Salmonella typhimurium strains TA98 and TA100 with or without metabolic activation. When furfural was reacted with nitrate under mild conditions (for 30 min to 3 h at 0-25 degrees C and pH 2-7), it did not produce mutagenic nitrofuran derivatives. However, the ethyl ether extract obtained from the reaction mixture of furfural and nitrate with hydrochloric acid exhibited strong mutagenic activities toward S. typhimurium strains TA98 and TA100 in the presence of metabolic activation. The major product of this reaction mixture, 4- nitrofurfural , exhibited no mutagenicity toward tester strains TA98 and TA100 with or without metabolic activation. Pure active mutagen(s) was (were) not, however, identified in either system.
Topics: Ammonia; Animals; Diacetyl; Food Additives; Furaldehyde; Hot Temperature; Imidazoles; In Vitro Techniques; Models, Biological; Mutagenicity Tests; Mutagens; Nitrofurans; Rats; Salmonella typhimurium
PubMed: 6376605
DOI: 10.1002/jat.2550040208 -
Cancer Letters Oct 1981Compounds mutagenic toward Salmonella typhimurium strains sensitive to frameshift mutation (1537, 1538 and TA98) were formed when fish flesh was fried at 190 degrees c....
Compounds mutagenic toward Salmonella typhimurium strains sensitive to frameshift mutation (1537, 1538 and TA98) were formed when fish flesh was fried at 190 degrees c. Four species of marine fish commonly consumed in the United States were cooked in an electric skillet and broiled beneath the elements of an electric oven. Organic extracts of the fish were tested in the Salmonella mutagenic assay using strains 1535, 1537, 1538, TA98 and TA100. Basic organic extracts of fried but not raw or broiled samples exhibited significant mutagenicity with metabolic activation. Mutagenic activity ratios ranging from 3.3 to 15.7 for the extract from 20 g of fish were observed. The mutagenicity produced during the frying of fish was dependent on time. Frying times of less than 6 min produced no mutagenic activity, while at 6 min or greater substantial mutagenicity was generated.
Topics: Animals; Cooking; Fishes; Hot Temperature; Meat; Mutagenicity Tests; Mutagens; Salmonella typhimurium; Tissue Extracts
PubMed: 7028249
DOI: 10.1016/0304-3835(81)90014-8