Hematological effects of ethyl methanesulfonate, paraquat and phenylhydrazine in Japanese quail

1. Juvenile Coturnix coturnix japonica males were injected intravenously with 2, 20 or 200 mg ethyl methanesulfonate (EMS)/kg body wt; 0.2, 2 or 20 mg paraquat (PARA)/kg body wt; or 0.6, 6 or 60 mg phenylhydrazine (PHZ)/kg body wt; and hematologic variables were measured at 0 (non-injected), 24 and 72 hr post-injection. 2. EMS, PARA and PHZ-induced hemolytic anemia began within 24 hr post-injection. 3. Recovery from anemia began within 72 hr post-injection of EMS or PARA, but PHZ injected quail continued to show a marked anemia at that time. 4. EMS and PARA induced lymphocytopenia, monocytopenia and heterophilia, while PHZ induced lymphocytosis, monocytopenia and heteropenia after injection. 5. These results suggest that the anemia induced by EMS and PARA was dissimilar from that induced by PHZ, that all chemicals affected leukopoiesis and that Japanese quail can mount a marked recovery from the hematologic affects of PARA, a widely used herbicide, in a short interval after intoxication.     

Sensitivity of Bloom's syndrome lymphocytes to ethyl methanesulfonate

Summary Ethyl methanesulfonate induced several times as many sister chromatid exchanges (SCEs) in lymphocytes from individuals affected with Bloom's syndrome as in lymphocytes from controls or heterozygotes. In cultures of cells from an individual with Bloom's syndrome who had two populations of lymphocytes circulating in his blood—low cells having normal spontaneous frequencies of SCEs and high cells having elevated frequencies—only the high cells showed the increased sensitivity to ethyl methanesulfonate.To whom offprint requests should be sent     

Survival and mutagenesis of bacteriophage T7 damaged by methyl methanesulfonate and ethyl methanesulfonate

We have examined survival and mutagenesis of bacteriophage T7 after exposure to the alkylating agents methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS). It was found that although both alkylating agents caused increased reversion of specific T7 mutations, EMS caused a higher frequency of reversion than did MMS. Exposure of the host cells to ultraviolet light so as to induce the SOS system resulted in increased survival (Weigle reactivation) of T7 phage damaged with either EMS or MMS. However, after SOS induction of the host we did not detect an accompanying increase in mutation frequency measured as either reversion of specific T7 mutants or by generation of mutations in the T7 gene that codes for phage ligase. Neither mutation frequency nor survival of alkylated phage was affected by the umuD,C mutation in the Escherichia coli host nor by the presence of plasmid pKM101. This may mean that the mode of Weigle reactivation that is detected in T7 is not mutagenic in nature.     

Dose-rate effects of ethyl methanesulfonate on survival and mutation induction in cultured Chinese hamster cells

The dose-rate effects of ethyl methanesulfonate (EMS) on the survival and induction of mutations in Chinese hamster Don cells were investigated. The most effective time of exposure to EMS for reducing the surviving fraction of cells was 4 h, shorter and longer exposure times being less effective. The threshold or minimal concentration of EMS giving a surviving fraction of 0.5 was 0.05 mg/ml. The minimal effective time of exposure to EMS for cell death was 1 h. Corrected survival curves showed that longer exposure times at lower dose rates of EMS had less cytotoxic effect than shorter exposure times at higher dose rates.After exposure of Don cells to various doses of EMS for various times, the frequencies of mutations resistant to 6-thioguanine (6TG) were measured. An exposure time of 4 h produced a lower mutation frequency than shorter or longer exposure times that resulted in the same surviving fraction of cells. An exposure time of 20 h produced the highest induced mutation frequency.This system using cultured Chinese hamster cells should be useful as a sensitive procedure for detecting the mutagenic actions of chemicals.     

Combined mutagenicity of methyl methanesulfonate and ethyl methanesulfonate in Chinese hamster V79 cells.

The combined effects of methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS) on the induction of 6-thioguanine (6TG)-resistant mutants and chromosome aberrations were examined in Chinese hamster V79 cells. Cells were simultaneously treated with EMS at a concentration of D20 and MMS at various concentrations for 3, 6 or 9 h. In other experiments cells were simultaneously treated with MMS at a concentration of D20 and EMS at various concentrations for 3, 6 or 9 h. The mathematical analysis of the combined effects of both chemicals for cell killing (cytotoxicity) and 6TG-resistant mutations indicates that synergistic interactions were observed for both cell killing and mutations induced by MMS and EMS. The frequency of chromosome aberrations induced by simultaneous treatment with MMS at a concentration of D20 and EMS at various concentrations for 3 h was additive. However, the frequency of chromosome aberrations induced by EMS at a concentration of D20 and MMS at various concentrations for 3 h was not significantly different from those induced by MMS alone.     

Quantitative assessment of the mutagenic effect of ethyl methanesulfonate inMicrococcus glutamicus

Micrococcus glutamicus ATCC 13032, a glutamic acid-excreting organism, was mutated by treating a 6–8 h old culture with 0.2m ethyl methanesulfonate (EMS) in a phosphate buffer of pH 7.6 for 150 min. The auxotrophs isolated showed varied patterns of extracellular amino acids, 38 isolates excreted lysine up to 1–2 mg/ml but most lost their excretion potency in subsequent fermentation trials although they remained auxotrophic. Most of the auxotrophs showed a requirement for amino acids.     

Sensitivity of individual Drosophila to the mutagenic action of ethyl methanesulfonate

The genetic effect of some factors is generally evaluated as an average response of all individuals, without taking into account their potential differences. The presence of individual sensitivity in separate Drosophila organisms to the mutagenic influence of ethyl methanesulfonate was shown when analysing recessive sex-linked lethal mutations in germ cells of males. Different sensitivity of separate individuals to mutagens reflects the existence of cryptic genetic variability in Drosophila strains on a large scale. It is advisable to take into account individual sensitivity of organisms to mutagenic factors, when conducting mutation research and studying genetic consequences of biosphere pollution.     

A review of tricaine methanesulfonate for anesthesia of fish

Tricaine methanesulfonate (TMS) is an anesthetic that is approved for provisional use in some jurisdictions such as the United States, Canada, and the United Kingdom (UK). Many hatcheries and research studies use TMS to immobilize fish for marking or transport and to suppress sensory systems during invasive procedures. Improper TMS use can decrease fish viability, distort physiological data, or result in mortalities. Because animals may be anesthetized by junior staff or students who may have little experience in fish anesthesia, training in the proper use of TMS may decrease variability in recovery, experimental results and increase fish survival. This document acts as a primer on the use of TMS for anesthetizing juvenile salmonids, with an emphasis on its use in surgical applications. Within, we briefly describe many aspects of TMS including the legal uses for TMS, and what is currently known about the proper storage and preparation of the anesthetic. We outline methods and precautions for administration and changes in fish behavior during progressively deeper anesthesia and discuss the physiological effects of TMS and its potential for compromising fish health. Despite the challenges of working with TMS, it is currently one of the few legal options available in the USA and in other countries until other anesthetics are approved and is an important tool for the intracoelomic implantation of electronic tags in fish.     

Synergism of mutant frequencies in the mouse lymphoma cell mutagenicity assay by binary mixtures of methyl methanesulfonate and ethyl methanesulfonate

The effect of mixed mutagen exposures on the rate and type of induced mutants was studied in the L5178Y/TK+/-----TK-/- mouse lymphoma cell mutagenicity assay. In this assay, exposure to ethyl methanesulfonate (EMS) results in more mutants that form large colonies than small colonies. Exposure to methyl methanesulfonate (MMS) results in more mutants that form small colonies than large colonies. Other reports in the literature suggest that large colony TK-/- mutants appear to result from small-scale, perhaps single-gene mutations, and that small-colony TK-/- mutants appear to be associated with chromosomal mutations. Treating cells for 4 h with simple, 2-component mixtures containing 6.45 micrograms/ml MMS and either 261, 392, 560 or 712 micrograms/ml EMS resulted in synergism of mutants at each mixture level. The frequencies of total mutants were synergized 12, 20, 35 and 72%, respectively, in mixed exposures with graded doses of EMS, above the sums of the mixture components. Small colony mutants were synergized to a greater extent than large colony mutants. The frequencies of small colony mutants in mixed exposures were increased 31, 54, 73 and 123%, respectively, while the frequencies of large colony mutants were increased -7, -6, 11 and 39%. Statistical analyses provide strong evidence of synergism (within the limits of the assay) for total and small-colony mutants at all doses of EMS tested, and for large-colony mutants above 400 micrograms/ml EMS. Similar magnitudes of synergism resulted when other constant levels of MMS (4.30 or 8.60 micrograms/ml) were mixed with the same graded doses of EMS. The degree of synergism was dependent on EMS concentration but not on MMS concentration.     

Nuclear and extranuclear mutations in yeast induced by ethyl methanesulfonate

When zero-point mutations were induced in the yeastSaccharomyces cerevisiae using ethyl methanesulfonate (EMS) no differences were found in the frequency of auxotrophic mutants formed by a short and a prolonged treatment of the agent at equal survival level. The expression of a part of the mutations induced by a prolonged EMS treatment was delayed by one or two division cycles. The total frequency of auxotrophs due to both the zero point and delayed mutations, however, is still considerably lower than the frequency of auxotrophs induced by a prolonged treatment of EMS in some bacterial species. Both the prolonged and short EMS treatment induces in yeast also extranuclear respiration-deficient (RD) mutants at a relatively high frequency; in wild strains at equal survival level the prolonged treatment produces a higher number of RD mutants than the short one. In strain which is more susceptible to the lethal EMS effect than wild strain the number of RD mutants produced by the agent is much higher than in the wild strain. The results support the assumption of the different DNA arrangement in yeast nuclei and mitochondria and indicate the possible effect of repair mechanisms during the induction of mutations causing the respiration deficiency.     

Response of different wheat tissues to increasing doses of ethyl methanesulfonate

Mutation experiments require careful selection of a mutagen with characteristics suited to the tissue source and mutagenesis objective, and an appropriate treatment regime. The objectives of the present investigation were:-to compare the ability of immature embryos to initiate calluses and calluses derived from immature embryos to survive and grow after being treated with ethyl methanesulfonate (EMS) doses of 0.2, 0.4, 0.8, 1.2, and 1.6% (v/v) and-to compare these results with those published for seed mutagenesis. To determine if the response of tissue source to EMS treatment varied with genotype, tissues from two spring wheat cultivars, Angus and Pavon 76, were used. The combined analysis of variance detected highly significant differences (p0.01) among doses. The higher the dose, the lower the tissue survival in each tissue source. No significant differences were detected between cultivars, tissue sources, in the cultivar by dose interaction, tissue source by dose interaction, tissue source by cultivar interaction, or tissue source by cultivar by dose interaction. Hence, both cultivars and tissue sources responded similarly to EMS doses. The predicted LD₂₀ are 0.35%±0.08% for the immature embryo treatment, and 0.36%±0.10% for the callus treatment. The predicted LD₅₀ are 0.82%±0.13% for the immature embryo treatment, and 0.77%±0.13% for the callus treatment. These results were very similar to published results for seed mutagenesis, hence seed mutagenesis research may be applicable to immature embryo and callus mutagenesis.Published as paper No. 9241 journal series, Nebraska Agric. Res. Div.