| Co-Investigator(Kenkyū-buntansha) |
MIYATA Naoyuki University of Shizuoka, Institute for Environmental Sciences, Research Associate, 環境科学研究所, 助手 (20285191)
SIMOI Kayoko University of Shizuoka, School of Food and Nutritional Sciences, Research Associate, 食品栄養科学部, 助手 (10162728)
KINAE Naohide University of Shizuoka, School of Food and Nutritional Sciences, Professor, 食品栄養科学部, 教授 (00046286)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
This research aimed at the applicability of environmental microorganisms to comet assay and its availability for evaluation of aquatic toxicity induced by environmental contaminants. The obtained results can be summarized as follows ;
Euglena gracilis, Chlamydomonas pulsatilla, Saccharomyces cerevisiae, Monas guttula and Tetraphymena pyriformis were targetted. From the results of cell lysis operation, 0.01% SDS solution was applicable to E. gracilis, 0.05% SDS solution was to C. pulsatilla and 1% Triton X-100 solution was to T. pyriformis, respectively. Changing with various times of cell lysis, unwinding and electrophoresis, applicabilities of those microorganisms to comet assay were investigated. Consequently, E. gracilis was found to be most suitable and its operational modes was determined that cell lysis time was 5 min. and each time for unwinding and electrophoresis was 20 min., respectively.
Evaluations of DNA damage and repair to hazardous chemical substances were carried out with comet assay using E. gracilis. Within the range of each molarity at which the survival of E. gracilis could be confirmed by dye exclusion test, DNA damages were detectable for MNNG and BAP, but were not for MMC and AMD. Using MNNG-treatment and γ-irradiation, the results of DNA repair evaluation were shown that DNA could be repaired within 1 hr. Comparing with the results by lymphocyte of human, more than 10-fold and 2-fold sensitivities in MNNG- and BAP-treatments, respectively, were shown in comet assay using E. gracilis.
Judging from the above-mentioned results, it was concluded that comet assay using E. gracilis, developed by this research, was applicable to evaluate aquatic toxicity induced by environmental contaminants.
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