• 한국환경성돌연변이발암원학회지
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• 제9권1호
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• pp.33-46
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• 1989

본 연구는 알킬화제를 처리한 CHO-K1 세포에서 DNA 복제억제와 그 회복과정의 분자론적 기작을 규명할 목적으로 방사선 이중 표지에 의한 DNA 합성율의 측정, 알칼리 자당 농도구배 초원심분리법에 의한 DNA 분자량과 후복제 회복율을 측정하여 다음과 같은 결과를 얻었다. (1) 1mM methyl methanesulfonate (MMS)와 1nM N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) 이하의 낮은 농도의 처리군에서는 DNA 합성율이 급격히 감소하였으나, 2 mM MMS, 2mM MNNG이상의 농도에서는 그 감소양상이 둔화되었다, (2) DNA 합성율은 알킬화제의 처리 직후 감소하였다가 시간경과에 따라 회복되어 처리후 4시간 째에는 대조군 수준 또는 그 이상으로 회복되었다.

• 한국동물학회지
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• 제18권3호
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• pp.131-140
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• 1975

HeLa $S_3$ 細胞를 재료로 DNA 回復合成에 미치는 Methyl methanesulfonate(MMS)와 thymidine 相似體(BUdR, IUdR)의 이중효과를 농도와 시간변화에 따라 $^3 H$-thymidine 처리에 의한 自記放射法으로 조사한 결과는 다음과 같다. 1. MMS를 단독 처리한 경우 標識細胞의 빈도는 MMS의 농도 증가에 따라 증가한다. 이는 DNA 回復合成을 한 細胞의 빈도가 증가한 결과로 細胞當 Grain 數의 증가현상과 일치한다. 시간변화에 따른 DNA 回復合成은 MMS와 $^3 H$-thymidine 처리후 2$\\sim$3시간에 최대증가율을 보인다. 2. BUdR 또는 IUdR의 단독처리후 DNA 回復合成을 일으키지 않는다. 그러나 MMS와 이중 처리할 경우 標識細胞, DNA 回復合成細胞, 그리고 細胞當 Grain 數는 MMS 단독 처리한 경우보다 훨씬 증가한다. 따라서 이 두 물질은 MMS에 의한 DNA 回復合成을 효과적으로 증가시키는 感受性物質로 작용함이 판명되었다.

• 한국환경과학회지
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• 제6권1호
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• pp.45-52
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• 1997

Methyl methanesulfonate (MMS) was fed to Drosophila melnogaster in order to investigate its toxic capability at developmental and adult stages, and the hereditary effect of toxicity and the potency for induction of sex-linked lethal mutation during the slyer-matogenesis by the means of an attached-X method. In the control group, the egg to adult viability of D. melnogaster was 95.2%, while 3. 5mM and 5.0mM treated groups were 90.0% and 84.1%, respectively. In the case of their progenies (Fl), the viability was 96.9% in the control group, while 3.5mM and 5.0mM treated groups were 54.5% and 1.6%, respectively. Therefore, these differences between two generations show significant physiological toxic effects in the next generation. In the parental generation, the developmental time was calculated 11.05 days in the control group, 12.43 days In 3.5%mM treated group, and 13.23 days in 5.0mM. In the case of Fl it was estimated 10.35 days in the control group, and 11.43 days In 3.5mM treated group. Compared with the control groups In two generations, the developmental time generally delayed as the dose of MMS increased. As to the sex-ratio, there was no differences between the control and MMS treated groups. The toxic values of adult stage showed which increased the frequency of mortality with MMS concentrations. The mortality at 120hr In the control group was 1.67% and it in 0.5mM MMS treated group 3.33%. In 2.5mM MMS treated group, it was 33.3% at 72hr, and it 95% at 120hr The increase of the morality was shown from 72hr in 4.0mM treated group which was 100% at 96hr. There was the concentration-dependent induction of sex-linked lethal mutation during the spermatogenesis by means of an attached-X method, MMS had more pronounced effect in sperm and spermaid stages in D. melnogaster.

• 방사선산업학회지
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• 제10권4호
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• pp.243-248
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• 2016

Argonaute 2 (AtAGO2) is a well characterized effector protein in Arabidopsis for its functionalities associated with DNA double-strand break (DSB)-induced small RNAs (diRNAs) and for its inducible expression upon ${\gamma}$-irradiation. However, its transcriptional regulation depending on the recovery time after the irradiation and on the specific response to DSBs has been poorly understood. We analyzed the 1,313 bp promoter sequence of the AtAGO2 gene ($1.3kb_{pro}$) to characterize the transcriptional regulation of AtAGO2 at various recovery times after ${\gamma}$-irradiation. A stable transformant harboring $1.3kb_{pro}$ fused with GUS gene showed that the AtAGO2 is highly expressed in response to ${\gamma}$-irradiation, after which the expression of the gene is gradually decreased until 5 days of DNA damage recovery. We also confirm that the AtAGO2 expression patterns are similar to that of ${\gamma}$-irradiation after the treatments of radiomimetic genotoxins (bleomycin and zeocin). However, methyl methanesulfonate and mitomycin C, which are associated with the inhibition of DNA replication, do not induce the expression of the AtAGO2, suggesting that the expression of the AtAGO2 is closely related with DNA DSBs rather than DNA replication.

• 한국환경성돌연변이발암원학회지
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• 제16권1호
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• pp.30-34
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• 1996

This study was performed to examine the availability of using medaka (Oryzias latipes) in teratological test. Medaka embryos were collected within 2 hours post-fertilization and cultured in petri dishes containing buffered saline until hatching. The embryos were treated with 0.56 mg/l chlorpyrifos-methyl and 10 mM methyl methanesulfonate at 20 stages (about 35 hours post-fertilization). Eleven developmental features were selected and observed from 33 stages (about 9 days post-fertilization). Scoring system was developed and applicated for the measurement of potential teratological effects by the test compound. Chlorpyrifos-methyl did not induce teratological effect in medaka embryos. However, we found teratological test using medaka embryo reduced the cost, labors, period and space of experiment significantly compared with teratological study using rodents. Above findings strongly suggest that medaka embryo can be used as a lab animal model for teratogenicity test instead of rodents.

• 한국동물학회지
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• 제19권2호
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• pp.71-78
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• 1976

染色體의 構造的인 異常에 미치는 Methyl methanesulfonata (MMS)와 thymidine 相似體 (BUdR, IUdR)의 영향을 究明하기 위해 사람의 白血球 培養細胞에 2.0mM의 BUdR 또는 IUdR을 24時間 前 처리하고 이어 농도를 달리한 MMS $(0.0\\sim 2.0 mM)$를 1時間 처리한 뒤 24時間째 染色體標本을 작성하여 아래와 같은 결과를 얻었다. 1. MMS를 단독 처리한 對照區에서는 관찰된 染色體 異常型의 대부분이 예상외로 染色分體 異常型을 나타냈다. 2. BUdR 또는 IUdR의 단독처리도 染色體異常을 유발한다. 또한 MMS와 이중 처리한 경우에는 단독 처리보다 染色體異常型이 훨씬 증가한다. 따라서 thymidine 相似體는 MMS에 의한 染色體 異常型을 變化시켜주는 感受性物質로 作用함이 판명되었다.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.89-94
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• 2001

Recently, single cell gel electrophoresis, also known as comet assay, is widely used for the detection and measurement of DNA strand breaks in vitro and in vivo in many toxicological fields such as radiation exposure, human monitoring and toxicity evaluation. As well defined, comet assay is a sensitive, rapid and visual method for the detection of DNA strand breaks in individual cells. Briefly, a small number of damaged cells suspended in a thin agarose gel on a microscope slide were lysed, unwinded, electrophoresed, and stained with a fluorescent DNA binding dye. The electric current pulled the charged DNA from the nucleus such that relaxed and broken DNA fragments migrated further. The resulting images which were subsequently named for their appearance as comets, were measured to determine the extent of DNA damages. However, some variations could be occurred in procedures, laboratories's conditions and kind of cells used. Hence, to overcome and to harmonize these matters in comet assay, International Workshop on Genotoxicity Test Procedure (IWGTP) was held with several topics including comet assay at Washington D.C. on March, 1999. In spite of some consensus in procedures and conditions in IWGTP, there are some problems still remained to be solved. In this respect, we attempted to set the practical optimal conditions in the experimental procedures such as lysis, unwinding, electrophoresis and neutralization conditions and so on. First of all, we determined optimal lysis and unwinding time by using 150 $\mu$M methyl methanesulfonate (MMS) which is usually used concentration. And then, we determined optimal positive control concentrations of benzo(a)pyrene (BaP) and MMS in the presence and absence of S9 metabolic activation system, respectively.

• 미생물학회지
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• 제34권1_2호
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• pp.43-50
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• 1998

여러가지 환경 stress에서 유도되는 폐렴구균 열충격단백질 GroEL의 특성에 대하여 검토하였다. 비병원성인 폐렴구균(Streptococcusa pneumoniae)을 사용하여 stress 조건을 설정하고 이 설정된 조건에서 stress에 의해 유도되는 단백질을 $^{35}S$]-methionine으로 표지하여 autoradiography를 실시하였다. 열충격을 가했을 때 유도되는 단백질(65, 73, 84-kDa 등) 중 65 kDa의 단백질(hsp65)을 DEAE-Sepharose ion exchange 및 ATP-agarose affinity chromatography를 이용하여 분리 정제하였으며 hsp65에 대해 생성된 항체를 이용하여 immunoblot을 실시하였을 때 약 60 kDa의 대장균 단백질과 반응하였으며 정제된 폐렴구균 hsp65가 대장균의 anti-GroEL monoclonal 항체와 반응함으로써 폐렴구균 hsp65가 대장균GroEL과 유사한 단백질임을 확인하였다.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.474-478
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• 1999

Modulation of unscheduled DNA synthesis by dehydroepiandrosterone (DHEA) after exposure to various chemical carcinogens was investigated in the primary rat hepatocytes. Unscheduled DNA synthesis was induced by treatment of such direct acting carcinogens as methly methanesulfonate (MMS) and ethyl methanesulfonate (EMS) or procarcinogens including benzo(a)pyrene (BaP) and 7, 12-dimethylbenz(a)anthracene (DMBA). Unscheduled DNA synthesis was determined by measuring [methyl-3H]thymidine radioactivity incorporated into nuclear DNA of hepatocytes treated with carcinogens in the presence or absence of DHEA. Hydroxyurea $(5{\times}10^{-3} M)$was added to growth medium to selectively suppress normal replication. DHEA at concentrations ranging from $(1{\times}10^{-6} M)$ to$(5{\times}10^{-4} M)$ did not significantly inhibit unscheduled DNA synthesis induced by either MMS $(1{\times}10^{-4} M)$ or EMS $(1{\times}10^{-2} M)$. In contrast, DHEA-significantly inhibited unscheduled DNA synthesis induced by BaP $(6.5{\times}10^{-5} M)$ and DMBA.$(2{\times}10^{-5} M)$. DHEA-induced hepatotoxicity in rats was examined using lactate dehydrogenase (LDH) release as an indicator of cytotoxicity. DHEA exhibit no significant increase in LDH release compared with the control at 18 h. These data suggest that nontoxic concentration of DHEA does not affect the DNA excision repair process, but it probably influence the enzymatic system responsible for the metabolic activation of procarcinogens and thereby decreases the amount of the effective DNA adducts formed by the ultimate reactive carcinogenic species.

• Mycobiology
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• 제41권3호
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• pp.159-163
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• 2013

A chemical mutagenesis technique was employed for development of mutant strains of Sparassis crispa targeting the shortened cultivation time and the high ${\beta}$-glucan content. The homogenized mycelial fragments of S. crispa IUM4010 strain were treated with 0.2 vol% methyl methanesulfonate, an alkylating agent, yielding 199 mutant strains. Subsequent screening in terms of growth and ${\beta}$-glucan content yielded two mutant strains, B4 and S7. Both mutants exhibited a significant increase in ${\beta}$-glucan productivity by producing 0.254 and 0.236 mg soluble ${\beta}$-glucan/mg dry cell weight for the B4 and S7 strains, respectively, whereas the wild type strain produced 0.102 mg soluble ${\beta}$-glucan/mg dry cell weight. The results demonstrate the usefulness of chemical mutagenesis for generation of mutant mushroom strains.