• 환경생물
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• 제41권4호
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• pp.637-656
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• 2023

강 하구는 높은 생산성을 나타내는 생물다양성이 가장 높은 대표 수생태계이다. 환경 DNA (eDNA)를 이용한 수생태계 모니터링은 현장의 환경 시료를 확보하여 시료 내 존재하는 생물로부터 유래된 DNA를 추출하는 방법으로서 기존의 어구를 이용한 현장조사 모니터링에 비해 효율적이고 민감도가 높아 보완적인 방법으로 이용되고 있다. 본 연구는 낙동강 수계 하구 생태계를 대표하는 내륙 습지 하천인 태화강과 창원천을 대상으로 환경특성, 어류 군집구조와 종 다양성을 파악하였다. 태화강에서는 양측회유성, 소하성 및 강하성 어류인 은어, 황어 및 뱀장어의 서식이 대부분의 조사 시기 동안 확인되어 연안에서부터 중류 및 지류까지 비교적 원활한 서식처 종적 연결성을 나타내는 생태계임을 알 수 있었다. 또한, 창원천의 경우 특히 바다와 가까운 내륙 습지 하천으로 많은 다양한 해산어류 및 망둑어류의 서식이 확인되었으나, 회유성 어종인 은어는 환경 DNA에서만 검출되었고 현장조사에서는 관찰되지 않았다. 어구조사를 통한 종 다양성 평가 결과 태화강이 창원천에 비해 낮은 우점도지수, 높은 풍부도, 균등도, 다양도지수 수치를 나타내어 상대적으로 양호한 어류 군집 구조 상태를 나타냈다. 어구를 이용한 현장조사와 환경 DNA 메타바코딩 기법을 이용하여 태화강과 창원천 하구 생태계 어류 군집 구조 및 종 다양성을 비교 분석하였다. 어구를 이용한 3회 현장조사 결과 9~19종이 확인되었고 환경 DNA 1회 분석 결과 11~18종으로 환경 DNA 분석이 현장조사 결과와 유사한 수준의 종 수를 확인할 수 있었다. 어구를 이용한 5월 현장조사 결과는 6~11종이 확인된 점을 고려하면 환경 DNA가 종 탐지에서 민감도가 더 높음을 알 수 있었다. 환경 DNA를 이용한 수생태계 모니터링을 위한 어류 종 탐지의 잠재적인 효용성을 확인할 수 있었으나 우리나라 고유종 및 유전적으로 가까운 근연종들의 경우 명확한 종 동정에 어려움이 있었으며, 현장조사 시 관찰되었으나 환경 DNA에서 검출되지 않은 경우(위음성; false negative)와 현장조사 시 관찰되지 않은 종이 환경 DNA에서 검출(위양성; false positive)되는 자료의 한계점도 존재하였다. 향후 국내 고유종의 local DB 확보, 환경 DNA 조사 표준화 방법 구축, 국내 담수어류 대상 분자마커 개발 등이 확립된다면 수생태계 모니터링에 아주 효율적이며 실용적인 조사 방법으로 적용될 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.624-627
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• 2003

Benzo[a]pyrene (B[a]P) is an environmental pollutant that has been implicated in carcinogenesis. Saccharomyces cerevisiae was treated with B[a]P, and the responses of its cytochrome P450 (CYP) enzyme and DNA-damage checkpoint genes were examined through gene expression profiles using a reverse transcription polymerase chain reaction (RT-PCR). The DNA-damage checkpoint genes tested were the chk1 and pds1 genes, involved in a metaphase arrest, the swi6 gene targeted by G1 arrest, the pol2 gene related to S phase arrest, and the cln2 gene encoding a cyclin protein, all of which are based on rad9 and rad24. Among these genes, no noticeable effect was found when the cells were exposed to various concentrations of B[a]P. However, the transcriptional activity of CYP51 was significantly different when the cells were exposed to B[a]P. Accordingly, the present results indicate that cytochrome P450 plays a more significant role than DNA-damage checkpoint genes in the response of S. cerevisiae to B[a]P.

• 환경생물
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• 제40권2호
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• pp.199-205
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• 2022

Two tree frogs, Dryophytes suweonensis and Dryophytes japonicus, inhabiting Korea, are morphologically similar and share the same habitats. Therefore, they are identified mainly through their calls, especially for males. Dryophytes suweonensis is registered as an endangered (IUCN: EN grade) and protected species in South Korea. Thus, it is necessary to develop a method to rapidly identify and discriminate the two species and establish efficient protection and restoration plans. We identified significant genetic variation between them by sequencing a maternally-inherited mitochondrial 12S ribosomal DNA region. Based on the sequence data, we designed a pair of primers containing 7bp differences for high resolution melting(HRM) analysis to rapidly and accurately characterize their genotypes. The HRM analysis using genomic DNA showed that the melting peak for D. suweonensis was 76.4±0.06℃, whereas that of D. japonicus was 75.0±0.05℃. The differential melt curve plot further showed a distinct difference between them. We also carried out a pilot test for the application of HRM analysis based on immersing D. suweonensis in distilled water for 30 min to generate artificial environmental DNA(eDNA). The results showed 1.10-1.31℃ differences in the melting peaks between the two tree frog samples. Therefore, this HRM analysis is rapid and accurate in identifying two tree frogs not only using their genomic DNA but also using highly non-invasive eDNA.

• 한국환경보건학회지
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• 제43권6호
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• pp.467-477
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• 2017

Objectives: Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects such as cancer and neurological diseases. We investigated whether protective measures could significantly reduce the levels of biomarkers for oxidative stress and DNA damage in agricultural workers. Methods: In the present study, the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), biomarkers related to oxidative stress and DNA damage, respectively, were analyzed in urine samples collected from agricultural workers in two provinces of Korea (n=60). The influence of wearing personal protective equipment (PPE) and performing protective behaviors on the levels of these two biomarkers was also evaluated. Results: The median urinary levels of MDA and 8-OHdG were 10.45 nmol/mg creatinine and 14.42 ng/mg creatinine in subjects living in region A, while they were 6.25 nmol/mg creatinine and 24.77 ng/mg creatinine in subjects living in region B, respectively. The levels of MDA and 8-OHdG were higher in male farmers. Farmers wearing greater numbers of PPE and performing more protective behaviors had significantly lower levels of MDA. Greater numbers of protective behaviors was significantly associated with lower levels of 8-OHdG. Conclusion: The results of the present study indicate that pesticide exposure could induce oxidative stress and DNA damage in agricultural workers, and that protective measures are important for mitigating pesticide exposure.

• Toxicological Research
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• 제2권1호
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• pp.1-7
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• 1986

Procarcinogen induced DNA single-strand breaks and unschduled DNA synthesis were measured in primary rat hepatocytes culture. For DNA single-strand breaks assay, rat liver DNA was prelabeled by injection 3H-thymidine during the peak of DNA synthesis following partial hepatectomy. Hepatocytes were isolated from the rat 2 weeks after surgery by a collagenase perfusion techinique and maintained as monolayers in serum free medium on collagen-coated culture dishes. DNA sigle-strand breaks were measured by the alkaline elution techinique.

• Toxicological Research
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• 제17권4호
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• pp.249-253
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• 2001

Fumonisin B1, a mycotoxin, is thought to induce esophageal cancer in humans and apoptosis in animal cells by inhibiting ceramide synthase. Dumonisin Bl may also generate reactive oxygen species directly or indirectly, leading to DNA damage and lipid peroxidation. In this study, a DNA fragmentation assay, dichlorofluorescein (DCF) analysis, and single cell gel electrophoresis (SCGE) were used to investigate the involvement of cellular free radicals, specifically hydrogen peroxide, in the DNA damaging activity of fumonisin B1. From an in vitro DNA fragmentation assay, E. coli DNA, damage by fumonisin Bl was increased by the addition of superxide dismutase (SOD) and decreased by catalase. SCGE and DCF analysis in vivo showed that the nuclear DNA damage and intracellular free radicals in cultured rat hepatocytes treated with fumonisin B1 were increased with the concentration of fumonisin Bl . DNA damage and free radical generation were inhibited by the addition of catalase. Fumonisin Bl , in the presence of SOD, produces hydrogen peroxide causing oxidative DNA damage and protein malfunction, leading to genotoxicity and cytotoxicity of the toxin.

• 생명과학회지
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• 제13권1호
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• pp.99-104
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• 2003

Aromatic compounds are of major concern among environmental pollutants due to their toxicity and persistence. To monitor aromatic compounds in a real time with a better sensitivity, a new method of SPR (surface plasmon resonance) based on DNA chip (Biacore 3000) was developed here. It is thought that CapR regulatory protein as a complex with phenol, could bind to their corresponding promoter, Po. Biotinylated DNA oligomers for the promoter was synthesized by PCR and coupled onto streptoavidin-linked CM5-chip. CapR regulatory proteins were purified after cloning their genes in pET21a (+) vector and expressing proteins. The interaction was assessed by the system where the regulatory proteins flowed with or without phenol through the cells of DNA chip. CapR regulatory protein even in the presence of phenol had no response to its promoter, Po, suggesting that other factor(s) might be required for the activation of Po promoter. The present work reveals a promising possibility of the SPR-based DNA chip in monitoring specific environmental pollutants in a real time.

• 한국환경보건학회지
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• 제27권1호
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• pp.124-130
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• 2001

Ginkgo biliba has been used for bronchitis and asthma in oriental countries and its leaf extract(GBE) contains 24% ginkgoflavone glycoside and 6% terpenoid. Flavonoids and terpenoids are known to have various antioxidant effects such as scavenging of free radicals and chelation of transtional metals. Antioxidant effect of GBE against 1,2,4-benzenetriol(BT), one of toxic metabolites of benzene, was demonstrated throughbsister chromatid exchange(SCE) analysis, single cell gel electrophoresis(SCGE) analysis, DNA cleavage assay and lipid peroxidation production analysis. The means of SCE frequencies at 10, 25 and 50$\mu$M concentration of BT were 7.72, 8.02, 9.22 respectively. In addition of GBE with concentration of 50, 200 and 500$\mu\textrm{g}$/$m\ell$, SCE frequencies were decreased significantly.(p<0.05) According to SCGE analysis, BT induced DNA damage in a dose-dependent manner at concentration of 10 and 50 $\mu$m and the DNA damage induced by BT was significantly protected by GBE(p<0.001). No genotoxicity was observed by GBE treatment alone on DNA cleavage. The effect of BT on lipid peroxidation product, Malondiadehyde(MDA), was increased with concentration of BT(10 and 50 $\mu$M) and reduction in MDA was noted when GBE was added. From above results it is suggested that GBE could protect the cell and DNA from pro-oxidant effect by reactive oxigen species induced by BT.

• 한국환경성돌연변이발암원학회지
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• 제21권1호
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• pp.34-43
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• 2001

Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate ester in polyvinyl chloride formulations including food packing and storage of human blood. DEHP is a well known as non-genotoxic carcinogen and endocrine disrupting chemical (EDC). DEHP have shown all negative results in ICH-guildeline recommended standard genotoxicity test battery. In this study, to assess the clastogenic and DNA damaging effect in human-derived tissue specific cells, DEHP was treated in human derived MCE-7 cells, HepG2 cells, LNCap cells, BeWo cells, MCE-10A cells, and female peripheral blood cells using micronucleus assay and in human breast carcinoma MCF-7 cells up to $1.28$\times$10^{-2}$ M using Comet assay. The in vitro micronucleus assay is a mutagenicity test system for the detection of chemicals which induce the formation of small membrane bound DNA fragment i.e. micronuclei in the cytoplasm of interphase cells, originated from clastogenic and/or aneugenic mechanism. The single cell gel electrophoresis assay (Comet assay) is used to detect DNA strand-breaks and alkaline labile site. In our results, DEHP increased significantly and/or dose-depentently and time-dependently micronucleus frequency at the 6 and 24 hr without metabolic activation system only in MCE-7 cells. DEHP treated with 2 hrs in MCF-7 cells using Comet assay induced DNA damage dose-depentantly.

• 한국환경과학회지
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• 제22권1호
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• pp.37-45
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• 2013

The monthly variations of blood characteristics and RNA/DNA of black sea bream, Acanthopagrus schlegeli, habituated in Geojae costal area were analysed to determine health condition of natural stocks in terms of gonad maturation and spawning season from March 2010 to February 2011. Spawning season determinated by gonadosomatic index is from June to August. RNA/DNA ratio of black sea bream muscle was strongly correlated with spawning season. During the gonad maturation RNA/DNA ratio in dorsal muscle tissue was decreased contrast to rapid increase during spawning season. Blood composition factors increased in terms of gonad maturation are aspartate aminotransferase, cholesterol, triglyceride, total protein, glucose, globulin, alkaline phosphatase and inorganic phosphate. Other blood factors increased during spawning season are alanine aminotransferase, blood urea nitrogen, uric acid and lactate dehydrogenase.