• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.212-217
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• 2010

Soil pollution by heavy metals has become a significant environmental concern due to a variety of human activities. Specially toxicity caused by excessive mercury exposure is now being recognized as a widespread environmental problem and is continuing to attract a great deal of public concerns. The earthworms are very important animals that aerate the soil with their burrowing action and enrich the soil by decomposing organic matters. Especially the earthworm Eisenia fetida is routinely used in ecotoxicological studies. The levels of DNA damage in earthworms treated with HgCl2 and ionizing radiation were investigated in this study. Genotoxic effects were evaluated in the earthworm's coelomocytes using the comet assay (Single Cell Gel Electrophoresis; SCGE). The results showed that the mercury chloride and radiation were responsible for the genotoxic effects on earthworms. The level of DNA damage significantly increased after the treatment of mercury chloride combined with ionizing radiation. The combined treatment of $HgCl_2$ and ionizing radiation had a greater genotoxicity. This study is amenable to further study such as enzyme activation assay.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.46-52
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• 2006

The mercury is among the most highly bioconcentrated toxic trace metals. Many national and international agencies and organisations have targeted mercury for the possible emission control. The mercury toxicity depends on its chemical form, among which alkylmercury compounds are the most toxic. A human cervix uterus cancer cell line HeLa cells was employed to investigate the effect of the toxic heavy metal mercury (Hg) and ionizing radiation. In the in vitro comet assays for the genotoxicity in the HeLa cells, the group of Hg treatment after irradiation showed higher DNA breakage than the other groups. The tail extent moment and olive tail moment of the control group were $4.88{\pm}1.00\;and\;3.50{\pm}0.52$ while the values of the only Hg treatment group were $26.90{\pm}2.67\;and\;13.16{\pm}1.82$, respectively. The tail extent moment and olive tail moment of the only 0.001, 0.005, 0.01 Hg group were $12.24{\pm}1.82,\;8.20{\pm}2.15,\;20.30{\pm}1.30,\;12.26{\pm}0.52,\;40.65{\pm}2.94\;and \;20.38{\pm}1.49$, respectively. In the case of Hg treatment after irradiation, the tail extent moment and olive tail moment of the 0.001, 0.005, 0.01 Hg group were $56.50{\pm}3.93,\;32.69{\pm}2.48,\;62.03{\pm}5.14,\;31.56{\pm}1.97,\;72.73{\pm}3.70\;and \;39.44{\pm}3.23$, respectively. The results showed that Hg induced DNA single-strand breaks or alkali labile sites as assessed by the Comet assay. It is in good agreement with the reported results. The mercury inhibits the repair of DNA. The bacterial formamidopyrimidine-DNA glycosylase (Epg protein) recognizes and removes some oxidative DNA base modifications. Enzyme inactivation by Hg (II) may therefore be due either to interactions with rysteine residues outside the metal binding domain or to very high-affinity binding of Hg (II) which readily removes Zn (II) from the zinc finger.

• Journal of Environmental Science International
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• v.19 no.12
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• pp.1335-1341
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• 2010

Voltammetric diagnostics of pesticide thiram was studied in plant leafs in vivo fluid with DNA immobilized on a carbon nanotube electrode (DCE). Sensor properties of carbon nanotube (CE) and DNA immobilized nanotube were compared. DCE was more effective than CE in target detecting. The parameters such as pH strength, stripping accumulation, amplitude, and increment potential were examined to find the optimum condition for detection of pesticide thiram in a sesame leaf. The optimized conditions were as follows 550 Hz frequency, 0.15 V amplitude, 0.005 V increment potential, -1.2 V initial potential, 4.78 pH, 500 sec accumulation time. Under optimum condition, the detection limit of thiram was attained at 0.01ng/L.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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• pp.135-141
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• 2001

Endocrine disruptors have been implicated in carcinogenesis in animal studies, but carcinogenetic effects on human remain controversial. In order to examine the genotoxicity of two common endocrine disruptors, Bisphenol A and Diethylstilbestrol, cytogenetic endpoints including chromosome aberration (CA), sister chromatid exchange (SCE), micronuclei (MN) analyses and DNA damage by single cell gel electrophoresis (SCGE) were assessed. The effects of Bisphenol A and Diethylstilbestrol on the frequencies of CA and MN were increased in a dose-dependent manner and that of Bispheol A was more significant by Kendall'$\tau$test. Bisphenol A and Diethylstilbestrol also increased the frequency of SCE. Bisphenol A and Diethylstilbestrol induced DNA damage in a dose-dependent manner and the DNA damage induced by Diethylstilbestrol in human blood lymphocytes was more significant.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.199-200
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• 2002

• Environmental Mutagens and Carcinogens
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• v.10 no.1
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• pp.1-10
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• 1990

The regulation of DNA repair genes expression was investigated using fused genes, in which the promoter of repair genes was hybridized with the lacZ structural gene. The activities of beta-galactosidase expressed from the fused gense were highly increased when the host cells were exposed to methylating agents, such as methyl methansulfonate (MMS), N-methyl-N'-nitro-nitrosoguanidine (MNNG) and methyl nitrosourea (MNU). On the other hand, the enzyme activities from the fused genes were not induced when the cells were treated with ethylating or nonalkylating agents, such as ethyl methansulfonate (EMS), 4-nitroquinoline-1-oxide (4NQO), Bleomycin, and Benzo(a)pyrene (BP).

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.121-124
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• 2003

The goals of this study is to elucidate life cycle and to detect genetic differences within a single species of Heterosigma akashiwo. To elucidate life cycle of H. akashiwo, have to study of benthic stage and vegetative cell. So we studied identification of H. akashiwo cyst. The relative contents of DNA in nuclei were determined in Heterosigma akashiwo. Different stages of the life history were obtained from culture and natural sediments, and examined by microfluorometry after staining with the DNA-specific fluorochrome 4'-6-dianudubi-2-phenylindole(DAPI). Large cells mainly in exponensial stage, while small cell, pre-encystment cells(\ulcorner\ulcorner), showed in the end of the late growth stage. Type of DNA content showed the different with growth stage. Usually the small cell has the high level of IOD.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.368-380
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• 2022

Biomonitoring of an invasive alien crayfish species, Procambarus clarkii (Girard, 1852), was performed from February to October 2021, along with environmental DNA analysis, at five locations including Wanju-gun, Hampyeong-gun, Naju-si, Gurye-gun, and Cheongju-si. For the investigation, an umbrella-shaped trap for adults and a hand net for young crayfish were used, and 8 to 10L of freshwater was collected for eDNA analysis. The current status and past distributional records of crayfish in Korea were analyzed along with benthic macroinvertebrates at each survey site. As a result of the investigation, a total of 122 individuals were identified, and Hampyeong-gun recorded the largest number of populations with 59 individuals (48.36%) and the highest environmental DNA (eDNA). The frequency of appearance of P. clarkii was highest in May. The ratio of females to males was 21:5, and the body size was 72.2±21.1mm for female, 80.5±15.6mm for male, and 25.3±9.8mm for young crayfish. P. clarkii introduced into Korea is mainly spreading in the southwest region and it has not been observed in Seoul where there had been a record of appearance in the past. No external symbiosis (Branchiobdellida) of P. clarkii has been identified, and P. clarkii that has appeared in Korea was presumed to be imported from Japan. There are more than eight kinds of exotic crayfish distributed in Korea, and among them, the marbled crayfish (P. virginalis) was identified as a harmful species to the ecosystem of Korea by the Ministry of Environment in 2021. The identified species of benthic macroinvertebrates inhabiting the survey area where P. clarkii has appeared were 69 belonging to 39 families, 15 orders, five classes, and three phyla. Among them, Odonata were the most abundant (16 spp.; 24.62%), followed by Coleoptera (11 spp.; 16.92%) and Hemiptera (11 spp.; 16.92%). In the survey area, one Korean endemic species (Rhoenanthus coreanus), one species (Helophorus auriculatus) classified as Near Threatened (NT) on the Korean Red List, and six species of Crustaceans appeared. In the functional feeding group, the predators appeared predominantly while in habitat oriented group, the climbers appeared to be abundant. It was confirmed that P. clarkii in the survey area prefers an area rich in aquatic vegetation with waterside vegetation, and has high resistance to turbid water quality. The omnivore invader P. clarkii is expected to maintain a competitive relationship with carnivorous benthic macroinvertebrates that are predominant in the same species, and is expected to continue to generate ecosystem disturbance along the food chains.

• Annual Conference of KIPS
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• 2006.11a
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• pp.609-612
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• 2006

본 연구는 진단용 DNA 칩의 자동판독 시스템을 제안하는 것을 목적으로 한다. 일반적인 자동판독 시스템의 사양을 정의하고 그 구현방법을 제안하였다. 응용 예로서 자궁경부암 진단용 DNA 칩을 대상으로 GenePix 스캐너 프로그램 환경에 적용하였다. 영상획득은 GenePix 의 라이브러리를 사용하여 HTML 언어로 구현하였고, 영상의 판단과 보고서 생성은 Microsoft Visual C++ 6.0를 사용하여 COM 형태로 구현하였다. 결과 보고서는 한글 2002 문서에 환자 정보와 결과 정보 등에 해당하는 곳에 미리 정의된 표지문자열들을 삽입하여 템플릿을 만들었다. 판독 시스템은 템플릿을 읽어들여 처리 결과의 내용으로 표지문자열들을 치환하여 보고서를 생성하였다. 제안한 시스템을 통해서 스캐닝을 통한 영상획득, 영상읠 판독, 결과 보고서 생성으로 구성된 전체 판독과정이 사용자의 개입 없이 자동으로 처리될 수 있었다. 본 시스템은 기존에 수작업을 자동화여 판독 시간을 단축하고 판독 기준을 정량화하여 진단용 DNA 칩이 대량검사 활용되는 공헌할 것으로 기대된다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.256-258
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• 2005

올리고뉴크레오타이드 서열의 디자인은 일반 분자 생물학 뿐만 아니라 DNA 컴퓨팅 분야에서도 중요한 문제이다. DNA나 RNA와 같은 생체 물질간의 화학반응을 이용하여 계산을 수행하는데 사용되는 염기 서열의 품질은 계산의 정확도에 큰 영향을 미치기 때문에, 문제의 특성에 따른 요구 조건에 안는 염기 서열을 디자인 하기위한 방법에 대해 여러 가지 연구가 있어왔다. 기존의 DNA 컴퓨팅을 위한 염기서열 디자인은 주어진 녹는점의 범위에서 단순히 서로 독립적인 염기서열들의 집합을 디자인 하거나, 분자생물학 실험에 사용되는 올리고 프로브나 프라이머 셋을 디자인 하는 것을 중심으로 이루어졌다. 반면, 본 논문에서는 세포에서 추출된 DNA/RNA 분자가 섞여있는 환경에서 어느 DNA/RNA 분자와도 흔성화 반응물 하지않는 범용 올리고뉴클레오타이드 태그를 디자인하는 간단한 유전 알고리즘을 제시하며, 이를 이용해서 디자인된 염기서열 결과를 제시한다.