• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.49-53
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• 2004

• 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.

• ALGAE
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• v.28 no.3
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• pp.213-231
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• 2013

Amphidinium massartii Biecheler is an epiphytic and toxic dinoflagellate. Prior to the present study, A. massartii has been reported in the waters off the Mediterranean, Australian, USA, and Canadian coasts. We isolated Amphidinium cells from the coastal waters of Jeju Island, Korea and their morphology and rDNA sequences indicated that they were A. massartii. Herein, we report for the first time the occurrence of A. massartii in the waters of the temperate region in the northwestern Pacific Ocean. The large subunit (LSU) rDNA sequences of the Korean strains were 0.7% different from those of an Australian strain of A. massartii CS-259, the closest species, but were 4.1-5.8% different from those of the other Australian strains and the USA strains of A. massartii and from those of Amphidinium sp. HG115 that was isolated from subtropical Okinawan waters. In phylogenetic trees based on LSU, internal transcribed spacer, small subunit rDNA, and cytochrome b sequences, the Korean strains belonged to the A. massartii clade, which was clearly divergent from the A. carterae clade. The morphology of the Korean A. massartii strains was similar to that of the originally described French strain and recently described Australian strain. However, we report for the first time here that scales were observed on the surface of the flagella. In conclusion, the Korean A. massartii strains have unique rDNA sequences, even though they have a very similar morphology to that of previously reported strains. This report extends the known range of this dinoflagellate to the temperate waters of the northwestern Pacific Ocean.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.71-76
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• 1998

Exposure to environmental toxicants can cause cellular problems including the interference of DNA repair processes which may lead to the development of cancer. The existence of toxicant-induced DNA repair abnormality was investigated using mice exposed in vivo to genotoxic chemicals and then challenging their exposed lymphocytes in vitro with bleomycin. The repair of bleomycin-induced DNA damage as estimated by the frequency of chromosome aberrations was determined. Our data indicates that the observed aberration frequencies after in vivo exposure to N-methyl-N'-nitro-N-nitnsoguanidine (MNNG) and in vitro challenge with bleomycin are consistently higher than expected. The enhanced response is not due to the induction of chromosome damage by 25 or 50 mg/kg MNNG since the chemical did not cause chromosome aberrations in lymphocytes of these mice. The observed response after the combined exposure to benzo[a]pyrene (BP) and bleomycin was significantly lower than expected with low in vivo doses of BP (50 mg/kg) and then significantly higher than expected with the high doses (200 mg/kg). We interpret our data to indicate that in vivo exposure to genotoxic agents can cause abnormal DNA repair activities. The response is, however, independent of the clastogenic activities of the inducing chemicals, but dependent upon the inducing agents and on the exposure doses.

• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.6-11
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• 2002

3.3'-Dichlorobenzidine(DCB) has be shown carcinogenic in several animals, and the development of non-invasive biomonitoring method in workers exposed with it is a very important subject. DNA adduct is a good biomarker for biomonitoring about carcinogens exposure, and lymphocytes is a good non-invasive samples. So we studied to analyze metabolites in blood lymphocytes of female Sprague-Dawley rats exposed orally with DCB(20, 30, and 40 mg/kg wt.) for 3 weeks. For analysis of them, we isolated DNA adducts from blood lymphocytes by using the enzymes method in /sup 32/P-postlabeling, and measured them by using gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM). 4-aminobiphenyl and phenanthrene-d/sub 10/ were added as internal standard for blank sample. Standard metabolites of DCB were synthesized with using pyridine and acetic acid which were promoter and controller in acetylation of DCB. And they were used for calibration curve. Our results showed two kinds of metabolites in DNA adducts of blood lymphocytes. They were N-acetyl 3,3'-dichlorobenzidine(acDCB) and N,N'-diacetyl 3,3'-dichiorobenzidine(di-acDCB ). They were combined with DNA at the same time as an acetyl of it was removed. So we measured DCB and acDCB for two kinds of metabolites in DNA adducts of blood lymphocytes. Our results showed the levels of DCB were 1.46∼2.26 times more than that of acDCB. And also the levels of metabolites in 20, 30 and 40 mg/kg wt. were gradually increased with going days from 1st to 3rd week. They are 1.66, 1.38 and 0.90 times in total metabolites, 1.76, 1.49 and 1.02 times in DCB, and 1.51, 1.22 and 1.28 times in acDCB. In conclusion, the results of this study showed DCB exposed to rats formed DNA adduct in blood lymphocytes after acetylated to N-acetyl 3.3'-dichloro benzidine(acDCB) and N,N'-diacetyl 3,3'-dichlorobenzidine(di-acDCB), and they could be analyzed by us ing gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM).

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.247-256
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• 2021

Understanding the selective feeding behavior of zooplankton on phytoplankton is essential for evaluating the nutrient cycle and energy flow in the food web. Although many studies have been conducted regarding the feeding behaviors of zooplankton through gut content analyses, there are limitations in the visual identification of digested contents using a microscope. DNA techniques have been applied to overcome these limitations since they can detect and amplify small amounts of prey DNA remaining in the gut contents. We designed a method to extract prey DNA from the gut contents of the whole body of the copepod specimen and tested the resolution of DNA identification for the prey phytoplankton. The common brackish species, Sinocalanus tenellus, were collected from Saemangeum Reservoir in different sites and seasons, and gut content DNA was extracted using 2.5% bleach treatment for 2 min for removal of potential contamination sources existing in preserved specimens without dissolution of the body. The sequences of the extracted gut contents were confirmed using BLASTn suite based on the NCBI database. The phytoplankton species detected in the gut showed temporal and spatial differences. Although DNA analysis of small copepod gut contents has been suggested as an effective method to examine the dynamics of primary prey sources at the genus or species level, uncertainties such as misidentification and limitations in the detailed information of the composition still exist.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.181-190
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• 2007

The phylogenie relationships existing among 14 parasitic Platyhelminthes in the Republic of Korea were investigated via the use of the partial 28S ribosomal DNA (rDNA) D1 region and the partial mitochondrial cytochrome c oxidase subunit 1 (mCOI) DNA sequences. The nucleotide sequences were analyzed by length, G + C %, nucleotide differences and gaps in order to determine the analyzed phylogenie relationships. The phylogenie patterns of the 28S rDNA D1 and mCOI regions were closely related within the same class and order as analyzed by the PAUP 4.0 program, with the exception of a few species. These findings indicate that the 28S rDNA gene sequence is more highly conserved than are the mCOI gene sequences. The 28S rDNA gene may prove useful in studies of the systematics and population genetic structures of parasitic Platyhelminthes.

• Biomedical Science Letters
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• v.11 no.2
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• pp.227-235
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• 2005

It has been reported that endurance performance is influenced by various environmental and genetic factors. In view of an important role of human mitochondrial DNA (mtDNA) as a candidate for endurance performance, this study focused on the relationships between $VO_{2max}$ value as a measure of endurance performance or other associated phenotypes and four mtDNA restriction fragment length polymorphisms (RFLPs) (Bam HI, Hinc II1, Hinc II2 and Nci I) in the NADH dehydrogenase subunit 5 and one (Kpn I) in the D-loop region of mtDNA. MtDNA was purified from buffy coat in human peripheral blood, and PCR-RFLP analysis was performed to estimate the allele frequencies of each polymorphism in the mtDNA. There were no significant differences in allele distributions of all polymorphisms studied between male athletes and controls, respectively (P>0.05). However, the Kpn I polymorphism was significantly associated with diastolic blood pressure level in male athletes, respectively (P<0.05). Therefore, our results suggest that this polymorphism might be one of the factors modifying inter-individual difference in cardiovascular risk. Further studies using larger sample size will be required to generalize these results from the study described herein.

• Korean Journal of Environmental Biology
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• v.23 no.4
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• pp.379-382
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• 2005

The new cationic meso-substituted N-quarternized 4-pyridylporphyrins and their metal derivatives were synthesized as novel chemotherapeutics. The level of DNA damage induced by porphyrins TOBut4PyP, TOBut4PyP, TOEt4PyPMn and TOBut4PyPMn and its dependence on the chemical structure of compounds were analyzed by the Comet-assay. On the base of data obtained, the investigated porphyrins may be arranged by their genotoxic activity in the following order: TOEt4PyP>TOEt4PyPMn>TOBut4PyP>TOBut4PyPMn. Thus, i) the genotoxicity of the Mn-derivatives of TOEt4PyP and TOBut4PyP is higher than the original porphyrins and ii) the genotoxicity of TOEt4PyP and TOEt4PyPMn is increased after substitution of a butyl radical for ethyl one. The applied Comet-assay permits to reveal the dependence of DNA damage induction on the chemical structure of porphyrins.

• Interdisciplinary Bio Central
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• v.3 no.1
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• pp.1.1-1.6
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• 2011

Recently, with the progress of genome sequencing, materials and information for research on tomato (Solanum lycopersicum) have been systematically organized. Tomato genomics tools including mutant collections, genome sequence information, full-length cDNA and metabolomic datasets have become available to the research community. In Japan, the National BioResource Project Tomato (NBRP Tomato) was launched in 2007, with aims to collect, propagate, maintain and distribute tomato bioresources to promote functional genomics studies in tomato. To this end, the dwarf variety Micro-Tom was chosen as a core genetic background, due to its many advantages as a model organism. In this project, a total of 12,000 mutagenized lines, consisting of 6000 EMS-mutagenized and 6000 gamma-ray irradiated M2 seeds, were produced, and the M3 offspring seeds derived from 2236 EMS-mutagenized M2 lines and 2700 gamma-ray irradiated M2 lines have been produced. Micro-Tom mutagenized lines in the M3 generation and monogenic Micro-Tom mutants are provided from NBRP tomato. Moreover, tomato cultivated varieties and its wild relatives, both of these are widely used for experimental study, are available. In addition to these bioresources, NBRP Tomato also provides 13,227 clones of full-length cDNA which represent individual transcripts non-redundantly. In this paper, we report the current status of NBRP Tomato and its future prospects.