• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.05a
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• pp.127-128
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• 2004

• Environmental Analysis Health and Toxicology
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• v.15 no.4
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• pp.131-137
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• 2000

The release of hazardous waste materials into the environment poses serious risks in humans and ecosystems. The risk assessment of environmental pollutants including hazardous chemicals requires a comprehensive measurement of hazard and exposure of the chemicals that can be achieved by toxicity evaluation using a biological system such as biomarkers. In this report we have tried to develop a biomarker used to elucidate a molecular basis of, and to monitor abnormal behaviors caused by diazinon in Japanese medaka (Oryzias latipes) as a model organism. First, an attempt was made to clone tyrosine hydroxylase gene from Japanese medaka that would be a candidate for a biomarker for neuronal modulations and behaviors. For monitoring experiments at behavioral and molecular biological levels, the fish were treated under different sublethal conditions of diazinon and their behavioral responses were observed . In this study we have successfully cloned a partial TH gene from the medaka fish through PCR screening of an ovary cDNA library. DNA sequencing analysis revealed that the amplified fragment was 327 bp encoding 109 amino acids. Comparing the DNA sequence of medaka TH with other species, TH gene revealed the DNA sequence was completely identical to that of rat TH. In the RT-PCR, 330 Up of mRNA was consistently amplified in all the treated samples including control There were no significant differences in the TH expression level regardless of treating concentrations (1∼5,000 ppb) and time (0∼48 hr) The reason appeared to be that RT-PCR was not performed using through a quantitative analysis normalized against an actin gene expression. Organ or tissue - specific detection of TH activity and mRNA as biomarkers will be a useful monitoring tool for neurobehavioral changes in fish influenced by toxic chemicals. Furthermore, quantitative analysis of locomotive patterns and its correlation with the neurochemical and molecular data would be highly useful in measuring toxicity and hazard ofvarious environmental pollutants.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.303-311
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• 2002

This study evaluated the concentrations of urinary metabolites of polycyclic aromatic hydrocarbons (PAHs) in industrial waste incineration workers. The effect of genetic polymorphisms of xenobiotic metabolism enzymes on urinary concentration of PAH metabolites was assessed. And, aromatic DNA adduct levels were also determined in total white blood cells. Fifty employees were recruited from a company handling industrial wastes located in Ansan, Korea: non-exposed group (n=21), exposed group (n=29). Sixteen ambient PAHs were determined by GC/MSD (NIOSH method) from personal breathing zone samples of nine subjects near incinerators. Urinary 1-hydroxypyrene glucuronide (1-OHPG), a major pyrene metabolite, was assayed by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11 (SFS/IAC). Multiplex PCR was used for genotyping for GSTMI/TI and PCR-RFLP for genotyping of CYP1A1 (MspI and Ile/Val). PAH-DNA adducts in peripheral blood WBC were measured by the nuclease P1-enhanced postlabeling assay. Smoking habit, demographic and occupational information were collected by self-administered questionnaire. The range of total ambient PAH levels were 0.00-7.00 mg/㎥ (mean 3.31). Urinary 1-OHPG levels were significantly higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs (p=0.006, by Kruskal-Wallis test). There was a statistically significant dose-response increase in 1-OHPG levels with the number of cigarettes consumed per day (Pearson correlation coefficient=0.686, p<0.001). Urinary 1-OHPG levels in occupationally exposed smoking workers were highest compared with non-occupationally exposed smokers (p=0.053, by Kruskal-Wallis test). Smoking and GSTMI genotype were significant predictors for log-transformed 1-OHPG by multiple regression analysis (overall model R²=0.565, p<0.001), whereas smoking was the only significant predictor for log-transformed aromatic DNA adducts (overall model R²=0.249, p=0.201). Aromatic DNA adducts was also a significantly correlation between log transferred urinary 1-OHPG levels (pearson's correlation coefficient=0.307, p=0.04). However, the partial correlation coefficient adjusting for Age, Sex, and cigarette consumption was not significant (r=0.154, p=0.169). The significant association exists only in individuals with the GSTMI null genotype (pearsons correlation coefficient=0.516, p=0.010; partial correlation coefficient adjusting for age, sex, and cigarette consumption, r=0.363, p=0.038). Our results suggest that the significant increase in urinary 1-OHPG in the exposed workers is due to higher prevalence of smokers among them, and that the association between urinary PAH metabolites and aromatic DNA adducts in workers of industrial waste handling may be modulated by GSTMI genotype. There results remain to be confirmed in future larger studies.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.66-74
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• 2004

In order to clarify intra-and inter-specific variation of Korean Rana species, the partial DNA sequences of mitochondrial 16S rDNA gene were determined from 6 Korean and 1 Japanese Rana species, DNA sequences from Korean and Japanese species were comparison-analysed within, and also with the sequences from three species of Japanese brown frogs. DNA similarities were calculated as 91.3∼97.3％ among brown frog (R. amurensis coreana, R. dybowskii and R. huanrenensis), as 96.11∼97.26％ among pond frogs (R. nigromaculata and R. planeyi chosenica). Genetic distance of pond frog and wrinkle fyog (R. rugosa) were near than that of pond frog and brown frog. Two clusters were formed brown frogs and the other group by neigh-bor-joining and maximum-likelihood analysis, also the populations of R. nigromaculata were well distinguished between Korean peninsula and Korean island. But result from maximum-likelihood analysis slightly differed from neighbor-joining to cluster of R. rugosa. Further analyses for their population will be necessary to study the phylogenetic status.

• Ocean and Polar Research
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• v.46 no.3
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• pp.131-142
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• 2024

Ocean change due to anthropogenic activities and climate change are causing a decline in coldwater fish species and emergence of subtropical fish species in Korean waters. Therefore, environmental change-dependent time-space distribution of fishery resources in Korea, which has a big fisheries industry, needs to be investigated. Environmental DNA (eDNA) metabarcoding is an environmentally noninvasive method for understanding the spatiotemporal distribution of marine organisms at high spatial resolution. The highly variable cytochrome oxidase-1 (CO1) gene is used in eDNA studies for species identification across diverse taxa. However, it exhibits genetic differences depending on geographical distribution. For improving the accuracy of eDNA research, the CO1 database should be expanded by incorporating sequence information for individuals inhabiting the Korean seas. Here, 106 biological samples from the Yellow Sea were identified morphologically and their nucleotide sequences were compared with those in the GenBank. Most sequences were 100% identical with those in the GenBank. In most samples, the morphological and molecular identification results were consistent, indicating the utility of CO1. However, some nucleotide sequences differed from those in the database. Amino acid sequences translated from nucleotide sequences with less than 97% similarity showed high similarity to the amino acid database, indicating intraspecies variation due to "silent mutations". These results highlight the need for a sequence database of fishery resources in Korean coastal waters to improve the reliability of eDNA studies using CO1. However, because of the same CO1 sequences in several species, genetic markers need to be developed and the database should be supplemented with more sequences for reliable high-resolution eDNA studies.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.144-156
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• 2016

Soil is a dynamic biological system, in which it is difficult to determine the composition of microbial communities. Knowledge of microbial diversity and function in soils are limited because of the taxonomic and methodological limitations associated with studying the organisms. In this review, approaches to measure microbial diversity in soil were discussed. Research on soil microbes can be categorized as structural diversity, functional diversity and genetic diversity studies, and these include cultivation based and cultivation independent methods. Cultivation independent technique to evaluate soil structural diversity include different techniques such as Phospholipid Fatty Acids (PLFA) and Fatty Acid Methyl Ester (FAME) analysis. Carbon source utilization pattern of soil microorganisms by Community Level Physiological Profiling (CLPP), catabolic responses by Substrate Induced Respiration technique (SIR) and soil microbial enzyme activities are discussed. Genetic diversity of soil microorganisms using molecular techniques such as 16S rDNA analysis Denaturing Gradient Gel Electrophoresis (DGGE) / Temperature Gradient Gel Electrophoresis (TGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP), Single Strand Conformation Polymorphism (SSCP), Restriction Fragment Length Polymorphism (RFLP) / Amplified Ribosomal DNA Restriction Analysis (ARDRA) and Ribosomal Intergenic Spacer Analysis (RISA) are also discussed. The chapter ends with a final conclusion on the advantages and disadvantages of different techniques and advances in molecular techniques to study the soil microbial diversity.

• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.26-31
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• 2005

The detection and the regulation of man-made synthetic chemicals and the establishment of toxicity that may pose a genetic hazard in our environment are subjects of great concern because of its close correlation between environmental contamination and human health. Since the tens of thousands of man-made chemicals that have been introduced into the environment in the last few decades must also be tested for their damaging effect on DNA, the agents that cause this damage must be identified.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.115-115
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• 2001

Regular green tea consumption has been associated with a reduced risk of cancer, partly via antioxidant effects of green tea in protecting cellular components against free radical. In the present study, we evaluated the effect of green tea extract (GTE) on oxidative damage to DNA in CHL cells.(omitted)

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.256.1-256
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• 2001

No Abstract, See Full Text

• Journal of Species Research
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• v.1 no.1
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• pp.1-3
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• 2012

A new species, Zabelia densipila M.-P. Hong, Y.-C. Kim & B.Y. Lee (Linnaeaceae) is described from Gangwon-do, Korea and illustrated. The new taxon resembles Z. biflora (Turcz.) Makino, but it can be distinguished by its different flowering seasons, ovaries with densely long-pilose hairs, and sequence differences in nuclear ribosomal DNA and chloroplast DNA coding regions.