• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.289-295
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• 2002

This study was conducted to quantify of micronucleus frequencies in human umbilical cord blood by supravital staining method with acridine orange, and to find some factors that affected on micronucleus frequncies in humans. In this study, we used umbilical cord blood of new born infants that have sufficient reticulocytes compared with adult peripheral blood. The cord bloods were taken after childbirth from 60 normal infants in industrial and coastal region in Korea. The total of 3 ${mu}ell$ cord blood was applied to slide coated with acridine orange, and micronuclei were observed under fluorescent microscopy. Demographic factors and independent variables were collected from mothers by questionnaire. The frequencies of micronuclei in umbilical cord blood of new born infants were 0-5 per 2,000 reticulocytes by supravital staining method, and mean value and standard deviation were 1.75$\pm$0.97. There were no significant difference by the regions, smoking habits of father or mother. However, age of mother showed significant positive correlation with frequencies of micronuclei (p<0.05). Smoking at home by fathers also was found as a significant variable by muliple regression analysis. Therefore, further studies would be needed for genotoxicological evaluation of new born infants by microneuli test using supravital staining method.

• Environmental Mutagens and Carcinogens
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• v.23 no.1
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• pp.16-22
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• 2003

Single nucleotide polymorphisms (SNPs) are alterations in DNA base that occur most frequently throughout the human genome. The SNPs of DNA repair genes, hMLH1, hMSH2 and ATM, among 100 Korean people were analyzed using Dynamic Allele specific Hybridization (DASH) techniques. Mutation at the position of exon 38 (GA) and exon 10 (CG) of ATM gene, mutation at the position of exon 8 (AG), and exon 1 (AG) of hMLH1 gene and exon 14 (AG) of hMSH2 gene were investigated. No mutation at the selected position of ATM gene and hMSH1 gene was found. However, while there was no mutation at the position of exon of hMSH2 gene, mutation was found at the promotion region (CT) with the frequency of 24% CC, 36% CT and 62% TT genotyes. This results might be used as baseline data for research on SNP of Korean population.

• Environmental Mutagens and Carcinogens
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• v.25 no.4
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• pp.150-156
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• 2005

Analysis of chromosome aberration (CA) and cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of nurses exposed to low levels of anticancer drug and Ethylene Oxide(EO) gas in a hospital were performed. The frequency of CA was increased in the exposed compared to the controls whereas no increase of the frequency of MN was found. The frequencies of chromatid type CA were 1.2, 3.91 and 9.67 per 500 cells in the controls, workers exposed to anticancer drug and workers exposed to EO, respectively. Lower frequency of CA in nurses handling anticancer drugs with safety covers compared to those without safety covers was observed, but it was not statistically significant. The frequency of CA in nurses handling anticancer drugs increased by the frequency of mixing anticancer drugs. Poisson regression analysis showed a significant association of the frequency of chromatid type CA with age, duration of wort exposure to anticancer drug and EO gas exposure, but no association of the frequency of chromosome type CA with any variables. The results suggested that there were associations between CA and the occupational exposure to low levels of anticancer drug and EO gas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.247-253
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• 1997

Development of soybean cultivars with great nodulation and high nitrogen fixation activity, derived mostly from mutagenesis, may decrease inputs of chemical fertilizer nitrogen into the soil-plant system. Soybean seeds (cv. Jangyupkong, Hwanggeumkong, and Geomjungkong 1) were treated with three different levels of EMS (ethyl methanesulfonate) concentration(30, 50, and 70mM). Increasing the doses of EMS resulted in decreased field emergence rate of seeds, whereas it did not increase M$_2$ mutation frequencies. This indicated that the most efficient concentration of EMS was 30mM for generating mutants. Extensive mutagenesis of Sinpaldalkong 2 with 30mM EMS was undertaken to isolate soybean mutants with greater nodulation. Approximately 8, 200 M$_2$ families were screened for greater nodulation on 5 mM nitrate after inoculation with Bradyrhizobium japonicum strain YCK213-KFCC-10728. Mutant SS-2 nodulated more than the wild type. Comparison of supernodulation between SS-2 and two nts mutants(nts 1007 and nts 1116) revealed that SS-2 showed the supernodulation character at an earlier growth stage than the two nts mutants. Further studies should be needed to characterize the difference in timing of nodulation between SS-2 and nts mutants.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.337-344
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• 2000

Germ-line mutations at DNA repair loci confer susceptibility to colon cancer in hereditary non-polypopsis colorectal cancer. Somatic loss of DNA mismatch repair gene has been reported in a large variety of other tumor types. Replication errors(RERs) judged by microsatellite instability(MSI) and its associated mutations have been recognized as an important mechanism in various tumor types. To investigate associations between MSI and oral squamous cell carcinoma, the frequency of MSI using 12 microsatellite markers were analyzed for the series of oral tumors. Of 17 tumors, 8 cases(47%) did not show instability at any of the 12 loci; 5(29%) showed instability at $2{\sim}3$ loci; and 4(24%) showed instability above 4 loci. The 4 cases showing widespread MSI did not differ from those without evidence of instability in terms of age at diagnosis, degree of differentiation, metastasis to lymph node, tumor location or the presence of mutations in the p53 tumor suppressor gene. DCC and D17S 796 were the most frequently detected in MSI analysis. There were no correlation between smoking and MSI frequency, instead, smoking was suggested to increase the mutation rate of p53 and development of oral carcinomas.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.53-57
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• 2011

Purpose: Wilson disease is an autosomal recessive disorder which causes excessive copper accumulation in the hepatic region. So far, ATP7B gene is the only disease-causing gene of Wilson disease known to date. However, ATP7B mutations have not been found in ~15% of the patients. This study was performed to identify any causative gene in Wilson disease patients without an ATP7B mutation in either allele. Materials and Methods: The sequence of the coding regions and exon-intron boundaries of the five ATP7B-interacting genes, ATOX1, COMMD1, GLRX, DCTN4, and ZBTB16, were analyzed in the 12 patients with Wilson disease. Results: Three nonsynonymous variants including c.1084A>G (p.Thr362Ala) in the exon 12 of the DCTN4 gene were identified in the patients examined. Among these, only p.Thr362Ala was predicted as possibly damaging protein function by in silico analysis. Examination of allele frequency of c.1084A>G (p.Thr362Ala) variant in the 176 patients with Wilson disease and in the 414 normal subjects revealed that the variant was more prevalent in the Wilson disease patients (odds ratio [OR]=3.14, 95% confidence interval=1.36-7.22, P=0.0094). Conclusion: Our result suggests that c.1084A>G (p.Thr362Ala) in the ATP7B-interacting DCTN4 gene may be associated with the pathogenesis of Wilson disease.

• Journal of Life Science
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• v.13 no.3
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• pp.252-257
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• 2003

The genetic variabilities of second chromosomes of Drosophila melanogaster concealed in Busan natural and experimental populations have been analyzed by the Cy//Pm method. The experimental population was composed of D. melanogaster which had the lethal-free second chromosome, collected Sasang natural population in 1982. The frequencies of deleterious genes were estimated to be 14.3∼25.4% in Busan natural population and 26.5∼27.2% in experimental population. The allelism rates in lethal genes isolated from the natural and experimental populations were calculated to be about 0.76% and 9.76∼14.17%, respectively. The value of elimination by the frequencies of deleterious genes and allelism rate was 0.0106and the effective population size estimated to be about 430 flies at the 6570 days population.

• Microbiology and Biotechnology Letters
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• v.16 no.6
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• pp.463-467
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• 1988

In this study characterization of spontaneous Lac$^-$ mutant of Lactobacillus casei YIT 9018 was investgated. The frequency of occuring the spontaneous Lac$^-$ mutant cells from stok culture strains was approximately 0.5% in MRS Media and 0.29% in 10% nonfat dried milk, ohterwise, that from pure Lac$^+$ colony it was 0.25% in MRS Media and 0.1% in l0% nonfat dried milk. In the physiological deference the spontaneous Lac$^-$ mutants were defective in lactose and/ or galactose-fermenting ability and also needed longer time for coagulation of nonfat dried milk than wild type.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.37-43
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• 2004

This study was carried out to investigate PSS (Porcine Stress Syndrome) with the PSE (Pale, Soft, Exudative) in 319 different pigs(Yorkshire 150; Landrace 89 and Duroc 80). The PCR-RFLP method was adapted to detect the ryanodine receptor (RYR 1) gene mutation and to estimate the genotype frequency of the RYR1 gene in breeding pig population. The DNA samples were collected from hair follicles of pigs of Yorkshire, Landrace and Duroc. After DNA amplification by PCR, the PCR products were digested by restriction enzyme, Cfo I. Primary PCR products of ryanodine receptor gene were length of 659 bp in hair follicle and their second PCR products were length of 522 bp in hair follicle. The exon region (522 bp) including point mutation ($C \arrow T; Arg \arrow Cys$) in the porcine ryanodine receptor gene, which is a causal mutation for PSS, was digested with Cfo I restriction enzyme. The RYR1 gene was classifed into three genotypes by agarose gel electrophoresis. The normal homozygous (NN) individuals showed two DNA fragments consisted of 439 and 83 bp. The mutant homozygous (nn) individuals showed only one DNA fragment 522 bp. In addition, all three fragments (522, 439 and 83 bp) were showed in heterozygous (Nn) carrier animals. The normal homozygous (NN), heterozygous (Nn) and mutant homozygous (nn) were 98.00, 2.00 and 0.00% in Yorkshire pigs, 87.64, 11.24 and 1.12% in Landrace, 100.00, 0.00 and 0.00% in Duroc, respectively. The gene frequencies of N and n were 0.990 and 0.010 in Yorkshire pigs, 0.933 and 0.067 in Landrace, 1.000 and 0.000 in Duroc, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.910-916
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• 2002

As the utilization of medicinal herbs in food and bio-industry increases, safe hygienic technologies for them are demanded. To consider the possibility of application of radiation technology for this purpose, the genotoxi-cological safety of three r -irradiated medicinal herbs were studied. Astragali Radix, Atractylodes Rhizoma and Cimicifugae Rhizoma were irradiated at 10 kGy, and then were extracted with hot water. The genotoxicity of the extracts was examined in two short-term in vitro tests: (1) Salmonella reversion assay (Ames test) in strains of TA98 and TA100; (2) Micronucleus test in cultured Chinese hamster ovary (CHO) cells. The extract was treated at maximum doses of 5 mg/plate in Salmonella reversion assay, and 1 mg/mL in micronucleus test where growth of CHO cells was inhibited by 50%. In Salmonella reversion assay with or without metabolic activation, both ex-tracts of irradiated and non-irradiated herbs showed no significant differences in formation of revertant colonies compared with the negative control. And also in micronucleus test, the incidences of micronucleus in CHO cells cultured with extracts of irradiated herbs were almost same as negative control in less than 3%. These results of two in vitro tests suggest that ${\gamma}$-irradiated herbs do not show mutagenicity and cytogenetic toxicity. Further tests of in vivo genotoxicity and chronic toxicity are needed to ascertain the safety of ${\gamma}$-irradiated herbs.