• Title/Summary/Keyword: reverse mutation

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Identification and Characterization of New Copia-like Retrotransposon Osr1 in Rice

  • Lee, Yong-Hwan;Jwa, Nam-Soo;Park, Sook-Young;Park, Chan-Ho;Han, Seong-Sook
    • The Plant Pathology Journal
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    • v.19 no.1
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    • pp.57-63
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    • 2003
  • An insertion sequence identified as a solo long terminal repeat (LTR) of a new rice copia-like retrotransposon was detected in the ORE of the Pi-b gene from the rice cv. Nipponbare, and was designated as Osr1. Osr1 consists of a 6386 bp nucleotide sequence including 965 bp LTRs on both ends with an 82% nucleotide sequence identity to the wheat Tarl retrotransposon on reverse transcriptase. Nucleotide divergence was noted among the individual LTRs, as well as the coding region of Osr1. Various restriction fragment length polymorphism (RFLP) of LTR were detected in indica cultivars, whereas, only a few could be detected in the japonica cultivars. The population of Osr1 is lower in the wild-type rice compared with that in the domesticated cultivars. The insertion of LTR sequence in the h-b gene in the susceptible cultivar suggested that retro-tyansposon-mediated insertional mutation might play an important role in the resistance breakdown, as well as in the evolution of resistance genes in rice.

Study on Mutagenicity of DehydroevodiamineㆍHCl(DHED) (치료제 DehydroevodiamineㆍHCl(DHED)의 변이원성 연구)

  • 성이숙;정성윤;정주연;채규영;진미령;최봉웅;장병모;김대경
    • YAKHAK HOEJI
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    • v.46 no.3
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    • pp.208-212
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    • 2002
  • Dehydroevodiamine HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in the scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for the Alzheimer's disease and the vascular type of dementia. In order to evaluate the mutagenic potential of DHED, Salmonella typhimurium reversion assay, chromosomal aberration test on Chinese hamster lung cells, in vivo micronucleus assay using mouse bone marrow cells, and comet assay were performed. DHED did not increase the number of revertant in the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98, TA100. DHED HCl, at concentration of 5 and 10 $\mu\textrm{g}$/mι, increased the number of chromosome aberrated Chinese hamster lung cells with 5 and 10%, respectively. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocyte was observed in ICR mice orally administered with DHED. DHED was tested for ability to induce genotoxic effect in L5178Y cells (mouse lymphoma cells) using the single cell gel electrophoresis assay (comet assay). In comet assay, tail moment did not increase in L5178Y cells treated with 10, 100, 300 $\mu$M DHED.

Cloning and Characterization of the Orotidine-5'-Phosphate Decarboxylase Gene (URA3) from the Osmotolerant Yeast Candida magnoliae

  • Park, Eun-Hee;Seo, Jin-Ho;Kim, Myoung-Dong
    • Journal of Microbiology and Biotechnology
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    • v.22 no.5
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    • pp.642-648
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    • 2012
  • We determined the nucleotide sequence of the URA3 gene encoding orotidine-5'-phosphate decarboxylase (OMPDCase) of the erythritol-producing osmotolerant yeast Candida magnoliae by degenerate polymerase chain reaction and genome walking. Sequence analysis revealed the presence of an uninterrupted open-reading frame of 795 bp, encoding a 264 amino acid residue protein with the highest identity to the OMPDCase of the yeast Kluyveromyces marxianus. Phylogenetic analysis of the deduced amino acid sequence revealed that it shared a high degree of identity with other yeast OMPDCase homologs. The cloned URA3 gene successfully complemented the ura3 null mutation in Saccharomyces cerevisiae, revealing that it encodes a functional OMPDCase in C. magnoliae. An enzyme activity assay and reverse transcription polymerase chain reaction indicated that the expression level of the C. magnoliae URA3 gene in S. cerevisiae was not as high as that of the S. cerevisiae URA3 gene. The GenBank accession number for C. magnoliae URA3 is JF521441.

Cloning and Characterization of a Glyoxalase I Gene from the Osmotolerant Yeast Candida magnoliae

  • Park, Eun-Hee;Lee, Dae-Hee;Seo, Jin-Ho;Kim, Myoung-Dong
    • Journal of Microbiology and Biotechnology
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    • v.21 no.3
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    • pp.277-283
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    • 2011
  • Glyoxalase I catalyzes the conversion of methylglyoxal to S-D-lactoylglutathione in the presence of glutathione. The structural gene of glyoxalase I (GLO1) was cloned from an osmotolerant yeast, Candida magnoliae, which produces a functional sweetener, erythritol, from sucrose. DNA sequence analysis revealed that the uninterrupted open reading frame (ORF) of C. magnoliae GLO1 (CmGLO1) spans 945 bp, corresponding to 315 amino acid residues, and shares 45.2% amino acid sequence identity to Saccharomyces cerevisiae Glo1. The cloned ORF in a multicopy constitutive expression plasmid complemented the glo1 mutation of S. cerevisiae, confirming that it encodes Glo1 in C. magnoliae. The responses of CmGLO1 to environmental stresses were different from those of S. cerevisiae, which only responds to osmotic stress. An enzyme activity assay and reverse transcription polymerase chain reaction revealed that the expression of CmGLO1 is induced by stress inducers such as methylglyoxal, $H_2O_2$, KCl, and NaCl. The GenBank Accession No. for CmGLO1 is HM000001.

Biosafety and Toxicological Evaluation of Tissue-Cultured Echinacea purpurea Adventitious Roots

  • Murthy, Hosakatte Niranjana;Park, So-Young;Lee, Eun Jeong;Paek, Kee Yoeup
    • Horticultural Science & Technology
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    • v.33 no.1
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    • pp.124-132
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    • 2015
  • Echinacea purpurea (L.) Moench (purple cone flower) is an important medicinal plant; it can enhance immunity, relieve pain, and reduce inflammation, and also has hormonal, antiviral, and antioxidant effects. Adventitious root biomass of Echinacea purpurea was produced in commercial-scale bioreactors for use as a dietary supplement in the food industry and in traditional medicine. Biosafety and toxicological evaluations of tissue-cultured Echinacea purpurea adventitious roots (TCEPARs) were performed. Reverse mutation and chromosomal aberration tests showed no significant mutagenicity. Furthermore, repeated four-week oral dose tests performed in Sprague-Dawley rats did not show any notable changes in the general behavior of the rats, in the gross appearance of their internal organs, or in their mortality rate. There were no differences between the control group and the treatment group in parameters such as absolute body weight, hematology, blood chemistry, and absolute and relative organ weights. These findings indicate that TCEPARs are safe and nontoxic when consumed at an average dietary level and can be used as raw material for traditional medicine and the food industry.

A Study on the Screening of the Novel Genes Associated with Lysosomal Trafficking and Mutation Detection in Fibroblasts of the Patients with Mucolipidosis type II and III (리소좀 교통 이상을 초래하는 뮤코지방증 2형과 3형 환자의 섬유아세포를 이용한 신규 유전자 탐색 및 돌연변이에 대한 연구)

  • Song, Seng Mi;Chang, Soo Hee;Paik, Kyung Hoon;Jin, Dong-Kyu
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.5 no.1
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    • pp.65-75
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    • 2005
  • Purpose: To understand genetic differences and similarities between mucolipidosis and control. Methods: Using the fibroblast of the mucolipidosis II and control, forward and reverse subtracted libraries were constructed. Among these clones, we investigated mutations in the GNPTA (MGC4170) gene, which codes for the ${\alpha}/{\beta}$ subunits of phosphotransferase, and in the GNPTAG gene, which codes for the ${\gamma}$ subunits in 5 Korean patients with mucolipidosis type II or IIIA. Result: Several differentially expressed cDNAs were cloned and their sequences were determined. Mutation analysis of the interested gene, GNPTA was performed and we identified 7 mutations in the GNPTA gene, but none in the GNPTAG gene. The mutations in type II patients included p.Q104X(c.310C>T), p.R1189X(c.3565C>T), p.S1058X(c.3173C>G), p.W894X(c.2681G>A) and p.H1158fsX15(c.3474_3475delTA), all of which are non-sense or frame shift mutations. However, a splicing site mutation, IVS13+1G>A (c.2715+1G>A) was detected along with a non-sense or a frame shift mutation (p.R1189X or p.E858fsX3(c.2574_2575delGA)) in two mucolipidosis type IIIA patients. Conclusion: This report shows that mutations in the GNPTA gene coding for the ${\alpha}{\beta}$subunits of phosphotransferase, and not mutations in the GNPTAG gene, account for most of mutations found in Korean patients with mucolipidosis type II or IIIA.

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Characterization of Bruton's Tyrosine Kinase Genetic Mutations in One Korean X-linked Agammaglobulinemia Family (반성 열성 범저감마글로불린혈증 1가계 3환자의 Bruton's Tyrosine Kinase 유전자 변이 및 임상 양상)

  • Jo, Eun-Kyeong;Song, Chang-Hwa;Park, Jeong-Kyu;Baek, Young-Jong;Rhu, Hye-Young;Lee, Jae-Ho;Hwang, Tai-Ju;Kook, Hoon
    • Clinical and Experimental Pediatrics
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    • v.45 no.2
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    • pp.183-191
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    • 2002
  • Purpose : X-linked agammaglobulinemia(XLA) is an immunodeficiency caused by abnormalities in Bruton's tyrosine kinase(Btk), and is characterized by a deficiency of peripheral blood B cells. We studied the cytoplasmic expression of Btk protein and analyzed the Btk gene in peripheral blood mononuclear cells from two siblings and one cousin with XLA, as well as additional family members. Methods : Btk protein expression was analyzed by flow cytometry. Isolation of the coding sequence of the Btk gene was performed by amplification using the reverse transcription-polymerase chain reaction(RT-PCR) technique. Sequence alterations were screened by the single-stranded conformation polymorphism(SSCP) method and characterized by standard sequencing protocols. Results : Cytoplasmic expression of Btk protein in monocytes was not detected in three patients with XLA. In addition, Btk protein analysis clearly showed cellular mosaicism in monocytes from four obligate carriers, findings further supported by SSCP. A single base pair mutation(T to C) in Btk-exon three, which encodes the PH domain, was identified in four XLA patients. A diagnostic sequencing analysis was established to detect heterozygotic pattern in 4 carrier females. Furthermore, we found significant clinical heterogeneity in individuals with the same gene mutation. Conclusion : The implicating genetic alteration provided valuable clues to the pathogenesis of XLA in Korea and the flow cytometric analysis was suggested as a useful tool for rapid detection of XLA patients and carriers. The present study has identified a genetic mutation in the Btk coding region and demonstrated heterogeneity in clinical manifestations among patients with the same mutation. A flow cytometric analysis was found to be informative in establishing a deficiency of Btk protein in both patients and carriers and is recommended as a frontline procedure in the molecular diagnosis and work-up of XLA.

Studies on the Genetic Toxicity of Guh Sung Y.L.S.-95 (목초액 (거성 Y.L.S-95)의 유전독성에 관한 연구)

  • Lee Soo-Yong;Li Guang-Yong;Yin Hu-Quan;Jung Eun-Jung;Kim Youn-Su;Lee Hye-Young;Lee Byung-Hoon
    • Journal of Food Hygiene and Safety
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    • v.21 no.2
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    • pp.107-112
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    • 2006
  • Guh Sung Y.L.S-95 (GS95) is a kind of polyacidic solution, which contains acetic acid as a main component. We investigated in the present study tile genetic toxicity of GS95 according to the standard operation procedure from Korean Institute of Toxicology. In the Salmonella typhimurium reverse mutation assay using TA1535, TA1537, TA98 and TA100, GS95 did not induce mutation up to $5,000{\mu}g/plate$. GS95 did not induce chromosome aberration in Chinese hamster lung fibroblast in the concentration range between 1.25 and 5 mg/mL. In the rodent micronucleus assay, the frequency of micronucleated polychromatic erythrocyte in GS95 treated mice were not increased up to 5,000 mg/kg compared to the vehicle treated mice. Taken all these data together, GS95 was proven to be nongenotoxic in the concentration ranges tested.

Genotoxicity Studies on Corn Silk Extract Containing High Maysin (고메이신 함유 옥수수수염 추출물의 유전독성학적 안전성 연구)

  • Ha, Ae Wha;Kang, Hyeon Jung;Kim, Sun Lim;Kim, Myung Hwan;Kim, Woo Kyoung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.9
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    • pp.1045-1052
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    • 2017
  • In this study, a battery of genetic-toxicity studies on corn silk extract with high maysin content were performed according to internationally accepted protocols. In a mutation test using Salmonella Typhimurium TA1535, TA1537, TA98, and TA100, the number of mutant colonies did not significantly increase up to a maximum concentration of $5,000{\mu}g/plate$ in the presence or absence of the S9 metabolic activation system. In the chromosome aberration test using Chinese hamster lung fibroblasts, negative results were observed in the concentration up to $1,250{\mu}g/mL$ of corn silk extract. In the micronucleus test using ICR mice, incidence of polymorphonuclear erythrocytes with a maximum concentration of 2,000 mg/kg corn silk extract did not show any significant difference compared to the negative control group. Based on these results, the test substance, con silk extract, did not influence genotoxicity.