• Title/Summary/Keyword: environmental DNA

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Megabase-sized DNA isolation and electrophoretic karyotype of fusarium oxysporum schlecht

  • Park, Min-Seon;Min, Byung-Re
    • Journal of Microbiology
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    • v.33 no.2
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    • pp.132-135
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    • 1995
  • To investigate the electrophoretic karytype of Fusarium oxysporum, intact chromosomal DNA was separated by pulsed-field gel electrophoresis (PEGE). DNA extraction from nulcei, mycelia and protoplasts were compared with one another and with the quantity and the suitability for PFGE separation in agarose gel. As a result, the most useful extracting method for intact DNA was found to be that from protoplasts. By varying the electrophoretic conditions, 8 chromosomal DNA bounds were resolved. Using the Schizosaccharomyces pombe and Saccharomyces cerevisiae as size standards, the size of Fusarium oxysporum chromosomes was estimated to range from approximately 0.6 Mb TO 6.7 Mb, and total genome size was 26.7 Mb. The suitability of electrophoretic karyotyping as a tool for strain characterization is discussed.

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Protective Effects of Chitosan on the Cadmium Cytotoxicity in Rat Glioma Cells (흰쥐 신경교종세포에서 카드뮴 세포독성에 대한 키토산의 효과)

  • 백용아;이정래;김강득;김혜원;이한솔;허정무;오재민;최민규;정연태
    • Toxicological Research
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    • v.20 no.1
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    • pp.63-69
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    • 2004
  • Casapse-3 protease is known as a key role of apoptotic enzyme, and caspase-3 activity is a central event that occurs upstream of DNA fragmentation during apoptosis. This study demonstrates that chitosan pretreatment inhibits cadmium-induced apoptosis by attenuating the activity of caspase-3. We also analyzed the protective effect of chitosan on DNA fragmentation induced by cadmium. Cadmium toxicity was examined by DNA fragmentation and nuclear condensation with Hoechst stain. Caspase-3 activities were increased cadmium treated group for 3 hours compared with control. When chitosan (150 mg/ml) was pretreated at 30 min before cadmium treatment, cadmium cytotoxicity was suppressed in a dose-dependent manner evaluated by DNA fragmentation and caspase activity. From these results, it is suggest that the protective effect of chitosan pretreatment against cadmium-induced cytotoxicity is mediated through inhibition of caspase-3 protease activation and DNA fragmentation.

A Partial Nucleotide Sequence of Chitin Synthase (CHS) Gene from Rice Blast Fungus, Pyricularia oryzae and Its Cloning

  • Hwang, Cher-Won;Park, In-Cheol;Yeh, Wan-Hae;Takagi, Masamchi;Ryu, Jin-Chang
    • Journal of Microbiology and Biotechnology
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    • v.7 no.2
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    • pp.157-159
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    • 1997
  • A 340-bp chitin synthase gene(CHS) fragment was cloned from the genomic DNA of Pyricularia oryzae using a PCR process with two primer DNAs corresponding to highly conserved sequences within fungal CHS genes. The entire DNA nucleotide sequences of the cloned DNA fragment were determined and analyzed. The amino acid sequences deduced from the nucleotide sequence of the amplified DNA fragment showed 86% homology to that of the Aspergillus fumigatus CHSE gene (9). Using this PCR-amplified DNA, about 2.3 kb of including the PCR fragment of CHSE gene was cloned from genomic library.

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Molecular Genetic Mechanism of Aromatic Compound Biodegradation by soil Streptomycetes

  • Kim, Eumg-Soo
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2001.06a
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    • pp.118-119
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    • 2001
  • A Southern-hybridization analysis and size-selected DNA library screening led to the isolation of a 6.3-kbp S. setonii DNA fragment, from which the Cl20-encoding genetic locus was found to be located within a 1.4-kbp DNA fragment. A complete nucleotide sequencing analysis of the 1.4-kbp DNA fragment revealed a 0.84-kbp ORF, which showed a strong overall amino acid similarity to the known high-G+C gram-positive bacterial mesophilic C120s. The heterologous expression of the cloned 1.4-kbp DNA fragment in E. coli demonstrated that this Cl20 possessed a thermophilic activity within a broad temperature range and showed a higher activity against 3-methy1catechol than catechol or 4-methy-catechol, but no activity against protocatecuate.

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DNA, RNA, Protein and Yield of the Soybean Plant, Glycine max Merr., as Affected by Phosphorus Nutrition (대두의 핵산, 단백질 및 물질생산에 미치는 인산비료의 효과)

  • 장남기
    • Journal of Plant Biology
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    • v.16 no.1_2
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    • pp.23-29
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    • 1973
  • The effect of phosphorus nutrition on the content of deoxyribonucleic acid(DNA), ribonucleic acid(RNA), crude protein and plant growth of soybean plant(Glycine max, Merr.) was studied. Yields of the above-and under-ground parts of the soybean plant in terms of dry weight, the amounts of crude protein, RNA and DNA continued to increase with increasing phosphorus supply. The amounts of RNA and crude protein were highest in the leaf tissues where most intensive growth was taking place. The relationships among DNA, RNA, crude protein and plant growth appeared to consist of the central dogma which has immortalized, while DNA in plant tissue was subject to charges cuased by external environmental facters such as phosphorus nutrition.

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cDNA Cloning and Stage-Dependant Expression of Arylphorin Gene from Chinese Oak Silkworm, Antheraea pernyi (작잠(Antheraea pernyi) 아릴포린(Arylphorin) 유전자의 cDNA 클로닝 및 아릴포린 유전자의 발육시기 의존성 발현양상)

  • Lee, Sang-Mong;Hwang, Jae-Sam;Park, Nam-Sook;Kim, Yong-Gyun;Kim, Keun-Ki;Son, Hong-Joo;Park, Hyun-Chul;Jin, Byung-Rae
    • Journal of Life Science
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    • v.20 no.8
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    • pp.1193-1200
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    • 2010
  • The cDNA cloning and developmental profiles of the mRNA for A. pernyi arylphorin was determined. The complete A. pernyi arylphorin cDNA sequence comprised 2,234 bp (without the poly $A^+$ tail), including an open reading frame of 2,112 bp beginning with a methionine ATG at bp34. The A. pernyi arylphorin contained 704 amino acids which are highly enriched in aromatic amino acids, phenylalanine and tyrosine. The calculated molecular mass of the A. pernyi arylphorin from the ORF was 83,439 Da. The deduced amino acid sequence of A. pernyi arylphorin showed 78, 71, 62 and 64% identity with those of H. cecropia, M. sexta $\alpha$ subunit, M. sexta $\beta$ subunit and B. mori storage protein. In Northern blot analysis, the A. pernyi arylphorin mRNA only in the fat body of the 5th instar larvae was responsible for gene expression of the protein, and the synthetic activity of the mRNA was detected strongly in the early larvae, but not in the middle or late-stage larvae. In addition, a very weak signal in mRNA activity was detected in pupal stages, but this was considered to be inactive mRNA after reviewing the results of the labeling experiment of this protein.

A Critical Evaluation of DNA Adducts as Biological Markers for Human Exposure to Polycyclic Aromatic Compounds

  • Godschalk, Roger W.L.;Van Schooten, Frederik-Jan;Bartsch, Helmut
    • BMB Reports
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    • v.36 no.1
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    • pp.1-11
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    • 2003
  • The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention of chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria:i.adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined.iii. sources of inter- and intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAH-exposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with non-exposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intra-individual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurement may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. Biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurement as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.