• Title/Summary/Keyword: Gene Screening

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A Rapid Procedure for Screening and Isolation of Various Sizes of Plasmid DNA in Serovars of Bacillus thuringiensis (Bacillus turingiensis 변종(變種)들로부터의 Plasmid DNA 추출(抽出) 및 분리(分離))

  • LEE, YUNG KEUN;Faust, Robert M.;KANG, SEOK KWON;McCawley, Patricia E.;Meyers-Dowling, Carol L.
    • Korean journal of applied entomology
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    • v.24 no.1 s.62
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    • pp.45-50
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    • 1985
  • The use of a modified procedure for the isolation of extrachromosomal DNA of low to high molecular weight, followed by agarose gel electrophoresis of the crude lysates, provided a simple screening procedure for detecting plasmids ranging in molecular weights from approximately 1 to more than 135 megadaltons from serovars of Bacillus thuringiensis. The procedure provides for a relatively large-volume stable lysate for isolation of plasmids for restriction endonuclease mapping and cloning procedures. The method was used for screening of plasm ids in 6 differenentially effective serovars of B. thuringiensis toxic to dipteran and lepidopteran insects. Relatively large plasmid DNAs of masses above 50 megadaltons (Mdal) were isolated from all of the serovars examined using this technique. The number of extrachromosomal DNAs detected in serovars of B. thuringiensis was 8 for israelensis, 10 for kurstaki, 13 for aizawai, 2 for dendrolimus, 1 for finitimus, and 6 for yunnanensis. Smaller plasmid DNAs were isolated in four of the six serovars that ranged in mass down to approximately 2 Mdal.

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Comparision of PCR-RFLP, PCR-SSCP, Amplication Refractory Mutation System(ARMS) in Leu72Met Polymorphism of Ghrelin Gene (Ghrelin 유전자의 Leu72Met 다형성 분석에서 PCR-RFLP, PCR-SSCP, Amplication Refractory Mutation System(ARMS)의 비교분석)

  • Kang, Ju Sung;Kim, Se Rim;Kim, Sun Young;Joo, Chan Uhng;Cho, Soo Chul;Hwang, Pyoung Han
    • Clinical and Experimental Pediatrics
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    • v.48 no.10
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    • pp.1068-1075
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    • 2005
  • Purpose : The role of ghrelin, which promotes the secretion of growth hormone, was not well known until now. Recently it was found that the mutation of ghrelin gene is related to obesity and diabetes. This study is to find the screening method that can easily and effectively detect the polymorphism of Leu72Met in ghrelin gene of obesity patients and apply it to clinical usage. Methods : We compared PCR-RFLP, PCR-SSCP and ARMS methodologies for analyzing of the polymorphism of Leu72Met in ghrelin gene of obesity children, and also studied the merits and demerits of these methodologies. Results : In this study, we were able to find out the band of peculiar allele of Leu72Met in ghrelin gene using PCR-RFLP, PCR-SSCP and ARMS analyses. The polymorphism of Leu72Met in ghrelin gene determined by all above methodologies was in complete agreement. Compared to the PCR-RFLP and PCR-SSCP, ARMS analysis is simple, inexpensive and also consume less time. It is very sensitive to analyze the polymorphism and easy to understand the results of test. Conclusion : Though PCR-RFLP, PCR-SSCP and ARMS analyses were sensitive to analyze the polymorphism of Leu72Met in ghrelin gene, ARMS analysis appears to be more efficient than PCR-RFLP and PCR-SSCP. Therefore, we conclude that ARMS analysis is suitable to analyze the polymorphism of Leu72Met in ghrelin gene for large quantity of specimens.

Characterization and Cloning of the Gene Encoding Autoregulator Receptor Protein from Streptomyces longwoodensis (Streptomyces longwoodensis로부터 Autoregulator Receptor Protein 유전자의 클로닝 및 특성)

  • Yeo Soo-Hwan;Lee Sung-Bong;Kim Hyun-Soo
    • Microbiology and Biotechnology Letters
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    • v.33 no.2
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    • pp.96-105
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    • 2005
  • For screening of autoregulator receptor gene from Streptomyces longwoodensis, PCR was performed with primers of receptor gene designed on the basis of amino acid sequences of autoregulator receptor proteins with known function. PCR products were subcloned into the BamHIsite of pUC19 and transformed into the E. coli $DH5{\alpha}$. The isolated plasmid from transformant contained the fragment of 100 bp, which was detected on $2\%$ gel after BamHI treatment. The insert, 100 bp PCR product, was confirmed as the expected internal segment of gene encoding autoregulator receptor protein by sequencing. Southern and colony hybridizations with the 100 bp fragment as a probe allowed to select a genomic clone of S. longwoodensis, pSLT harboring a 4.4 kb SphI fragment. Nucleotide sequencing analyses revealed a 651 bp open reading frame(ORF) were isolated protein showing moderate homology ($35{\sim}46\%$) with the ${\Gamma}$-butyrolactone autoregulator receptors from Streptomyces sp., and this ORF was named sltR The sltR/pET-17b plasmid was constructed to overexpress the recombinant SltR protein (rSltR) in E. coli BL21 (DE3)/pLysS, and the rSltR protein was purified to homogeneity by DEAE-Sephacel column chromatography, and DEAE-5PW chromatography (HPLC). The molecular mass of the purified rSltR protein was 55 kDa by HPLC gel-filtration chromatography and 28 kDa by SDS-PAGE, indicating that the rSltR protein is present as a dimer. A binding assay with tritium-labeled autoregulators revealed that the rSltR has clear binding activity with a A-factor type autoregulator as the most effective ligand.

Chimeric RNAs as potential biomarkers for tumor diagnosis

  • Zhou, Jianhua;Liao, Joshua;Zheng, Xuexiu;Shen, Haihong
    • BMB Reports
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    • v.45 no.3
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    • pp.133-140
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    • 2012
  • Cancers claim millions of lives each year. Early detection that can enable a higher chance of cure is of paramount importance to cancer patients. However, diagnostic tools for many forms of tumors have been lacking. Over the last few years, studies of chimeric RNAs as biomarkers have emerged. Numerous reports using bioinformatics and screening methodologies have described more than 30,000 expressed sequence tags (EST) or cDNA sequences as putative chimeric RNAs. While cancer cells have been well known to contain fusion genes derived from chromosomal translocations, rearrangements or deletions, recent studies suggest that trans-splicing in cells may be another source of chimeric RNA production. Unlike cis-splicing, trans-splicing takes place between two pre-mRNA molecules, which are in most cases derived from two different genes, generating a chimeric non-co-linear RNA. It is possible that trans-splicing occurs in normal cells at high frequencies but the resulting chimeric RNAs exist only at low levels. However the levels of certain RNA chimeras may be elevated in cancers, leading to the formation of fusion genes. In light of the fact that chimeric RNAs have been shown to be overrepresented in various tumors, studies of the mechanisms that produce chimeric RNAs and identification of signature RNA chimeras as biomarkers present an opportunity for the development of diagnoses for early tumor detection.

Construction of a System for the Strawberry Nursery Production towards Elimination of Latent Infection of Anthracnose Fungi by a Combination of PCR and Microtube Hybridization

  • Furuta, Kazuyoshi;Nagashima, Saki;Inukai, Tsuyoshi;Masuta, Chikara
    • The Plant Pathology Journal
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    • v.33 no.1
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    • pp.80-86
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    • 2017
  • One of the major problems in strawberry production is difficulty in diagnosis of anthracnose caused by Colletotrichum acutatum or Glomerella cingulata in latent infection stage. We here developed a diagnostic tool for the latent infection consisting of initial culturing of fungi, DNA extraction, synthesis of PCR-amplified probes and microtube hybridization (MTH) using a macroarray. The initial culturing step is convenient to lure the fungi out of the plant tissues, and to extract PCR-inhibitor-free DNA directly from fungal hyphae. For specific detection of the fungi, PCR primers were designed to amplify the fungal MAT1-2 gene. The subsequent MTH step using the PCR products as probes can replace the laborious electrophoresis step providing us sequence information and high-throughput screening. Using this method, we have conducted a survey for a few thousands nursery plants every year for three consecutive years, and finally succeeded in eliminating latent infection in the third year of challenge.

Rapid and Sensitive Detection of Hepatitis C Virus in Clinical Blood Samples Using Reverse Transcriptase Polymerase Spiral Reaction

  • Sun, Wenying;Du, Ying;Li, Xingku;Du, Bo
    • Journal of Microbiology and Biotechnology
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    • v.30 no.3
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    • pp.459-468
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    • 2020
  • This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5'UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

Detection of the cell wall-affecting antibiotics at sublethal concentrations using a reporter Staphylococcus aureus harboring drp35 promoter - lacZ transcriptional fusion

  • Mondal, Rajkrishna;Chanda, Palas K.;Bandhu, Amitava;Jana, Biswanath;Lee, Chia-Y.;Sau, Subrata
    • BMB Reports
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    • v.43 no.7
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    • pp.468-473
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    • 2010
  • Previously, various inhibitors of cell wall synthesis induced the drp35 gene of Staphylococcus aureus efficiently. To determine whether drp35 could be exploited in antistaphylococcal drug discovery, we cloned the promoter of drp35 ($P_d$) and developed different biological assay systems using an engineered S. aureus strain that harbors a chromosomally-integrated $P_d$ - lacZ transcriptional fusion. An agarose-based assay showed that $P_d$ is induced not only by the cell wall-affecting antibiotics but also by rifampicin and ciprofloxacin. In contrast, a liquid medium-based assay revealed the induction of $P_d$ specifically by the cell wall-affecting antibiotics. Induction of $P_d$ by sublethal concentrations of cell wall-affecting antibiotics was even assessable in a microtiter plate assay format, indicating that this assay system could be potentially used for high-throughput screening of new cell wall-inhibiting compounds.

Screening Wild Yeast Strains for Alcohol Fermentation from Various Fruits

  • Lee, Yeon-Ju;Choi, Yu-Ri;Lee, So-Young;Park, Jong-Tae;Shim, Jae-Hoon;Park, Kwan-Hwa;Kim, Jung-Wan
    • Mycobiology
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    • v.39 no.1
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    • pp.33-39
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    • 2011
  • Wild yeasts on the surface of various fruits including grapes were surveyed to obtain yeast strains suitable for fermenting a novel wine with higher alcohol content and supplemented with rice starch. We considered selected characteristics, such as tolerance to alcohol and osmotic pressure, capability of utilizing maltose, and starch hydrolysis. Among 637 putative yeast isolates, 115 strains exhibiting better growth in yeast-peptone-dextrose broth containing 30% dextrose, 7% alcohol, or 2% maltose were selected, as well as five ${\alpha}$-amylase producers. Nucleotide sequence analysis of the 26S rDNA gene classified the strains into 13 species belonging to five genera; Pichia anomala was the most prevalent (41.7%), followed by Wickerhamomyces anomalus (19.2%), P. guilliermondii (15%), Candida spp. (5.8%), Kodamaea ohmeri (2.5%), and Metschnikowia spp. (2.5%). All of the ${\alpha}$-amylase producers were Aureobasidium pullulans. Only one isolate (NK28) was identified as Saccharomyces cerevisiae. NK28 had all of the desired properties for the purpose of this study, except ${\alpha}$-amylase production, and fermented alcohol better than commercial wine yeasts.

Automatic Reading System for On-off Type DNA Chip

  • Ryu, Mun-Ho;Kim, Jong-Dae;Kim, Jong-Won
    • Journal of Information Processing Systems
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    • v.2 no.3 s.4
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    • pp.189-193
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    • 2006
  • In this study we propose an automatic reading system for diagnostic DNA chips. We define a general specification for an automatic reading system and propose a possible implementation method. The proposed system performs the whole reading process automatically without any user intervention, covering image acquisition, image analysis, and report generation. We applied the system for the automatic report generation of a commercialized DNA chip for cervical cancer detection. The fluorescence image of the hybridization result was acquired with a $GenePix^{TM}$ scanner using its library running in HTML pages. The processing of the acquired image and the report generation were executed by a component object module programmed with Microsoft Visual C++ 6.0. To generate the report document, we made an HWP 2002 document template with marker strings that were supposed to be searched and replaced with the corresponding information such as patient information and diagnosis results. The proposed system generates the report document by reading the template and changing the marker strings with the resultant contents. The system is expected to facilitate the usage of a diagnostic DNA chip for mass screening by the automation of a conventional manual reading process, shortening its processing time, and quantifying the reading criteria.

Detection and genetic characteristic of Yellow-head virus genotype 8 (YHV-8) Cultured Litopanaeus vanamei, in Korea (국내 양식 흰다리새우에서 검출된 노랑머리바이러스(YHV-8)의 유전학적 특성)

  • Kim, Seok-Ryel;CWR, Gunasekara;SHMP, Wimalasena;Shin, Gee-Wook
    • Journal of fish pathology
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    • v.33 no.1
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    • pp.77-81
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    • 2020
  • This study was performed for screening yellow head virus(YHV) complex in 252 including 235 white leg shrimps (Litopenaeus vannamei) and 17 oriental shrimp (Fenneropenaeus chinensis) collected from 18 farms located in southwestern province of Korea. The virus complex was detected by nested reverse-transcriptase polymerase chain reaction (RT-PCR) assay. In the assay, amplicons were resulted in RNAs exracted from 38 shrimps (21 white leg shrimps and 17 oriental shrimps) obtained from 7 farms. In phylogenetic analysis using sequences of ORF1b gene, all 38 sequences obtained in this study formed an independent lineage with YHV-8 genotype firstly isolated in China, belonged to an YHV-8 clade.