• 제목/요약/키워드: DNA loop

검색결과 182건 처리시간 0.022초

Detection of Salmonella typhi by Loop-mediated Isothermal Amplification Assay

  • 조윤경
    • 대한의생명과학회지
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    • 제14권2호
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    • pp.115-118
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    • 2008
  • Salmonella typhi is frequent causes of foodborne illness and its detection is important for monitoring disease progression. In this study, by using general PCR and novel LAMP (Loop Mediated Isothermal Amplification) assay, we evaluated the usefulness of LAMP assay for detection of Salmonella typhi. In this LAMP assay, forward inner primer (FIP) and back inner primer (BIP) was specially designed for recognizing target invA gene. Target DNA was amplified and visualized as ladder-like pattern of bands on agarose gel within 60 min under isothermal conditions at $65^{\circ}C$. When the sensitivity and reproducibility of LAMP were compared to general PCR, there was no difference of reproducibility but sensitivity of LAMP assay was more efficient than PCR (the detection limit of LAMP assay was 30 fg, while the PCR assay was 3 pg). These results indicate that the LAMP assay is a potential and valuable means for detection of Salmonella typhi, especially for its rapidity, simplicity and low cost.

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Development of Diagnostic Technology of Xylella fastidiosa Using Loop-Mediated Isothermal Amplification and PCR Methods

  • Kim, Suyoung;Park, Yujin;Kim, Gidon
    • 식물병연구
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    • 제27권1호
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    • pp.38-44
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    • 2021
  • Xylella fastidiosa is the most damaging pathogen in many parts of the world. To increase diagnostic capability of X. fastidiosa in the field, the loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR) assay were developed to mqsA gene of citrate-synthase (XF 1535) X. fastidiosa and evaluated for specificity and sensitivity. Both assays were more robust than current published tests for detection of X. fastidiosa when screened against 16 isolates representing the four major subgroups of the bacterium from a range of host species. No cross reaction with DNA from healthy hosts or other species of bacteria has been observed. The LAMP and PCR assays could detect 10-4 pmol and 100 copies of the gene, respectively. Hydroxynaphthol blue was evaluated as an endpoint detection method for LAMP. There was a significant color shift that signaled the existence of the bacterium when at least 100 copies of the target template were present.

Bovine Embryo Sexing by Loop-Mediated Isothermal Amplification (LAMP

  • Kojiya, S.;Watanabe, K.
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.183-183
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    • 2004
  • In the bovine embryo transfer industry, sexing preimplantation embryos is an important management tool. Several methods for bovine embryo sexing utilizing polymerase chain reaction (PCR) have been developed. However, they were not popularized because the methods requiretechnical skills and expensive instruments, and are time consuming. PCR also has the risk of false positives due to DNA contamination during the electrophoresis. (omitted)

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The Third Intracellular Loop of truman ${\beta}_2$-adrenergic Receptor Expressed in E. coli Decreased Binding Affinity of Isoproterenol to ${\beta}_2$-adrenergic Receptor

  • Shin, Jin-Chul;Shin, Chan-Young;Lee, Mi-Ok;Lee, Sang-Bong;Ko, Kwang-Ho
    • Biomolecules & Therapeutics
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    • 제4권1호
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    • pp.103-109
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    • 1996
  • To investigate the effect of the third intracellular loop (i3 loop) peptide of human $\beta$$_2$-adrenergic receptor on receptor agonist binding, we expressed third intracellular loop region of human $\beta$$_2$-adrenergic receptor as glutathione S-transferase fusion protein in E. coli. DNA fragment of the receptor gene which encodes amino acid 221-274 of human $\beta$$_2$-adrenergic receptor was amplified by polymerase chain reaction and subcloned into the bacterial fusion protein expression vector pGEX-CS and expressed as a form of glutathione-S-transferase (GST) fusion protein in E. coli DH5$\alpha$. The receptor fusion protein was identified by SDS-PAGE and Western blot using monoclonal anti-GST antibody. The fusion protein expressed in this study was purified to an apparent homogeneity by glutathione Sepharose CL-4B affinity chromatography. The purified i3 loop fusion proteins at a concentration of 10 $\mu\textrm{g}$/ι caused right shift of the isoproterenol competition curve of [$^3$H]Dihydroalprenolol binding to hamster lung $\beta$$_2$-adrenergic receptor indicating lowered affinity of isoproterenol to $\beta$$_2$-adrenergic receptor possibly due to the uncoupling of receptor and G protein in the presence of the fusion protein. The uncoupling of receptor and G protein suggests that i3 loop region plays a critical role on $\beta$$_2$-adrenergic receptor G protein coupling.

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멸구과 8종의 ITS2 DNA 염기서열 비교 분석과 고리매개등온증폭법(LAMP)을 이용한 벼멸구 특이 진단법 (ITS2 DNA Sequence Analysis for Eight Species of Delphacid Planthoppers and a Loop-mediated Isothermal Amplification Method for the Brown Planthopper-specific Detection)

  • 서보윤;박창규;고영호;정진교;조점래;강찬영
    • 한국응용곤충학회지
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    • 제56권4호
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    • pp.377-385
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    • 2017
  • 멸구과(Delphacidae) 8종의 internal transcribed spacer 2 (ITS2) DNA 염기서열로 종간 차이 추정값을 비교하고 분자계통수를 추론하였다. ITS2 DNA 염기서열 길이는 종(species)마다 550 bp (흰등멸구)에서 699 bp (겨풀멸구)까지 차이를 보였다. 같은 Nilaparvata 속의 겨풀멸구와 벼멸구붙이 사이의 염기서열 차이 추정값($d{\pm}S.E.$)은 $0.001{\pm}0.001$로 가장 낮았으며, 사슴멸구와 일본멸구 사이는 $0.579{\pm}0.021$로 가장 높았다. 벼멸구와 다른 멸구류들과의 종간 염기서열 차이 추정값은 $0.056{\pm}0.008$ (겨풀멸구)에서부터 $0.548{\pm}0.021$ (일본멸구)로 구분되었다. 반면, Neighbor-joining 방법으로 추론된 분자계통수에서는 겨풀멸구와 벼멸구붙이를 제외하고 나머지 멸구류들은 독립된 다른 그룹으로 분지되었다. 벼멸구의 ITS2 염기서열을 참고하여 벼멸구 특이 고리매개등온증폭(loop-mediated isothermal amplification, LAMP) 프라이머 4 세트(BPH-38, BPH-38-1, BPH-207 및 BPH-92)를 제작하였다. 이들 각각을 벼멸구, 흰등멸구 및 애멸구의 게놈 DNA와 $65^{\circ}C$에서 60분간 반응시켰을 때, 벼멸구 시료에서만 증폭 산물들이 관찰되었다. BPH-92 LAMP 프라이머 세트로 $65^{\circ}C$에서 벼멸구 DNA의 양(0.1 ng, 1 ng, 10 ng, 100 ng)과 반응시간(20분, 30분, 40분, 60분)을 달리하여 형광반응을 관찰하였을 때, 20분과 30분 반응에서는 100 ng 까지에서도 발광여부 구별이 어려웠다. 그러나 40분 반응에서는 10 ng 이상에서, 60분 반응에서는 0.1 ng 이상에서 발광여부가 명확히 구별되었다.

Coregulation of lux Genes and Riboflavin Genes in Bioluminescent Bacteria of Photobacterium phosphoreum

  • Sung, Nack-Do;Lee, ChanYong
    • Journal of Microbiology
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    • 제42권3호
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    • pp.194-199
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    • 2004
  • Investigation of the expression of the riboflavin (rib) genes, which are found immediately downstream of luxG in the lux operon in Photobacterium phosphoreum, provides more information relevant to the evolution of bioluminescence, as well as to the regulation of supply of flavin substrate for bacterial bioluminescence reactions. In order to answer the question of whether or not the transcriptions of lux and rib genes are integrated, a transcriptional termination assay was performed with P. phoxphoreum DNA, containing the possible stem-loop structures, located in the intergenic region of luxF and luxE ($\Omega$$\_$A/), of luxG and ribE ($\Omega$$\_$B/), and downstream of ribA ($\Omega$$\_$c/). The expression of the CAT (Chloram-phenicol Acetyl Transferase) reporter gene was remarkably decreased upon the insertion of the stem-loop structure ($\Omega$$\_$c/) into the strong lux promoter and the reporter gene. However, the insertion of the structure ($\Omega$$\_$B/) into the intergenic region of the lux and the rib genes caused no significant change in expression from the CAT gene. In addition, the single stranded DNA in the same region was protected by the P. phosphoreum mRNA from the Sl nuclease protection assay. These results suggest that lux genes and rib genes are part of the same operon in P. phosphoreum.

Genetic Variation and Phylogenetic Relationships of Indian Buffaloes of Uttar Pradesh

  • Joshi, Jyoti;Salar, R.K.;Banerjee, Priyanka;Upasna, S.;Tantia, M.S.;Vijh, R.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제26권9호
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    • pp.1229-1236
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    • 2013
  • India possesses a total buffalo population of 105 million out of which 26.1% inhabit Uttar Pradesh. The buffalo of Uttar Pradesh are described as nondescript or local buffaloes. Currently, there is no report about the genetic diversity, phylogenetic relationship and matrilineal genetic structure of these buffaloes. To determine the origin and genetic diversity of UP buffaloes, we sequenced and analysed the mitochondrial DNA D-loop sequences in 259 samples from entire Uttar Pradesh. One hundred nine haplotypes were identified in UP buffaloes that were defined by 96 polymorphic sites. We implemented neutrality tests to assess signatures of recent historical demographic events like Tajima's D test and Fu's Fs test. The phylogenetic studies revealed that there was no geographic differentiation and UP buffaloes had a single maternal lineage while buffaloes of Eastern UP were distinctive from rest of the UP buffaloes.

Mitochondrial DNA Variation and Genetic Relationships in Japanese and Korean Cattle

  • Sasazaki, S.;Odahara, S.;Hiura, C.;Mukai, F.;Mannen, H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권10호
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    • pp.1394-1398
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    • 2006
  • The complete mtDNA D-loop regions of Japanese and Korean cattle were analyzed for their mtDNA variations and genetic relationships. Sequencing the 30 Higo substrain and 30 Tosa substrain of Japanese Brown, respectively 12 and 17 distinct Bos haplotypes were identified from 77 polymorphic nucleotide sites. In order to focus on the relationships among Japanese and Korean cattle, two types of phylogenetic tree were constructed using individual sequences; first, a neighbor-joining tree with all sequences and second, reduced median networks within each Japanese and Korean cattle group. The trees revealed that two major mtDNA haplotype groups, T3 and T4, were represented in Japanese and Korean cattle. The T4 haplogroup predominated in Japanese Black and Japanese Brown cattle (frequency of 43.3-66.7%), while the T3 haplogroup was predominant (83.3%) and T4 was represented only twice in the Korean cattle. The results suggested that the mitochondrial origins of Japanese Brown were Japanese ancient cattle as well as Japanese Black in despite of the considerable introgression of Korean and European cattle into Japanese Brown.

Recyclable single-stranded DNA template for synthesis of siRNAs

  • Ali, Mussa M.;Obregon, Demian;Agrawal, Krishna C.;Mansour, Mahmoud;Abdel-Mageed, Asim B.
    • BMB Reports
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    • 제43권11호
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    • pp.732-737
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    • 2010
  • RNA interference is a post-transcriptional silencing mechanism triggered by the bioavailability and/or exogenous introduction of double-stranded RNA (dsRNA) into cells. Here we describe a novel method for the synthesis of siRNA in a single vessel. The method employs in vitro transcription and a single-stranded DNA (ssDNA) template and design, which incorporates upon self-annealing, two promoters, two templates, and three loop regions. Using this method of synthesis we generated efficacious siRNAs designed to silence both exogenous and endogenous genes in mammalian cells. Due to its unique design the single-stranded template is easily amenable to adaptation for attachment to surface platforms for synthesis of siRNAs. A siRNA synthesis platform was generated using a 3' end-biotinylated ssDNA template tethered to a streptavidin coated surface that generates stable siRNAs under multiple cycles of production. Together these data demonstrate a unique and robust method for scalable siRNA synthesis with potential application in RNAi-based array systems.