• Title/Summary/Keyword: Gene Screening

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Anti-staphylococcal Bacteriocin from Enterococcus faecium

  • Kim, Kyung-Suk;Lee, Ung-Soo;Moon, Gi-Seong
    • Preventive Nutrition and Food Science
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    • v.15 no.1
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    • pp.74-77
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    • 2010
  • Antibiotic-resistant Staphylococcus aureus is beginning to pose a social issue. Thus, there is an urgent need for the development of effective anti-staphylococcal agents to eradicate antibiotic-resistant S. aureus in food systems and to treat the pathogen in clinical areas. To address this need, lactic acid bacteria (LAB) from kimchi were screened for the production of anti-staphylococcal bacteriocin. From this screening, a bacteriocin generated by the MK3 strain, which was identified by 16S rRNA gene sequence analysis as Enterococcus faecium, demonstrated antimicrobial activity against an S. aureus strain, and was designated enterocin MK3. Enterocin MK3 also demonstrated activity against other gram-positive bacteria, including several LAB and Listeria monocytogenes, but not gram-negative Escherichia coli. The molecular mass of enterocin MK3 was estimated as approximately 6.5 kDa on an SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) gel.

Identification of a Pathogen-Induced Glycine max Transcription Factor GmWRKY1

  • Kang, Sang-Gu;Park, Eui-Ho;Do, Kum-Sook
    • The Plant Pathology Journal
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    • v.25 no.4
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    • pp.381-388
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    • 2009
  • On screening pathogen-resistant soybean, we identified a WRKY type transcription factor named a Glycine max WRKY1 (GmWRKY1). Expression of GmWRKY1 gene was induced in the soybean sprout by Pseudomonas infection. The GmWRKY1 was expressed in all of the tissues with high levels in stems, leaves and developing seeds. The protein Gm WRKY1 contains highly conserved two WRKY DNA-binding domains having two $C_2-H_2$ zinc-finger motif ($C-X_{4-5}-C-X_{22-23}-H-X-H$) in its N-terminal and C-terminal amino acid sequences. In electrophoresis mobility shift assay, the GmWRKY1 protein bound specifically to W-box elements in the promoters of defense related genes. These results demonstrated that GmWRKY1 is one of the soybean WRKY family genes and the plant-specific transcription factors for defense processes.

Cell- and Stage-Specific Expression of the Murine nm23-M5 Gene during Late Spermatogenesis and Spermiogenesis

  • Hwang Gyu-Chan;Ok Do-Won;Lee Mi-Suk;Kim Jin-Hoe
    • Proceedings of the KSAR Conference
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    • 2002.06a
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    • pp.5-5
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    • 2002
  • Nucleoside diphosphate kinases (NDPKs) are conserved through evolution and have been shown to be involved in various biological phenomena. By functional screening in yeast, we identified a new member of the NDPK family, ㎚23-M5, which encodes a 211-amino acid protein with 86% identify to the human homolog, ㎚23-H5. Northern blot analysis reveals that ㎚23-M5 encodes two transcripts of 0.8 and 0.7 kb, which are highly and specifically expressed in adult testis. Reverse transcriptase polymerase chain reaction analysis shows that nm23-M5 first appears in pachytene spermatocytes and increase chain reaction in abundance through subsequent stages. (omitted)

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STABLE TRANSFORMATION OF CULTURED CHICKEN CELLS

  • Han, J.Y.;Shin, Y.S.;Shoffner, R.N.;Guise, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.6 no.4
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    • pp.581-589
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    • 1993
  • A plasmid vector, $RSVLTR/{\beta}G2$, containing lacZ gene under the control of the RSVLTR promoter were transfected into chicken embryo fibroblasts by three different transfection methods. Calcium phosphate, lipsome and DEAE-dextran techniques were applied for transfection of chicken cells. A histochemical assay with X-gal was used as a simple method for screening transfected cells. Plasmid $RSVLTR/{\beta}G2$ was expressed proficiently in the chicken embryo fibroblast. Calcium phosphate-DNA precipitate transfection resulted in the highest efficiency for transient expression of $RSVLTR/{\beta}G2$. Transfected cells formed colonies on the 9th day of incubation indicating stable transformation of the inserted plasmid.

Identification of 2-Deoxy-scyllo-inosose Synthase in Aminoglycoside Producer Streptomyces

  • Kharel, Madan-Kumar;Subba, Bimala;Lee, Hei-Chan;Liou, Kwang-Kyoung;Woo, Jin-Suk;Kim, Dong-Hwan;Moon, Young-Ho;Sohng, Jae-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.13 no.5
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    • pp.828-831
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    • 2003
  • Although most of the DOS containing aminoglycosides are produced by Streptomyces, very little information is available about their biosynthesis. In the present paper, we report a method to isolate DOI synthase, a key enzyme in the biosynthesis of DOS, from aminoglycoside producer Streptomyces. PCR primers based on conserved region of DOI synthases were specific and reliable for the isolation of the biosynthetic genes of DOS containing aminoglycosides or the screening of the aminoglycoside producers. The use of DOI synthase as a probe could save both time and cost of cloning aminoglycoside biosynthetic genes.

Screening of RAPD Markers for Fluoride Resistance in Bombyx mori L.

  • Chen, Keping;Yao, Qin;Li, Muwang;Wang, ong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.1
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    • pp.11-14
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    • 2003
  • NF733xin, the near allele line was obtained by means of crossing and backcrossing the silkworm race T6, which contained fluoride resistance major gene, to race 733xin, which was highly susceptible to fluoride toxicity. Two hundred RAPD random primers were used in the RAPD analysis of these 3 strains. Two molecular markers, OPB-08850 and OPB-10917, were obtained. OPB-10917 was used to detect the backcross generations. It was found that all the fluoride resistant individuals in each backcross generation had the same special band. These results proved that this marker was reliable.

On a highly proteolytic mutant strain of Aspergillus flavus (Aspergillus flavus의 강력 protease생성 돌연변이의 유발)

  • 이영녹;박용근;고상균
    • Korean Journal of Microbiology
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    • v.18 no.2
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    • pp.51-58
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    • 1980
  • Mutational experiments were performed to improved to improve the protease productivity of Aspergillus flavus KU 153, which is selected among the wild strains. A UV-induced mutant strain having high protease productivity was obtained by the use of the clear zone method as a simple criterion for a primary screening test. Neutral and alkaline protease activities of hte mutant strain were higher than 1.8 times, comopared with those of the parental strain, respectively, while in the case of acid protease, it was 2.7 times. The mutant strain selected was more powerful in the production of cellulase and amylase, as well s protease in wheat bran, compared with those of the parental strain. protease production of the parental strain has reached maximum level at 3 days culture, while alkaline nad neutral protease production of the mutantstrain has reached at 2 days culture. On the other hand, the mutant strain formed the spore slowly, compared with the parental strain. Column chromatography of the neutral protease on DEAE-Sephadex A-50 showed that the mutant strain was not induced the formation of another neutral protease isozyme, but induced the variation in the function of regulatory gene.

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siMacro: A Fast and Easy Data Processing Tool for Cell-Based Genomewide siRNA Screens

  • Singh, Nitin Kumar;Seo, Bo Yeun;Vidyasagar, Mathukumalli;White, Michael A.;Kim, Hyun Seok
    • Genomics & Informatics
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    • v.11 no.1
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    • pp.55-57
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    • 2013
  • Growing numbers of studies employ cell line-based systematic short interfering RNA (siRNA) screens to study gene functions and to identify drug targets. As multiple sources of variations that are unique to siRNA screens exist, there is a growing demand for a computational tool that generates normalized values and standardized scores. However, only a few tools have been available so far with limited usability. Here, we present siMacro, a fast and easy-to-use Microsoft Office Excel-based tool with a graphic user interface, designed to process single-condition or two-condition synthetic screen datasets. siMacro normalizes position and batch effects, censors outlier samples, and calculates Z-scores and robust Z-scores, with a spreadsheet output of >120,000 samples in under 1 minute.

Screening of Promoter Sequences from Lactic Acid Bacteria Using a Promoter-Selection Vector (Promoter-Selection Vector를 사용한 유산균 Promoter의 탐색)

  • 우승희;김갑석
    • KSBB Journal
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    • v.11 no.4
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    • pp.504-509
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    • 1996
  • Promoters which are useful for constructing expression vectors for lactic acid bacteria were obtained from the chromosomal DNA of Lactococcus lactis ssp. lactis MG1363. pBV5030, a promoter-selection vector, replicates in L. lactis and Escherichia coli and carries a promoterless chloramphenicol acetyltransferase gene (cat-86). After examining E. coli transformants which grew on LB media containing chloramphenicol (Cm, 20$\mu\textrm{g}$/mL) , many MG1363 derived DNA fragments which encompass promoter sequences were identified. Some recombinant E. coli cells can grow at the Cm concentration of 1,000$\mu\textrm{g}$/mL. When plasmids from those highly resistant E. coli cells were purified and introduced into L. lactis ssp. lactis MG1614 cells by electroporation, lactococcal transformants showing Cm resistance were obtained. So far, five plasmids with different promoter inserts were introduced into L. lactis MGl614 cells. The maximum level of Cm resistance in L. lactis MG1614 transformants was quite low (20$\mu\textrm{g}$/mL) when compared with that observed in recombinant E. coli cells harboring the same plasmids.

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The AP-3 Clathrin-associated Complex Is Essential for Embryonic and Larval Development in Caenorhabditis elegans

  • Shim, Jaegal;Lee, Junho
    • Molecules and Cells
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    • v.19 no.3
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    • pp.452-457
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    • 2005
  • The adaptor protein (AP) complexes are involved in membrane transport of many proteins. There are 3 AP complexes in C. elegans unlike mammals that have four. To study the biological functions of the AP-3 complexes of C. elegans, we sought homologues of the mouse and human genes that encode subunits of the AP-3 complexes by screening C. elegans genomic and EST sequences. We identified single copies of homologues of the ${\mu}3$, ${\sigma}3$, ${\beta}3$ and ${\delta}$ genes. The medium chain of AP-3 is encoded by a single gene in C. elegans but two different genes in mammals. Since there are no known mutations in these genes in C. elegans, we performed RNAi to assess their functions in development. RNAi of each of the genes caused embryonic and larval lethal phenotypes. APM-3 is expressed in most cells, particularly strongly in spermatheca and vulva. We conclude that the products of the C. elegans ${\mu}3$, ${\sigma}3$, ${\beta}3$ and d genes are essential for embryogenesis and larval development.