• Molecules and Cells
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• v.27 no.1
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• pp.83-88
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• 2009

Amino acid homology analysis predicted that rbmD, a putative glycosyltransferase from Streptomyces ribosidificus ATCC 21294, has the highest homology with neoD in neomycin biosynthesis. S. fradiae BS1, in which the production of neomycin was abolished, was generated by disruption of the neoD gene in the neomycin producer S. fradiae. The restoration of neomycin by self complementation suggested that there was no polar effect in the mutant. In addition, S. fradiae BS6 was created with complementation by rbmD in S. fradiae BS1, and secondary metabolite analysis by ESI/MS, LC/MS and MS/MS showed the restoration of neomycin production in S. fradiae BS6. These gene inactivation and complementation studies suggested that, like neoD, rbmD functions as a 2-N-acetlyglucosaminyltransferase and demonstrated the potential for the generation of novel aminoglycoside antibiotics using glycosyltransferases in vivo.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.557-561
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• 1993

The neomycin phosphotransferase II gene (nptII) was introduced into geranium (Pelargonium zonale hybrids) protoplast by using PEG or electroporation method. The presence of the introduced DNA in the protoplast and the expressions of the gene in the transformed cells were examined. The presence of the nptII DNA in the protoplasts were detected by polymerase chain reaction. The expressions of nptII gene in the transformed cells were confirmed by the nptII assay.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.111-116
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• 1998

To construct transformed Bm5 cells, Autographa californica nuclear polyhedrosis virus (AcNPV)IE1 gene, an immediate early viral gene was firstly used in this study. AcNPV IE1 gene, which shares on 95.3% uncleotide sequence homology with Bombyx mori nuclear polyhedrosis virus (BmNPV) IE1 gene, was isolated and cloned into pBluescript. Neomycin gene from pKO-neo was inserted under the control of the IE1 promoter to yield pAcIE1-neo. The plasmid pAcIE1-neo was transfected into Bm5 or Sf9 cells, and neomycin-resistant cells were selected in TC100 medium containing 10% fetal bovine serum (FBS) and 1 mg/$m\ell$ G418 for two weeks. Individual clones were picked and each was amplified for further characterization. The genomic DNA from neomycin-resistnt cells was isolated and characterized by PCR using AcNPV IE1 gene-specific primers and by Southern blot analysis using neomycin gene probe. We concluded that AcNPV IE1 gene was functional in B. moridrived Bm5 cells as well as Spodaptera frugiperda-derived Sf9 cells to produce stably-transformed insect cells.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.295-302
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• 1998

The RNA genome of poliovirus encodes a long polyprotein precursor and this polyprotein is cleaved proteolytically by viral protease to yield mature proteins. The mature proteins derived from the P1 polyprotein precursor are the component of capsids. To further delineate the process of capsid assembly and encapsidation, in a first attempt, a cell line which expresses the authentic P1 polyprotein was established. CV-1 cells were transfected with the pRCRSVS1P1 plasmid DNA which contains 5'ncr sequences, whole authentic capsid gene of poliovirus and neomycin resistance gene. These cells were treated with G418 for 3 months, and eventually G418 resistant cells were selected and formed colonies. Each colony was picked and grown in the media containing G418. DNA analysis indicated that 1 of 13 neomycin resistant cell lines (R2-18) contains whole poliovirus P1 capsid gene segment which was incorporated into the genome. Immuneprecipitation of cell lysates with sera from rabbit immunized with inactivateded Sabin type 1 particles demonstrated the constitutive expression of the poliovirus P1 capsid protein from R2-18.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.155-164
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• 2004

This involves identifying and cloning trapped genes from cultured cells carrying the gene-trap constructs and generating cloned zebrafish using these cells for functional study. Gene-trapping studies in gene-trapped cells were carried out in initial and cloned zebrafish carrying gene-trap events were successfully produced based on the nuclear transplantation technique. Two kind of retroviral gene-trap constructs were adopted. The first one(SA/GFP-TP), constructed in my laboratory, carries a GFP reporter gene containing a splicing acceptor and an internal neo gene. The second one(Neo-TP), obtained from Dr. Hicks (Hicks et al., 1997), contains a promoter-less neo gene located in the LTR sequence of a retroviral vector. The infected cells were subjected to drug selection(neomycin treatment) because the two constructs carry the neomycin resistant gene. All those cells survived the neomycin treatment should carry the proviral insertions. For Neo-TP, Isolated DNA from the neomycin-resistant fibroblast cells infected by Neo-TP, was digested with EcoR1 restriction enzyme and transformed into bacteria after ligation. This procedure led to the isolation of seven clones carrying flanking cellular DNA with a typical retroviral integration signature sequence. These clones contained genomic DNA ranging from 1kb to 7kb and sequences of 300-600 bp were obtained from each of the rescued plasmids. Database searching showed that all of them share high homology to zebrafish sequences. For fish cloning using tagged cells, initially, nucleus donors directly selected from a mixture of cells(Neo-TP cells) were used. A total of 44 embryos(3.7%) out of 1179 transplants were reached blastula stage; 8 of these embryos(0.8%) hatched and 3(0.3%) of them survived to adulthood. One out of three lived cloned zebrafish has an amplified fragment and was labeled with 32P.

• KSBB Journal
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• v.6 no.1
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• pp.69-77
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• 1991

When S. fradiae was cultured in S medium, it stavted to produce neomycin in the middle of stationary phase of growth. Antibitoic production is regulated not only by glucose but also by metabolites formed from glucose. A chemically defined minimal salt broth was developen for the study of metabolites activating produition of antibiotic in a neomycin producer. When growth and production or antibiotic in minimal salt broth was examined with a full grown or a vefctativc mycelium, the medium was found not to be good for the growth, but to be good enough for the production of antibiotic with a full grown mycelium. When many carbotlydrates, organic acids, or alcohol were supplmented with instead of glucose in the medium suspcndcn with a full grown mycelium, the amount of antibiotic produced in the medium containing fumaratc was 5 times more than that in the medium with glucose. Further study indicated that the medium is not good also for the growth but good for the production of antibiotic. The antibiotic produced in this medium was identified to be neomycin. The activation of the production of neomycin by fumarate was further confirmed in a complex medium. Fuinarate is suspected to initiate and to activate the biosynthesis of neomycin at the gene level.

• BMB Reports
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• v.36 no.3
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• pp.275-281
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• 2003

An E1B-defective adenovirus, named r2/Ad carrying the neo expression cassette, was constructed by homologous recombination. The construction, selection (using neomycin as a selective marker), and propagation of the recombinant virus was performed in human embryonic kidney 293 cells (HEK 293). An in vitro study demonstrated that this recombinant virus has the ability to replicate in and lyse some p53-deficient human tumor cells such as human glioma tumor cells (U251) and human bladder cells (EJ), but not in some cells with functional p53, such as human adenocarcinoma cells (A549) and human fibroblast cells (MRC-5). Also, based on the cytopathic effect (CPE), it was demonstrated, under identical conditions, that the U251 cells were more sensitive to r2/Ad replication than the EJ cells. In this paper, we report that r2/Ad could be very useful in studying the in vitro selective replication of E1B-defective adenovirus and has great potential in cancer gene therapy.

• Plant Resources
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• v.4 no.1
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• pp.36-40
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• 2001

Transgenic Petunia hybrida cv. Rosanpion was produced by Agrobactepium tumefaciens LBA4404 harboring a binary vector pBI 121 containing $\beta$-glucuronidase (gus) and neomycin phosphotransferase (nptII). For genetic transformation, leaf discs were precultured on MS medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BA (MNB) for 2 days and cocultured for 15 mins with A. tumefaciens. For selection of transformant, leaf discs were transferred to fresh MNB containing 50 mg/L kanamycin and 500 mg/L cefotaxime. Eighteen plants were regenerated and four were confirmed by PCR for detection of gus and nptII gene integrated into the nuclear genome of petunia ‘Rosanpion’. Using this transformation system, we expect that transgenic petunia ‘Rosanpion’ incorporating a useful gene can be produced.

• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.116-119
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• 2007

The antimicrobial susceptibility and antibiotic resistance patterns of 67 eae positive Escherichia coli strains isolated from pigs were investigated by disc diffusion method. Sixty-seven E. coli isolated from pigs showed susceptibility to Ceftiofur (98.5%), Lincomycin+Spectinomycin (74.6%), Danofloxacin (73.1%), Enrofloxacin (64.2%), and Neomycin (41.8%). However, the multiple resistance patterns were also seen in eae+E. coli isolates. Neomycin+Tylosin+Penicillin+Tetracycline, Tylosin+Penicillin+Tetracycline, and Neomycin+Tylosin+Danofloxacin+Penicillin+Tetracycline+Enrofloxacinwere the most prevalent patterns of multiple antibiotic resistance.

• Journal of Life Science
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• v.23 no.9
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• pp.1133-1139
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• 2013

During the collection of boar semen, bacterial contamination usually occurs. The contamination has deleterious effects both on semen quality and on sow fertility. The majority of contaminants are gram-negative bacteria, especially Serratia marcescens. In this study, we developed a PCR assay for the identification of S. marcescens targeting the luxS gene (GenBank no. EF164926). S. marcescens yielded a specific 306 bp PCR product. However, no amplification was observed in the other strains tested. The detection limit of PCR was $50pg/{\mu}l$ of template DNA of S. marcescens. The antimicrobial susceptibility patterns of S. marcescens isolated from boar semen were tested using the disk diffusion method. Gentamicin, ceftiofur, florfenicol, and neomycin showed high sensitivity in this test. The minimum inhibitory concentration (MIC) was also determined by the broth microdilution method. The $MIC_{90}$ values of ceftiofur, enrofloxacin, gentamicin, and neomycin were 8, 8, 8, and $16{\mu}g/ml$, respectively. These results indicate that PCR amplification of the luxS gene is a reliable and effective method for the identification of S. marcescens and that ceftiofur, enrofloxacin, gentamicin, and neomycin are effective semen extenders for controlling S. marcescens.