• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.676-684
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• 1998

Baculovirus transfer and expression vectors with Hyphantria cunea nuclear polyhedrosis virus (HcNPV) were constructed. An initial transfer vector, pHcEV, constructed using HcNPV was previously reported (Park et al. 1993. J. Kor. Soc. Viral. 23: 141-151). Herein, the size of the vector was properly reduced, and a functionally perfect vector was constructed and named pHcEV-IV (6.7 kb). The vector has a 2.2-kb HcNPV DNA sequence in the 5'-flanking region of the vector's polyhedrin gene promoter. The 1.8-kb HcNPV DNA sequence, poly A signal sequence, T3 primer sequence, and 13 multicloning site sequences, in order, were ligated in front of the translation start codon of the polyhedrin gene. The cloning indicating marker lacZ gene was inserted into the pHcEV-IV, named pHcEV-IV-lacZ, and transferred into the wild-type virus. Recombinant expression virus, lacZ-HcNPV, was constructed by replacing the lacZ gene in the pHcEV-IV-lacZ with the polyhedrin gene of the wild-type virus. The recombinant virus was isolated from blue plaques that produce $\beta$-galactosidase without polyhedra. The lacZ gene insertion was confirmed by Southern hybridization analysis. The expression of the lacZ gene in Spodoptera frugiperda cells infected with the lacZ-HcNPV was examined by SDS-PAGE and colorimetric assay. One 116-kDa LacZ protein band appeared on the PAGE. The production rate of the $\beta$-galactosidase was approximately 50 international units (IU) per min per ml between 2 to 5 days postinfection (p.i.). The highest activity occurred at five days p.i. was 170 IU/min/$m\ell$. The enzyme activity first appeared about 20 h p.i. as measured by colorimetric assay.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.541-547
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• 1999

Constructions of a transfer vector and a recombinant baculovirus using the thymidine kinase gene of the Herpes simplex virus type 1 strain F (HSV -1) were carried out. Newly cloned transfer vector, pHcgXIIIB, was constructed by insertion of the glycoprotein gX gene signal peptide sequence of Pseudorabies virus into the baculovirus vector pHcEV-IV. The gX sequence was inserted just downstream from the promoter for the polyhedrin gene of the Hyphantria cunea nuclear polyhedrosis virus (HcNPV). HSV-1 thymidine kinase(tk) gene (1.131 kb) was used as a candidate gene for transferring into the baculovirus expression system. The tk gene was inserted into a BamHI site downstream from the gX sequence-promoter for the polyhedrin gene in the pHcgXIIIB transfer vector and was transferred into the infectious lacZ-HcNPV expression vector. Recombinant virus was isolated and was named gX-TK-HcNPV. The recombinant virus produced a 45 kDa gX-TK fusion protein in Spodoptera frugiperda cells, which was confirmed by Western blot analysis. Microscopic examination of gX-TK-HcNPV-infected cells revealed normal multiplication. Fluorescent antibody staining indicated that the gX-TK fusion protein was present in the cytoplasm. These results indicated that the transfer vector successfully transferred the gX-tk gene into the baculovirus expression system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.288-295
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• 2005

OFDM communications system is very attractive for the high data rate wireless transmission. However, it may be distorted in the nonlinear HPA since OFDM signal has high PAPR. So, a new SLM method using dummy sequence is studied for reducing the PAPR, and we call it DSI-SLM method. Unlike the conventional SLM method using the phase rotation, dummy sequences for PAPR reduction are assigned at the predefined sub-carriers. After IFFT, the OFDM data signal of the lowest PAPR is selected to transmit. So, it can cut down the computational complexity because it does not require the transmission and demodulation process of side information about the phase rotation. This proposed method can solve the time delay problem so that PAPR reduction can be made in real time processing.

• Reproductive and Developmental Biology
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• v.37 no.3
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• pp.109-115
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• 2013

Until recently the most popular tetracycline-inducible gene expression system has been the one developed by Gossen and Bujard. In this study, we tested the latest version of same system and the results are summarized as follows: Compared with previous one, the difference of new system are minor changes of nucleotide sequences in transactivator and tetracycline response element (TRE) regions. Sensitivity to the doxycycline (a tetracycline derivative) was improved. Leakiness of GFP marker gene expression in non-inducible condition was significantly decreased. Higher expression of the marker gene was observed when the cells were fed with doxycycline-containing medium. Optimal insertion site of woodchuck posttranscriptional regulatory element (WPRE) sequence which was known to increase gene expression was different depending on the origin of cells. In chicken embryonic fibroblast, location of WPRE sequence at 3' end of TRE resulted in the highest GFP expression. In bovine embryonic fibroblasts, 3' end of transactivator was the best site for the GFP expression.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1065-1069
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• 2009

Of 143 clinical isolates of Klebsiella pneumoniae collected from Korean non-tertiary hospitals, 24 (16.8%) showed an extended-spectrum ${\beta}$-lactamase-positive phenotype. PCR and sequence analysis revealed the presence of TEM-116 (n=13), CTX-M-3 (n=5), CTX-M-14 (n=2), CTX-M-15 (n=3), and SHV-12 (n=16). Each of the 24 isolates encoded more than one ${\beta}$-lactamase, and seven isolates (29%) harbored two different SHV-type ${\beta}$-lactamase genes ($bla_{SHV-11}$ and $bla_{SHV-12}$) bounded by insertion sequence IS26 in a single transferable plasmid.

• Biomedical Science Letters
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• v.11 no.2
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• pp.109-113
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• 2005

From the RT-PCR amplifications using mRNA templates isolated from Sprague-Dawley rat brains, we isolated a cDNA fragment of 1,524 bp which covered the full coding information of the rat brain CYP2El. Its nucleotide sequence was identical to the previously reported rat liver CYP2El mRNA except for the difference of one base (A to C at the nucleotide position 73). This difference also altered the amino acid Lys to GIn. However, no insertion or deletion of nucleotide(s) which could alter the reading frame was found within the structure of this rat brain CYP2El. This study should provide the molecular basis regarding the pathophysiological function of CYP2El in the brain.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.331-342
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• 2005

In this paper, we propose an efficient watermarking algorithm using block indexing. The proposed algorithm is a novel blind watermarking scheme using the indexed watermark value based on the spread spectrum method. The watermark insertion is allocated into index value of each block after dividing original image into sub-blocks. The watermark embedded in mappinged with index values of blocks, And the mappinged blocks convert to DCT and then the PN sequence embedded to middle frequency band. Consequently the watermark is expressed by index value of sub-blocks. The watermark extracted from the correlation of between PN sequence and watermarked image. Experimental results demonstrate that the watermarked image has a good quality in terms of imperceptibility and is robust against various attacks.

• Journal of Microbiology
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• v.42 no.2
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• pp.139-142
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• 2004

To identify genes involved in the decolorization of brilliant green, we isolated random mutants generated by transposon insertion in brilliant green-decolorizing bacterium, Citrobacter sp. The resulting mutant bank yielded 19 mutants with a complete defect in terms of the brilliant green color removing ability. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 7 mutants and these mutants appeared to have insertions at different sites of the chromosome. Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. By comparing these with a sequence database, putative protein products encoded by bg genes were identified as follows: bg 3 as a LysR-type regulatory protein; bg 11 as a MalG protein in the maltose transport system; bg 14 as an oxidoreductase; and bg 17 as an ABC transporter. The sequences deduced from the three bg genes, bg 2, bg 7 and bg 16, showed no significant similarity to any protein with a known function, suggesting that these three bg genes may encode unidentified proteins responsible for the decolorization of brilliant green.

• Genomics & Informatics
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• v.11 no.4
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• pp.164-173
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• 2013

Genomic instability, which occurs through both genetic mechanisms (underlying inheritable phenotypic variations caused by DNA sequence-dependent alterations, such as mutation, deletion, insertion, inversion, translocation, and chromosomal aneuploidy) and epigenomic aberrations (underlying inheritable phenotypic variations caused by DNA sequence-independent alterations caused by a change of chromatin structure, such as DNA methylation and histone modifications), is known to promote tumorigenesis and tumor progression. Mechanisms involve both genomic instability and epigenomic aberrations that lose or gain the function of genes that impinge on tumor suppression/prevention or oncogenesis. Growing evidence points to an epigenome-wide disruption that involves large-scale DNA hypomethylation but specific hyper-methylation of tumor suppressor genes, large blocks of aberrant histone modifications, and abnormal miRNA expression profile. Emerging molecular details regarding the modulation of these epigenetic events in cancer are used to illustrate the alterations of epigenetic molecules, and their consequent malfunctions could contribute to cancer biology. More recently, intriguing evidence supporting that genetic and epigenetic mechanisms are not separate events in cancer has been emerging; they intertwine and take advantage of each other during tumorigenesis. In addition, we discuss the collusion between epigenetics and genetics mediated by heterochromatin protein 1, a major component of heterochromatin, in order to maintain genome integrity.

• Journal of Life Science
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• v.10 no.1
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• pp.32-36
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• 2000

Solitary long terminal repeats(LTRs) of human endogenous retrovirus K family(HERV-K) have been found to be coexpressed with sequences of closely located genes. It has been suggested that HERV-K LTR-like elements entered the primate genome approximately 33-40 million years ago. WE investigated the presence of HERV-K LTR elements in New World monkeys using PCR amplification. Six LTR elements of HERV-K family were identified from New World monkeys, represented by the squirrel and night monkeys. They showed a high degree of sequence homology(96-99%) with the human-specific HERV-K LTR elements. Phylogenetic analysis reveals that an LTR element (SM-1) from the squirrel monkey and another LTR element (NM-1) from the night monkey are very closely related to the human-specific HERV-K LTR elements with low degree of divergence. This finding suggests that some of LTR elements of HERV-K family have recently been proliferated in New World monkeys. A sequence in chromosome Xq26(AL034407) \ulcorner contains an HERV-K LTR element was shown to be present in the human genome, but is absent in the bonobo, chimpanzee, gorilla, orangutan, and gibbon. It has more than 99% homology to other human-specific HERV-K LTR elements. This sequence thus represents and isolated insertion of an evolving class of elements that may have made a particular contribution to human genomic plasticity.