• Journal of Plant Biotechnology
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• v.45 no.3
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• pp.257-265
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• 2018

Sweetener is one of the additives that makes you feel sweet. Artificial sweeteners and sugar are typical examples, and sweetness proteins with sweetness characteristics have been widely studied. These studies elucidated the transformation lettuce cells with Agrobacterium method for stable production of natural sweet proteins, brazzein, thaumatin, and miraculin. In this paper, we report use of a plant expression system for production of sweet proteins. A synthetic gene encoding sweet proteins was placed under the control of constitutive promoters and transferred to lettuce. High and genetically stable expression of sweetener was confirmed in leaves by RT-PCR and Western blot analysis. Sweet proteins expressed in transgenic lettuce had sweetness-inducing activity. Results demonstrate recombinant sweet proteins correctly processed in transgenic lettuce plants, and that this production system could be a viable alternative to production from the native plant.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.66-73
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• 1996

For the effective control of mosquito larvae, Anopheles sinensis, the expression vector pCYASK5-1 containing cryIVD gene of Bacillus thuringiensis subsp. morrisoni PG-14 was constructed and transformed into the cyanobacterium Synechocystis PCC6803. The transformants were selected on BG-11 medium containing kanamycin. The expression of cryIVD gene in transformant was confirmed by SDS-PAGE and Western blot analysis. The mortality of A. sinensis larvae was scored for 3 days. Furthermore, growth and distribution rate of transformant were examined. The results showed that Synechocystis PCC6803 transformed with cryIVD gene of B. thuringiensis subsp. morrisoni PG-14 was highly toxic to A. sinensis larvae, demonstrating that it will be a potential agent for mosquito control.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.213-218
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• 1986

Hybrid plasmid pEA24, shuttle vector YRp7 carrying amylase gene of Bacillus amyloliquefaciens, was transformed to yeast Saccharomyces cerevisiae, and the expression of B. amyloliquefaciens amylase gene in yeast was investigated. The frequency of transformation to S. cerevisiae DBY747 with YRp7 was increased by treatment of 40% polyethylene glycol (MW 4, 000), PH 7.0, at 3$0^{\circ}C$, and by regeneration used 2% top agar. The amount of cellular amylase activity produced by S. cerevisiae containing pEA24 was 2% of that secreted from B. amyloliquefaciens, but in case of S. cerevisiae transformant, the amylase secreted was not detected. A comparison of genetic stability of pEA24 and YRp7 plasmids in yeast was carried out by cultivation of transformants in tryptophan-supplement-medium. The pEA24 plasmid was more unstable than YRp7 in S. cerevisiae. The size of pEA24 extracted from S. cerevisiae transformants was found to be identical with that from E. coli transformants by agarose gel electrophoresis.

• Journal of Life Science
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• v.11 no.5
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• pp.423-431
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• 2001

Genomic and cDNA clones containing the RAT3 gene involving in Agobacterium-mediated plant transformation were identified using plant DNA flanking the righ border of a T-DNA rescued from the rat3 mutant as hy-bridization probe. Two highly homologous cDNA clones were identified; one (RAT3-1) weakly hybridized with the probe whereas another (RAT3-2) strongly hybridized with the probe. Both Rat3-1 and Rat3-2 proteins contain a putative signal peptide for secretion. The deduced molecular weights of encoded proteins are 15 kDa. The results of genomic DNA blot analysis and DNA sequencing indicated that RAT3-1 and RAT3-2 exist as single copy genes and they were arranged side by side with just 600 bp distance between them. RAT3-1 was disrupted by the integration of T-DNA into the 3 untranslated region in rat3 mutant. A BLAST search showed that both RAT3-1 and RAT3-2 proteins have homology with only the C-terminal region of $\beta$-1,3-glucanase homologues from Triticum aestivum and Arabidopsis thaliana. Thses $\beta$-1,3-glucanase homologues contain an unusually long C-terminal region with no sig-nificant homology to other $\beta$-1,3-glucanase.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.161-168
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• 2004

Optimal regeneration conditions of ginseng transformants were studied. It has been known that Ferritin Light Heavy Chain (FLHC) gene remove the several heavy metal by combination, store and transport. To obtain the ginseng tolerant to heavy metal, binary vector was introduced in Agrobacterium by tri-parental mating and then Agrobacterium tumefaciens MP90/FLHC was selected on the AB media and MS media containing kanamycin. Explants were co-cultured with Agrobacterium tumefaciens MP90/FLHC, which contained NPT II as a selectable marker, tadpole ferritin heavy chain (FLHC) gene and human ferritin light chain gene and then a number of embryos were induced. The induced embryo transferred to shooting media consisting of MS medium supplemented with GA 10 mg/L. As a result of examination that induced the normal growth of transfomants, transformants showed the equivalent growth in both root and shoot on the media containing the 1/3 MS.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.177-181
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• 1998

This study was carried out to investigate activity difference in the superoxide dismutase (SOD) and peroxidase (POD) of tomato callus transformed with Agrobacterium containing the GUS gene. Than those of other two tomato cultivars, the hypocotyl explant of JA101 was shown to have higher POD and SOD specific activity of 23 unit/mg protein and 2,156 unit/mg protein, respectively. Relatively high frequency of callus formation was obtained from the hypocotyl explant on MS medium containing 1 mg/L 2,4-D for 30 days and its POD(47 unit/mg protein) and SOD (95,786 unit/mg protein) specific activities were higher than other 2,4-D concentration. The hypocotyl explant and callus cocultivated with Agrobacterium for 72 hours were transferred to MS medium supplemented with 1 mg/L 2,4-D, 30 mg/L kanamycin, 30 g/L sucrose and 4 g/L Gelrite. The hypocotyl explants transferred to the medium formed callus with 45.5% effeciency after 8 weeks. The transformation efficiency confirmed by GUS assay was 21.6%. POD specific activity of the transformed callus (54 unit/mg protein) were somewhat lower than the non-transformed callus (64 unit/mgg protein) and SOD specific activity of the transformed callus (30,300 unit/mg protein) were also lower than the non-transformed callus (37,077 unit/mg protein). However there was no significant difference in POD and SOD isozyme patterns between the transformed and the non-transformed calluses. From these results, it revealed that there was no difference of antioxidant enzyme activities between the transformed callus and the non-transformed callus in tomato.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.363-370
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• 2005

Neural stem cells (NSCs) of the central nervous system (CNS) have raised a great interest not only for their importance in basic neural development but also for their therapeutic potentials in neurologically degenerative diseases such as Parkinson's, Alzheimer and stroke. During the CNS development, two molecular cascades determine specification of midbrain dopamine system. In one pathway, FGF-8, sonic hedgehog and transcription factor Nurr1 specify dopamine neurotransmitter phenotype. In the other, transcription factors $Lm{\times}lb\;and\;Pt{\times}3$ are required for induction of dopaminergic neurons. In Nurr1 knockout mouse, tyrosine hydroxylase (TH) positive cells fail to appear in substantia nigra, indicating that Nurr1 is essential in specification of dopaminergic cell phenotype. In this study, we used the immortalized human NSCs retrovirally transduced with Nurr1 gene to probe the Nurr1 mediated mechanism to induce dopamine phenotype. While Nurr1 over-expression alone did not generate dopamine phenotype in NSCs, applications of retinoid and forskolin induced expression of TH and AADC mRNAs. In addition, co-cultures of Nurr1 expressing NSCs with human astrocytes induced a marked increase of TH expression. In this co-culture system, the addition of retinoid and forskolin dramatically increased expression of TH. These results indicate that the immortalized human NSCs with Nurr1 gene could have a clinical utility for cell replacement for the Parkinson patients.

• KSBB Journal
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• v.16 no.6
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• pp.568-572
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• 2001

Light is one of the most important environmental factors controlling plant physiology. The human granulocyte-macrophage colony-stimulating factor (hGM-CSF) was produced from cell suspension cultures of transgenic tobacco under different light conditions (24 hr light, 18 hr light/dark cycle, dark). Under 24 hr light condition, cell growth was best and dry cell weight reached 14.4 g/L. Light did not influenced the secretion of total proteins. However, in the dark condition, the ratio of secreted total protein/dry cell weight was 1.5 fold higher than those of ethel conditions. Production of hGM-CSF was highest with 18 hr light condition and reached 496.5 ug/L. In addition, the content of hGM-CSf in secreted total proteins was 1.8 fold higher than that of 24 hr light condition, which is beneficial for the purificationof the protein.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.171-180
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• 2001

Compared to other gene transfer system, the advantages of retrovirus-mediated gene transfer are technical ease, efficient expression and genetic stability. Despite the high potency of the retrovirus vector system in gene transfer, one of the drawbacks is a difficulty in concentration of virus stock. To overcome this problem, we tested a new retrovirus vector system producing the progeny retrovirus particles encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein). The infectivity of this virus was not sacrificed by ultracentrifugal concentration and the host cell range extended from all mammalian to fish embryos. Virus titer after 1,000 x concentration was more than 10$^{8}$ CFU/ $m\ell$ on most of the target cell lines. We applied this pantropic viruses in transgenic chicken production by injecting the concentrated (100$\times$) stock into subgerminal cavity of stage X chicken embryos. The survival rate of chicken embryos after injection was about 20% and gene integration rate in surviving embryos was scored almost 100%. Analyses of RT-PCR and fluorescence microscopy, however, showed no evidence of the transgene expression.

• Journal of Chest Surgery
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• v.27 no.2
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• pp.174-176
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• 1994

Castleman`s disease is characterized by lymph node enlargement. There are two distinct histologic subtypes, which are hyaline vascular and plasma cell type. We experienced one case of localized Castleman`s disease of plasma cell type, which located in hilum of the left lung.