• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2000.06a
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• pp.64-75
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• 2000

During the last three decades considerable advances has been made in goat embryo production and transfer technology. The Korean native black goat is the most useful domestic ruminant in this country for biological investigation and application because it has a lot of merits such as relatively short generation period(1 vs 2 year for a cow), easy of handling, well adaptation, high fertility, convenient and inexpensive. This article covers the methods of superovulation, estrus synchronization, embryo collection and transfer techniques, pregnancy diagnosis and subsequent pregnancy and kidding rates for the production of transgenic Korean native black goats. More than one hundred goat kids have been produced as a result of our transgenic goat project via microinjection of foreign gene into pronuclei, in vitro culture, transfer of various stages of fresh and frozen-thawed microinjected embryos into oviducts or uteri of recipient does. We have got two transgenic goats carrying a transgene targeting the expression of recombinant human granulocyte colony stimulating factor(hG-CSF) to the mammary gland so far. Since collection and transfer of embryos in this species is usually accomplished by laparotomy, exteriorization of the reproductive tract for surgical embryo collection leads to the formation of post-operative adhesions. Nonsurgical or laparoscopic technique to reduce adhesions from repeated surgeries has great advantages in improving embryo production and transfer especially from valuable donors. We will discuss this later.

• Journal of Aquaculture
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• v.16 no.1
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• pp.51-58
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• 2003

The first Indian transgenic fish was generated in 1991 using borrowed constructs from foreign sources. To construct transformation vectors for the indigenous fishes, growth hormone genes of rohu (r-CH), Labeo rohita and catfish, Heteropneustes fossilis were isolated, cloned and sequenced; their fidelity was confirmed in prokaryotic and eukaryotic systems. A vector was constructed with grass carp b-actin promoter driving the expression of r-GH. Rohu eggs are large. fragile and swell 2~3 times. when fertilized. Hence they were amenable only for electroporated sperm-mediated gene transfer. Accordingly, the sperm electroporation technique was standardized to ensure 25% hatchling survival and 37% Presumptive transgenics without suffering any deformity. Southern analysis confirmed genomic integration in 15% of the tested individuals (Ti) belonging to family lines 2 and 3: another 25% of the Juveniles (Te) were also proved transgenic but with the transgene persisting extrachromosomally for longer than 1 to 2 years. perhaps due to the presence of replicon in the vector. Transgenics belonging to different family lines grew 6~8 times faster than the respective controls. Difference in growth trends of Ti and Te within a family line was not significant. In the Ti family 3 remarkable growth acceleration was sustained for a period longer than 36 weeks but in those of family 2, it gradually decreased. All transgenic fishes including the rohu converted the food at a significantly higher efficiency. Barring the transgenic mudloach, all the other transgenic fishes consumed food at significantly reduced rate.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.235-238
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• 2011

Agrobacterium harboring vector pCHBs with hygromycin phosphotransferase(hph) and hepatitis B virus surface antigen(HBsAg)gene was transformed into the mycelial culture of Flammulina velutipes. In particular, mild NaOH solution was treated to the mycelia before Agrobacterium infection step. This was purposed to generate putative surface wounds in the mycelial cell walls. The results showed that hygromycin-resistant($hyg^r$) mycelia could be obtained only from NaOH-treated mycelia but not from intact mycelia. The integration of $hyg^r$ gene in fungal genome was confirmed by PCR. In addition, a single transgene integration and heterologous protein expression in F. velutipes could be verified by Southern blot hybridization and western blot analysis, respectively. This study demonstrated an efficient tool for the Agrobacterium-mediated transformation of F. velutipes mycelia.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.126-126
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• 2003

Sucrose-phosphate synthase (SPS) is a key regulatory enzyme in sucrose synthesis. To investigate the role of SPS in carbon partitioning, we produced transgenic rice plants overexpressing a cyanobacterial SPS from Synechocystis sp. PCC 6803. The gene was expressed under the control of the maize Ubil promoter in transgenic plants. Southern and Northern blot analyses confirmed the integration and the expression of the transgene in four transgenic rice lines. All of the four transgenic! lines analyzed showed abnormal vegetative and reproductive developments. Analysis of SPS activities and primary metabolites in the transgenic rice plants will be presented.

• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.73-78
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• 2007

The green revolution has significantly helped in increasing the food production. So far, various breeding methods have been exploited, besides them recombination DNA technology provides another approach for increasing the food production. By means of this technology the losses in food production incurred by various biotic and abiotic stresses can be effectively controlled. In most of the transgenic studies scientists have used antibiotic resistant genes as markers for easy selection of transformants but there are risks involved in use of GM foods. To make such foods safer and environment friendly we have discussed a novel strategy i.e. Cre-lox which involves site specific recombination. By means of Cre-lox the marker genes can be specifically removed once the selection of transformants is over. In addition, this strategy can be used to module the hybrid chromosomes, avoid gene silencing and incorporate single copy of a transgene for its higher expression.

• Korean Journal of Plant Tissue Culture
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• v.22 no.4
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• pp.201-205
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• 1995

The synthetic oligomers called nos right palindrome (RP) element and left palindrome (LP) element were inserted into nos.minimal promoter nos 5'-101 deletion mutant The activity of nos promoter was measured by studying the expression pattern of gene fusion between nos promoter and reporter genes such as chloramphenicol acetyltransferase and $\beta$-glucuconidase. Analysis of transgenic tobacco plane carrying transgene showed that the activity of nos minimal promoter activity was recovered by insertion of synthetic nos RP element. Nos RP element insertion of nos minimal promoter was induced by auxin, dithiothreitol, salicylic acid and methyl jasmonate.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.47-58
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• 2008

To select agronomically useful transgenic plants, a large number of transgenic events are initially produced, gene transfer confirmed, and advanced to obtain homozygous lines for testing in field trials. Direct in planta assays for identifying the transgene carriers in the segregating progeny are based on the activity of selectable marker gene and are easy, simple and inexpensive. For this purpose, expression of bar gene as measured by tolerance to damage by glufosinate ammonium, the active ingredient in the herbicide BASTA, was investigated. Dose damage curves were generated by leaf paint tests with BASTA on four genotypes of sorghum. Transgenic plants were characterized in terms of sensitivity to the concentration of glufosinate ammonium. In transgenics, symptoms of BASTA swab tests at different growth stages and PCR analysis for cry1B were carried out and correlated. Germination tests could not be employed for large scale evaluation of transgenic progeny because of mortality of tolerant seedlings after transplantation to soil. Based on the above findings, a simple, inexpensive, time-saving, two-step scheme for effective evaluation of transgenics and their progeny containing bar gene as selection marker using BASTA swab tests is described.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.46-52
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• 2001

To evaluate the non-ionic polymer, poly(ethylene glycol) (PEG), as a component in cationic copolymers for non-viral gene delivery systems, PEG was coupled to polyethylenimine (PEI). We present the effects of different degrees and shapes of pegylation of PEI on cytotoxicity, water solubility and transfection efficiency. This work reports the synthesis and characterization of a series of cationic copolymers on the basis of the conjugates of PEI with PEG. The modified molecules were significantly less toxic than the original polymer. Moreover, the chemical modification led to enhancement of their solubility. The comparison of pegylated PEIs with different degrees of derivation showed that all the polymers tested reached comparable levels of transgene expression to that of native PEI. As assessed by agarose gel electrophoresis, even highly substituted PEI derivatives were still able to form polyionic complexes with DNA. However, aside from an increase in solubility and retention of the ability to condense DNA, methoxy-PEG-modified PEIs resulted in a significant decrease in the transfection activity of the DNA complexes. In fact, the efficiency of the copolymer was compromised even at a low degree of modification suggesting that the PEG action resulting from its shape is important for efficient gene transfer. The mode of PEG grafting and the degree of modification influenced the transfection efficiency of PEI.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1390-1394
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• 2004

We have achieved efficient transformation system for forage-type tall fescue plants by Agrobacterium tumefaciens. Mature seed-derived embryogenic calli were infected and co-cultivated with each of three A. tumefaciens strains, all of which harbored a standard binary vector pIG121Hm encoding the neomycin phosphotransferase II (NPTII), hygromycin phosphotransferase (HPT) and intron-containing $\beta$-glucuronidase (intron-GUS) genes in the T-DNA region. Transformation efficiency was influenced by the A. tumefaciens strain, addition of the phenolic compound acetosyringone and duration of vacuum treatment. Of the three A. tumefaciens strains tested, EHA101/pIG121Hm was found to be most effective followed by GV3101/pIG121Hm and LBA4404/pIG121Hm for transient GUS expression after 3 days co-cultivation. Inclusion of 100 $\mu$M acetosyringone in both the inoculation and co-cultivation media lead to an improvement in transient GUS expression observed in targeted calli. Vacuum treatment during infection of calli with A. tumefaciens strains increased transformation efficiency. The highest stable transformation efficiency of transgenic plants was obtained when mature seed-derived calli infected with A. tumefaciens EHA101/pIG121Hm in the presence of 100 $\mu$M acetosyringone and vacuum treatment for 30 min. Southern blot analysis indicated integration of the transgene into the genome of tall fescue. The transformation system developed in this study would be useful for Agrobacterium-mediated genetic transformation of tall fescue plants with genes of agronomic importance.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.79-82
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• 2000

We have isolated a cDNA encoding a calcium-dependent protein kinase (CDPK) in Nicotiana tabacum, which was designated NtCDPK1. Accumulation of the NtCDPK1 mRNA was stimulated by various stimuli, including phytohormones, CaCl$_2$ wounding, fungal elicitors, chitin and methyl jasmonate. The NtCDPK1 gene encodes a functional Ser/Thr protein kinase of which phosphorylation activity is strongly induced by calcium. By analyzing expression of the NtCDPK1-GFP fusion protein and by immunoblotting with antibody which reacts with NtCDPK1, we found that NtCDPK1 is localized in membrane and nucleus in plant cells. Silencing expression of the NtCDPK1 transgene resulted in marked decrease of lateral root development in the transgenic tobacco plants. Yeast two hybrid screening using NtCDPK1 as a bait identified a tobacco homologue of proteasome regulatory subunit 21D7, designated Nt21D7. The 21D7 mRNA has been shown to be predominantly expressed in proliferating tissues in the cell cycledependent manner in carrot. The recombinant NtCDPK1 protein associated with Nt21D7 in vitro, and could phosphorylate the Nt21D7 protein in vitro in the presence of calcium, suggesting that Nt21D7 protein is a natural substrate of NtCDPK1 in tobacco. These results suggest that NtCDPK1 may regulate tell proliferation processes, such as lateral root formation, by regulating specificity and/or activity of proteasome-mediated protein degradation pathway.