• Journal of Plant Biotechnology
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• 제31권3호
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• pp.185-190
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• 2004

Agrobacterium을 이용한 GUS 유전자를 효과적으로 발현시키기 위하여 수행되어진 실험 결과를 요약하면 다음과 같다. 박테이라 농도별 실험을 수행한 결과 균의 전처리 배양 농도 O $D_{600nm}$ 0.3일때 원심분리한 후 얻어진 균을 희석한 후의 최종 농도는 O $D_{600nm}$ 0.8로 맞춘 실험 처리구에서 GUS 유전자 발현율이55%로 가장 높게 나타났다. 병원성 유도 배지 내에 Acetosyringone (AS)이 첨가되지 않은 경우 GUS 유전자가 발현된 고추 잎을 얻을 수 없었으나, 200$\mu$M을 첨가했을 때 90%의 가장 높은 GUS 유전자 발현율을 나타내어 많은 수의 GUS spots을 관찰할 수 있었다. Agrobacterium에 의한 고추 잎의 감염 정도를 조사한 바 Agrobacterium으로 감염시킨지 3일째부터는 박테리아 에한 감염 정도가 심해져서 GUS 유전자 발현 정도가 약해지므로 Agrobacterium으로 감염시킨지 2일째 되었을 때 GUS 유전자 발현이 가장 강하게 나타난 것을 확인하였다. 이 같은 결과는 박테리아에 의한 감염이 일어난지 3일째 부터는 식물체의 감염부위 고사를 일으키는 것과 관련된 것으로 보인다.

• 생태와환경
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• 제52권4호
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• pp.394-402
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• 2019

The Agrobacterium tumefaciens mediated gene transfer is widely used to generate genetic transformation of plants and transient assay of temporal exogenous gene expression. Syringe infiltration system into tobacco (Nicotiana benthamiana) leaves is a powerful tool for transient expression of target protein to study protein localization, protein-protein binding and protein production. However, the protocol and technical information of transient gene expression, especially double strand RNA (dsRNA), in tobacco using Agrobacterium is not well known. Recently, dsRNA is crucial for insecticidal effect on destructive agronomic pest such as Corn rootworm. In this study, we investigated the factor influencing the dsRNA expression efficiency of syringe agro-infiltration in tobacco. To search the best combination for dsRNA transient expression in tobacco, applied two Agrobacterium cell lines and three plant vector systems. The efficiency of dsRNA expression has estimated by real-time PCR and digital PCR. As a result, pHellsgate12 vector constructs showed the most effective accumulation of dsRNA in the cell. These results indicated that the efficiency of dsRNA expression was depending on the kind of vector rather than Agrobacterium cells. In summary, the optimized combination of transient dsRNA expression system in tobacco might be useful to in vivo dsRNA expression for functional study and risk assessment of dsRNA.

• 농업생명과학연구
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• 제45권6호
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• pp.193-199
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• 2011

An efficient transient expression system has been developed and characterized for the production of foreign genes in seedlings. The seedlings can be easily produced from commercial seeds used for vegetable sprouts. In principal, a chemical abrasive was employed to generate wounds in seedlings prior to vacuum-infiltration with Agrobacterium tumefaciens bearing the target gene. This optimized chemical wounding-assisted agro-infiltration process resulted in up to 15-fold increase in $\beta$-glucuronidase (GUS) enzyme activity. This procedure has been used efficiently to express hepatitis B surface antigen (HBsAg) protein in a transient mode. Therefore, seedlings with proper wounds can be suggested as a convenient tool for the production of useful recombinant proteins.

• KSBB Journal
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• 제21권6호
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• pp.489-492
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• 2006

분자육종의 목적을 위하여 Agrobacterium을 이용한 Brassica napus 식물의 유전적 형질전환은 폭 넓게 시행되어 왔다. B. napus cv. napus는 유지작물의 하나이면서 이 또한 Agrobacterium을 이용한 형질전환이 가능하다. 본 연구에서는 agroinfiltration방법을 이용시 유채유묘의 형질전환이 낯은 효율로 나타나고 있으며 이는 fluorometric GUS assay에 의하여 판단되었다. 대조적으로 유채유묘에 대하여 sodium hydrosulfite 용액을 agroinfiltration 과정 이전에 처리할 경우 형질전환율이 상당히 증가하는 것을 관찰할 수 있었다. RT-PCR에 의한 GUS유전자발현의 확인을 통하여 유채유도를 이용한 일시발현체계의 개발가능성을 제시하였다.

• Journal of Plant Biotechnology
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• 제7권2호
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• pp.113-121
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• 2005

The objective of this study was to identify the major parameters controlling DNA delivery by particle bombardment to immature embryos of Chinese spring wheat (Triticum aestivum L.). Efficiency of DNA (uidA gene) delivery was assessed by transient GUS (${\beta}$-glucuronidase) expression in bombarded tissues. Of the parameters analyzed, acceleration pressure, bombardment distance, chamber vacuum pressure, bombardment times, osmotic conditioning of culture had a remarkable influence on transient gene expression. A bombardment procedure suitable for Chinese spring wheat cultivars was developed which allowed high-efficiency DNA delivery combined with reduced damage to target tissues. The high efficiency made the system practical for wheat genetic transformation research and accelerating wheat breeding programs.

• 한국환경농학회지
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• 제40권3호
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• pp.186-193
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• 2021

BACKGROUND: Before generating transgenic plant using the CRISPR-Cas9 system, the efficiency test of sgRNAs is recommended to reduce the time and effort for plant transformation and regeneration process. The efficiency of the sgRNA can be measured through the transient expression of sgRNA and Cas9 gene in tomato cotyledon; however, we found that the calculated efficiency showed a large variation. It is necessary to increase the precision of the experiment to obtain reliable sgRNA efficiency data from transient expression. METHODS AND RESULTS: The cotyledon of 11^th, 15^th, 19^th, and 23^rd-day-old tomato (Solanum lycopersicum cv. Micro-Tom) were used for expressing CRISPR-Cas9 transiently. The agrobacterium harboring sgRNA for targeting ALS2 gene of tomato was injected through the stomata of leaf adaxial side and the genomic DNA was extracted in 5 days after injection. The target gene edition was identified by amplifying DNA fragment of target region and analyzing with Illumina sequencing method. The target gene editing efficiency was calculated by counting base deletion and insertion events from total target sequence read. CONCLUSION: The CRISPR-Cas9 editing efficiency varied with tomato cotyledon age. The highest efficiency was observed at the 19-day-old cotyledons. Both the median and mean were the highest at this stage and the sample variability was also minimized. We found that the transgene of CRISPR-Cas9 system was strongly correlated with plant leaf development and suggested the optimum cotyledon leaf age for Agrobacterium-mediated transfection in tomato.

• 한국잠사곤충학회지
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• 제39권1호
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• pp.36-43
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• 1997

In order to express the FLP recombinase in B. mori cultured cell line, BmN-4, transient expression system using a heat shock protein gene (hsp70) promoter of Dorosophilla melnogaster was constructed. This vector was designated as pHsSV. Activity strength of the hsp70 promoter was compared with that of immediate early gene (IE-1) and polyhedrin gene of BmNPV employing the E. coli $\beta$-galactosidase gene as a reporter gene. The result showed that the pHs $\beta$-gal plasmid vector expressed the $\beta$-galactosidase at 2nd and 3rd day after the transfer of plasmid DNA into BmN-4 cells, which was similar to that of pIE1 $\beta$-gal vector, but different from that of a recombinant virus, vBm $\beta$-gal. For the construction of FLP recombinase transient expression vector, the FLP recombinase gene was cloned by polymerase chain reaction technique. To express the FLP recombinase, this gene was inserted into pHsSV plasmid vector, under the control of the hsp70 promotor, and tranfected in BmN-4 cells. The expressed FLP recombinase was estimated at 44kDa on a 12.5% SDS-PAGE.

• International Journal of Oral Biology
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• 제41권3호
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• pp.119-123
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• 2016

Acetylcholine receptors (AChR) including muscarinic and nicotinic AChR are widely expressed and mediate a variety of physiological cellular responses in neuronal and non-neuronal cells. Notably, a functional cholinergic system exists in oral epithelial cells, and nicotinic AChR (nAChR) mediates cholinergic anti-inflammatory responses. However, the pathophysiological roles of AChR in periodontitis are unclear. Here, we show that activation of AChR elicits increased cytosolic $Ca^{2+}([Ca^{2+}]_i)$, transient cytotoxicity, and induction of receptor activator of nuclear factor kappa-B ligand (RANKL) expression. Intracellular $Ca^{2+}$ mobilization in human gingival fibroblast-1 (hGF-1) cells was measured using the fluorescent $Ca^{2+}$ indicator, fura-2/AM. Cytotoxicity and induction of gene expression were evaluated by measuring the release of glucose-6-phosphate dehydrogenase and RT-PCR. Activation of AChR in hGF-1 cells by carbachol (Cch) induced $[Ca^{2+}]_i$ increase in a dose-dependent manner. Treatment with a high concentration of Cch on hGF-1 cells caused transient cytotoxicity. Notably, treatment of hGF-1 cells with Cch resulted in upregulated RANKL expression. The findings may indicate potential roles of AChR in gingival fibroblast cells in bone remodeling.

• 한국가축번식학회지
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• 제25권3호
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• pp.277-286
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• 2001

기존의 미세주입 및 정자 electroporation에 의한 보다 효율적인 유전자 도입방법을 개선하여 간단하고 고효율성의 유전자 변환기술을 위한 유전자 도입장치의 시제품 개발로 다수의 난자를 전기적으로 단순화할 수 있는 상업화의 가능성을 보여주었다. 도입된 유전자는 모든 초기배에서 발현됨을 보여 주었다. 특히 난황내의 합포체세포(syncytium)에서의 transient성의 강한 발현은 전기자극에 의해 많은 수의 난자에 유전자를 도입하고 100% 발현되는 체계를 이용하여 transient 시기에서 인간 유용단백질 생산의 가능성을 타진할 수 있는 결과를 보여 주었다. 어류유전자 발현의 작동되는가를 검색하기 위해 신경세로조직특이 tubulin promoter 를 이용한 결과 gfp의 발현이 뇌주변과 척추를 중심으로 체내 전반의 신경세포내에 발현이 강하게 나타남을 보여 주었다. 한편 reporter 유전자 이외에 간세포로부터 전체 RNA를 분리시켜 vitellogenin의 분해산물인 phosvitin cDNA의 길이와 promoter지역인 1.6 kb에 대한 primer쌍들을 선정한 상태에서 PCR에 의해 각각 cDNA와 gDNA로부터 cloning 중에 있으며 human factor Ⅶ과 epidermal growth factor, vitellogenin의 3종의 target 단백 질유전자를 구축 및 검정 화인 중에 있다.

• 원예과학기술지
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• 제34권2호
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• pp.314-323
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• 2016

A transient ihpRNA-induced gene silencing system based on Agrobacterium-mediated injection infiltration has been established to evaluate candidate genes involved in proanthocyanidin (PAs) biosynthesis in persimmon (Diospyros kaki Thunb.). We chose DkPDS (phytoene desaturase) as a gene-silencing target to evaluate the newly developed transient gene silencing system. Our qRT-PCR analysis indicated that two ihpRNA constructs (pHG-PDS5' and pHG-PDS3') targeted DkPDS, which also led to significantly reduce expression of DkPDS in 'Mopanshi' persimmon leaves. To further confirm the reliability of the system, we successfully utilized it for DkLAR (leucoanthocyanidin reductase) gene silencing. The expression levels of DkLAR in 'Mopanshi' and 'Eshi 1' leaves were ca. 6-fold and ca. 5-fold lower than those in leaves harboring empty vector (pHG-GFP), respectively. DMACA (4-dimethylaminocinnamaldehyde) staining and the Folin-Ciocalteau assay showed that the accumulation of PAs was markedly inhibited in 'Mopanshi', 'Eshi 1' and 'Youhou' leaves. These results indicate that DkLAR plays an important role in the accumulation of PAs in persimmon. The transient ihpRNA-induced gene silencing method developed in this study is a highly efficient and useful tool for functional analysis of persimmon genes involved in PA biosynthesis.