• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.189-192
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• 2001

We have investigated the effects of abiotic and biotic stresses on leaf senescence using transgenic tobacco plants, in which cellular contents of polyamines were increased by introducing the genes of polyamine and ethylene biosynthesis in sense or antisense orientation. These transgenic plants showed accumulations of polyamines at higher levels than were found in wild-type. Stress-induced senescence was attenuated in transgenic plants cpmpared with wild-type plants, in terms of total chlorphyll loss and phenotypic changes after oxidative stress of hydrogen peroxide($H_2O_2$), high salinity, acid stress (pH3.0), ABA and fungal pathogen(phytophothora parasitica pv.Nicotianae). Transcripts for antioxidant enzyme, glutathionine-S-transferase and catalase, were also more abundant in transgenic plants than wild-type plants. These result suggested that higher expression of those genes caused a broad-spectrum resistance to abiotic stress/biotic stress. These phenomena indicate that polyamines may play an important role in contributing to the antioxidant defense function in plants. Our findings suggest that facilitate the improvement of stress tolerance of crop plants.

• Development and Reproduction
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• v.6 no.2
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• pp.71-76
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• 2002

Present study was aimed to summary the recent reports of chromosomal technology such like a polyploidv, sex differentiation, gynogenesis, transgenic fish and gene manipulation. Triploid cells for rainbow trout and channel catfish were induced through thermal shocks of varying temperature levels and produced as a industrial use. A monosex fish with homogametic females of 15 species of high valued fish were produced by exposing to irradiation. It seemed that different irradiation was suitable to inactivate the sperm and block the formation in producing the gynogenetic diploids. Since 1985, transgenic fish have been successfully produced by microinjecting or electroporating desired foreign DNA into unfertilized or newly fertilized eggs using about 40 fish species. More recently, transgenic fish have also been produced by infecting newly fertilized eggs with pantropic, defective retroviral vectors carrying desired foreign DNA. These transgenic fish can serve as excellent experimental models for basic scientific investigations as well as in marine biotechnological applications.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.75-79
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• 1983

To exploit a suitable vector and recipient strain for molecular cloning in Bacillus subtilis, oxytetracycline-resistant plasmic DNA has been prepared from Streptomyces rimosus by phenol-buffer extraction of lysozyme-lysed cells and introduced into B. subtilis KPM 60 [St $r^{R}$-mutant of RM 125 (leu A8, arg 15, hsm $M^{-10}$ , hsr $M^{-10}$ )] by transformation. Oxitetracycline-resistant plasmid was well transferred into B. subtilis KPM 60 with average frequency of 10$^{-4}$ per $\mu\textrm{g}$ of DNA. The highest frequency of plasmid transformation was obtained after 3 hours incubation of recipient cells in the growth medium and 30 to 60 minutes incubation in the competence medium, and then 20 minutes contact of DNA and host cells. Optimum pH for competence was 7.5, and optimum temperature for transformation was 2$0^{\circ}C$.>.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.53-58
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• 2001

To develop herbicide-resistant cucumber plants (Cucumis sativus L. cv Green Angle) embryogenic suspension cultures were co-cultured with Agrobacterium tumefaciens strain LBA4404 carrying a disarmed binary vector pGA-bar. The T-DNA region of this binary vector contains the nopalin synthase/neomycin phosphotransferase Ⅱ (npt Ⅱ) chimeric gene for kanamycin resistance and the cauliflower 35S/phosphinothricin acetyltransferase (bar) chimeric gene for phosphinothricin (PPT) resistance, After co-cultivation for 48 h, embryogenic calli were placed on maturation media containing 20 mg/L PPT. Approximately 200 putatively transgenic plantlets were obtained in hormone free media containing 40 mg/L PPT. Northern blot hybridization analysis confirmed the expression of the bar gene that was integrated into the genome of five transgenic plants. Transgenic cucumber plants were grown to maturity. Mature plants in soil showed tolerance to the commercial herbicide (Basta) of PPT at the manufacturer's suggested level (3 mL/L).

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.21-26
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• 1999

These experiments were attempted to introduce rolC gene in the Petunia hybrida cv. Titan white by Agrobacterium mediated. The maximum frequency of shoot regeneration was obtained by 60% on MS medium containing 1.0 mg/L BA, 0.1 mg/L NAA, 200 mg/L kanamycin, 500 mg/L carbenicillin, 30 g/L sucrose, and 8 g/L agar. Kanamycin-resistant calli were selected from petunia leaf discs by cocultivation with Agrobacterium suspension cultures on MS medium. The addition of AgNO$_3$ and KMnO$_4$ in the medium increased the shoot regeneration by 31.3% from leaf disc as compared with non-treated leaf disc. Among clones exhibiting kanamycin resistance, only 3 clones were confirmed by southern hybridization analysis.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.225-232
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• 2010

The effect of Protox expression site on herbicidal resistance was investigated in wild-type and transgenic rice plants imposed by peroxidizing herbicide oxyfluorfen. The transgenic rice systems involved the plastidal expression of Arabidopsis protoporphyrinogen oxidase (Protox; AP line) and the dual expression of Myxococcus xanthus Protox in chloroplasts and mitochondria (TTS line). The oxyfluorfen-treated TTS4 line showed the lower levels of cellular leakage and malonyldialdehyde and the sustained capacity of 5-aminolevulinic acid synthesis, compared to the oxyfluorfen-treated AP and wild-type lines. During oxyfluorfen action, the TTS4 line had greater herbicide resistance than the AP1 line, indicating that the dual expression of M. xanthus Protox in chloroplasts and mitochondria prevented the accumulation of photodynamic protoporphyrin IX more effectively than the expression of Arabidopsis Protox only in chloroplasts. These results suggest that the ectopic expression of Protox in mitochondria greatly contributes to the herbicidal resistance in rice plants.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.93-100
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• 2004

많은 연구들에서 hMSC를 얻기 위해 centrifugation, fluoroscence activated cell sorter(FACS), magnetic activated cell sorter(MACS)가 이용되어져 왔다. 그러나 centrifugation만을 이용한 경우 순도가 떨어지며 FACS나 MACS의 경우에는 비용, 시간이 많이 드는 단점이 있다. 따라서 이 연구에서는 antibody cocktail을 이용하여 hMSC를 좀더 쉽게 얻어내는 방법에 대해 알아보았다. 사람의 골반에서 12G의 바늘을 이용하여 골수를 흡입한 후 heparin이 들어있는 시험관에 넣고 처리과정을 시행하기 전에 냉장고에 보관하며 가능한 한 빨리 처리 과정을 실시한다. 얻은 골수에 적당량의 RosetteSep( Stemcell Technologies)을 첨가한 후 실온에서 20분간 반응시킨다. 그 후 적당량의 Ficoll-paque위에 골수와 RosetteSep의 혼합물을 섞이지 않게 올리고 원심분리를 이용하여 원하는 세포층을 얻어낸다. 이 세포층을 따로 분리한 뒤 배양한다. 배양 시 세포가 80%이상 차기 전에 계속 passage를 시행하며 배양한다. 이는 세포가 밀도가 높아져 원치 않는 세포로 분화되는 것을 막기 위함이다. 배양된 세포가 다양한 분화능력을 가지고 있는지 알아보기 위해 세 가지로 분화를 유도하였다. 적절한 배지와 적절한 환경에서 배양함으로써 얻어진 세포를 osteoblast, chondroblast, adipocyte로 분화를 유도하였다. 분화된 세포가 원하는 형질의 세포로 분화되었는지를 확인하기 위하여 osteoblast의 경우 alizarin red staining, alkaline phosphatase activity, chondroblast의 경우 toluidine blue staining, adipocyte의 경우 Oil-Red-O staining으로 염색하여 분화를 확인하였다. 분리해낸 세포는 각각 세 가지 세포로 분화가 되었으며 이는 RosetteSep이 hMSC를 성공적으로 분리해냈다는 것을 보여준다. 그러나 모든 세포가 분화를 보이지는 않았으며 따라서 hMSC의 순도를 높이기 위한 연구가 더 필요하다. RosetteSep을 이용하면 다른 방법들 보다 쉽게 hMSC를 얻을 수 있으나 기존의 방법과 순도의 측면에서 더 비교할 필요가 있다.

• Journal of Chest Surgery
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• v.31 no.2
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• pp.194-197
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• 1998

Myoepithelioma is a benign tumor composed of sheets and islands of various proportion of spindle, plasmacytoid, epitheloid, and clear cells. We are reporting of a 38-year-old woman with an extremely rare neoplasm of the trachea, myoepithelioma. The patient had an right neck mass and diagnosed presumptively as the thyroid tumor with tracheal invasion. Resection and anastomosis of the trachea with partial thyroidectomy was done. The tumor was a well circumscribed mass with solid growth pattern and composed of spindle and epitheloid cells, which were positive for S-100 protein and smooth muscle actin. In electron microscopy, a large amount of microfilaments in the cytoplasm and layers of basement membrane-like materials in the intercellular spaces were observed, which are characteristics of myoepithelioma. Patient has been well for 8 months postoperatively.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.281-288
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• 1994

한국산 거머리(Erpobdella lineate)의 전, 후 흠반을 광학현미경과 투과전자현미경을 사용하여 조직화학적 및 미세구조적 연구를 수행한 결과 다음과 같았다. 거머리 전, 후 홍안에서 관찰된 상피세포는 불규칙한 단층원주형 상피로 되어 있으며, 상피세포의 상단에는 큐티를층이 있고 측면원형질 막은 거치상을 이루면서 여러개의 desmosome이 관찰되 었다. 큐티클층은 projection eplcuticularis, amorphorous stratum 및 fibrous stratum 등 3부분으로 구분되었다. 전, 후 출반의 상피조직 사이에서 공히 a형 분비과립과 b혐 분비과립 등이 관찰되었는데, 이 세포에서 분비된 과립들은 중성점액다당류로 확인되었다. 전 흠반의 횡단면 상피조직 밑에서 많은 근육세포들조 형성된 원형의 집단들이 다수 관찰되었는데, 이는 흠반의 흡수기능과 밀접한 관계가 있었다 비교적 통근형태의 근육세포들은 세포의 원형질막 내측에 많은 근섬유 다발을 지니고 있고 그 중앙에는 cristae가 발달된 많은 수의 사립체들이 모여 있었다. 전, 후 출반의 결합조직 내에서 5종류(A, B, C, D 및 I 등)의 분비과립들이 관찰되었다. 그 중 C, D 과립은 전, 후 흡반에서 공통으로 관찰되고, A, B 과립은 전 흠반에서, E 과립은 후 흠반에서만 각각 관찰되었는데, 이들 역시 모두 중성점액다당류로 확인되었다.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.363-370
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• 1991

인체감염이 다발하는 폐흡충증의 혈청학적 진단에서 항원으로 사용하는 성충추출액은 여러단계의 질환 이행과정을 진단하는 항원으로서 문제가 있다. 이를 해결하려면 먼저 추출액내의 성분단백질의 성상을 파악할 필요가 있다. 이 연구에서는 폐흡충 성충 추출액으로 면역시킨 BALB/c mice의 비장세포와 SP2/0 형질세포종 세포를 세포융합하여 제작한 단세포군항체를 이용하여 친화성크로마토그래피로 폐흡충 성충의 구성단백질의 일부를 순수분리하고 성상을 관찰하였다. 그 결과는 다음과 같다. 1. 세포융합으로 PFCK-21, PFCK-44, PFCK-136, PFCK-189 등 4종류의 단세포군 항체를 얻었다. 그중 PFCK-21과 PFCK44는 17k Da, PFCK-136은 23, 46, 92 kDa 단백질에 반응하였고 PFCK-189는 여러종류의 단백질에 반응하였다. 2. PFCK-44 단세포군항체를 고리로 친화성 크로마토그래피를 실시하여 분리한 성분 단백질은 disc-PAGE상 4번째에 위치하고 분자량이 17 kDa로 알려진 단밸질이었다. 이 단밸질은 17 kDa의 monomer로 판단하였다. 면역조직화학염색을 실시한 결과 이 단밸질은 장관 상피세포에 반응하고 있었다. 3. PFCK-136 단세포군항체로 순수분리한 단밸질은 disc-PAGE상 1번 단밸질(440 kDa)이었으며 환원성 SDS-PAGE에서는 23 kDa 단밸질이었다. 면역조직화학염색으로 이 단세포군항체는 충란내 세포에 강하게 반응하고 있었다.