결과 내 재검색





        검색결과 26

        2020.03 구독 인증기관 무료, 개인회원 유료
        Oral lichen planus (OLP) is a chronic inflammatory disease observed in approximately 0.5–2.2% of the population, and it is recognized as a premalignant lesion that can progress into oral squamous cell carcinoma (OSCC). The rate of malignant transformation is approximately 1.09–2.3%, and the risk factors for malignant transformation are age, female, erosive type, and tongue site location. Malignant transformation of OLP is likely related to the low frequency of apoptotic phenomena. Therefore, apoptosis-related genetic factors, like p53, BCL-2, and BAX are reviewed. Increased p53 expression and altered expression of BCL-2 and BAX were observed in OLP patients, and the malignant transformation rate in these patients was relatively higher. The involvement of microRNA (miRNA) in the malignant transformation of OLP is also reviewed. Because autophagy is involved in cell survival and death through the regulation of various cellular processes, autophagy-related genetic factors may function as factors for malignant transformation. In OLP, decreased levels of ATG9B mRNA and a higher expression of IGF1 were observed, suggesting a reduction in cell death and autophagic response. Activated IGF1-PI3K/AKT/mTor cascade may play an important role in a signaling pathway related to the malignant transformation of OLP to OSCC. Recent research has shown that miRNAs, such as miR-199 and miR-122, activate the cascade, increasing the prosurvival and proproliferative signals.
        2014.10 구독 인증기관·개인회원 무료
        Agrobacterium tumefaciens causes crown gall disease by transferring its DNA into host plants. Although Agrobacterium can be popularly used for genetic engineering, above-ground insect infestation in Agrobacterium gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect whitefly infestation and a chemical trigger, benzothiadiazole (BTH), for 7 days, and these exposed plants were inoculated with Agrobacterium. We evaluated how whitefly infestation manipulated gall disease by Agrobacterium in planta and in vitro. Insect whitefly infested plants exhibited at least a 2-fold reduction in gall formation on both stem and crown root. Silencing isochorismate synthase 1 (ICS1), required for salicylic acid synthesis, compromised gall formation, indicating an involvement of salicylic acid in whitefly-derived plant defense against Agrobacterium. Endogenous salicylic acid content was augmented in whitefly-infested plants by Agrobacterium inoculation. However, infestation with whitefly did not alter Agrobacterium root colonization but reduced expression levels of genes involved in Agrobacterium virulence and transformation efficiency. Above-ground whitefly infestation therefore elicits systemic responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand a general principle in multitrophic interactions in nature.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        포장에서 생육된 잔디 포복경을 이용한 Agrobacterium 형질전환에 있어서 큰 제한인자였던 곰팡이 오염을 제거할목적으로 포복경 조직에 대한 새로운 살균법을 개발하고자하였다. 여러 가지 살균방법 중에서 30% NaOCl로 15분간처리한 다음 0.1% HgCl2로 25분간 처리 했을 때 포복경절편체의 생존율이 높았으며, 0.1% HgCl2로 처리시 800mbar의 진공처리를 5분간 실시했을 때 가장 효과적이었다.또한 Agrobacterium과 공동배양 시 2.5 mg/l의 amphotericinB를 첨가해 준 배지에서 배양했을 때 가장 높은 생존율을나타내었다. AmB의 처리는 Agrobacterium의 생장에 영향을 미치지 않았다. 또한 살균된 포복경으로 부터 신초의재분화에도 영향을 미치지 않았으며 곰팡이 오염만을 효율적으로 억제하는 것으로 나타났다. 이러한 결과는 포장에서 대량으로 생육시킨 잔디 포복경을 이용한 Agrobacterium형질전환 시 그 효율을 증가시키는데 큰 기여를 할 것으로추측된다.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Trichoderma harzianum 균사체를 Al2O3 입자와 마찰시킴으로써 Agrobacterium을 이용한 형질전환 에 효과적으로 이용할 수 있었다. Hygromycin 저항성 균사체 출현을 비교한 결과 형질전환 효율이 20% 정도로 나타났으며 대조군의 경우 형질전환균사체의 출현은 없었다. 2차례의 연속적인 항생제배지에서 선발을 거친 형질전환균사체들은 PCR에 의하여 안정적 DNA도입이 확인되었으며 RT-PCR에 의하여 target gene의 mRNA발현을 확인할 수 있었다. 현재까지 Agrobacterium을 이용한 T. harzianum 형질 전환은 보고된 바 없다.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Trichoderma spp.는 white biotechnology에서 이용되는 대표적인 미생물로서 이들이 강력하게 분비 생산하는 효소들은 산업적으로 매우 중요하다. 본 연구에서는 amylase, pectinase, cellobiohydrolase 및 xylanase 분비활성이 높은 것으로 밝혀진 Trichoderma sp. KACC 40541균주에 대한 Agrobacterium이용 형질전환을 수행하였으며 균주개량을 위한 효율적인 유전자도입 방법을 제시하였 다. 특히 형질전환을 위하여서는 균사체에 대한 적정 농도의 NaOH처리가 매우 효과적임을 보여주었다.
        2013.07 서비스 종료(열람 제한)
        Abscission is an important developmental process used to shed organs such as leaves, flowers and fruits. Despite the detailed characterization of growth dynamics and hormonal balance during the early steps of fruit development, the molecular aspects remain unclear. Abscission of young fruit occurs by separation of cells in anatomically distinct regions between the pedicel and junction. Differences of gene expression between central pedicel and lateral pedicel were investigated by NGS. Partial cDNAs from 15 clones from both the central pedicel and lateral pedicel were selected for nucleotide sequence determination and homology searches, and 12 clones were subsequently selected for further analysis. In preliminary series of Real Time PCR analysis, 9 genes were confirmed as showing a higher expression level in lateral pedicel than in central pedicel. Many of these genes are expressed in a central or lateral pedicel in specific manner, and the expression profiles of the representative genes were confirmed. To clarify the mechanism of MdIAA14 transcription factor gene underlying abscission zone development, we are investigating the expression patterns between central and lateral pedicels in different apple cultivar using real-time PCR and constructing the vector for transformation into apple.
        2012.07 서비스 종료(열람 제한)
        In order to improve rice dough functionality, we cloned 4 kinds of high-molecular-weight glutenin subunit (HMW-GS) genes from bread wheat, ‘Jokyeong’. Among them, we first examined Dx5 gene to generate marker-free transgenic rice for advanced quality processing of bread and noodles. The GluB1 promoter was inserted into binary vector for seed specific expression of the Dx5 gene. Two expression cassettes comprised of separate DNA fragments containing only the high-molecular-weight glutein subunit (HMW-GS) protein (Dx5) and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately to tumefaciens EHA105 strain for co-infection. Each EHA105 strain harboring Dx5 or HPTII was infected to rice calli at 3: 1 ratio of Dx5 and HPTII, respectively. Then among 66 hygromycin-resistant transformants, we obtained two transgenic lines inserted both with Dx5 and HPTII gene to rice genome. We reconfirmed integration of the Dx5 and HPTII genes into the rice genome by Southern blot analysis. Wheat Dx5 transcriptsin rice seeds was examined with semi-quantitative RT-PCR. Finally, the marker-free plants containing only Dx5 gene were successfully screened at T1 generation. This result also provides that co-infection system with two expression cassettes could be efficient strategy to generate marker-free transgenic rice plants.
        2012.07 서비스 종료(열람 제한)
        Korean soybean variety Kwangan was transformed with ORE7 gene using highly efficient soybean transformation system. The gene is known to exhibit a delayed leaf senescence phenotype in Arabidopsis. To confirm phenotypic characterization of leaf senescence for non-transgenic (NT) and transgenic plants, we transplanted T1 transgenic lines 7, 9, 14 and 15 together with two negative controls (NT and EV) in greenhouse. As a result, line 15 showed dramatic phenotypic characterization of yield increase and senescence delay. In addition, to investigate the agriculture traits for transgenic plants with leaf senescence delaying, T2 transgenic lines and two negative controls were transplanted on GMO fields in Ochang and harvested T3 seeds (2010). Most transgenic lines showed higher total seed weigh than NT. Especially, total seed weight of line 15 was increased by about 180% and 120% compared with the NT and EV, respectively. Therefore, we carried out the second field experiments with T3 transgenic line 15 and NT in Ochang (2011). A total of 117 transgenic plants were divided into two groups, senescence delaying (64 out of 117 plants) and increased yield (53 out of 117 plants), by transcript level of ORE7 gene. Interestingly, among increased yield plants, total seed weight of each 7 plants were increased by more than 200% compared with NT.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        의학적 중요성에도 불구하고 다년생 약용식물의 하나인 황기(Astragalus membranaceus)와 관련된 분자육종 연구의 전무한 편이다. 본 연구에서는 황기의 유묘를 대상으로 agroinfiltration법을 이용한 in planta 형질전환을 시도하였다. 형광 및 염색법에 의한 GUS발현 분석에서 황기는 Agrobacterium 감염이 쉽지 않은 것으로 나타났다. 그러나 발아 후 2-3일이 결과한 유묘에 대하여 NaOH나 과산화수소를 적절히 처리
        1 2