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        검색결과 103

        21.
        2013.09 구독 인증기관 무료, 개인회원 유료
        Transgenic chickens have been spotlighted as an highly potent bioreactor for their fecundity, short generation time, and eggs associated with mass production of protein. In this study, we generated transgenic chickens exhibiting oviduct specific expression of human growth hormone fused to human transferrin for oral administration. Gene of the modified growth hormone located at downstream ovalbumin promoter (∼3.6 kb) was introduced to stage X blastodermal cell employing retrovirus vector system. Several transgenic chickens were successfully generated. However, genomic analyses showed unexpected deletion within the transgene. The modification of the transgene seemed to occur during germ cell formation because the deletion was detected only from the sperm DNA of the G0 founder animal. There was no evidence of deletion in the somatic cell DNA samples of the same chicken. Consequently, same pattern of the deletion was confirmed in both somatic and germ cells of the G1 progeny.
        4,000원
        22.
        2013.06 구독 인증기관 무료, 개인회원 유료
        AtSAGT1 encodes a salicylic acid (SA) glucosyltransferase enzyme that catalyzes the formation of SA glucoside and SA glucose ester. Here, the AtSAGT1 gene expression patterns were determined in AtSAGT1 promoter::GUS transgenic Arabidopsis plants. As a result, the factors regulating the induction of AtSAGT1 were identified as pathogen defense response, wound response, exogenous application of SA, and jasmonic acid treatment.
        4,000원
        23.
        2012.10 구독 인증기관·개인회원 무료
        An endoparasitoid wasp, Cotesia plutellae, contains a polydnavirus called C. plutellae bracovirus (CpBV) and induces various physiological alterations of parasitized host along with expressions of viral genes. Two host translation inhibitory factors (HTIFs) encoded in CpBV specifically inhibit host mRNAs at post-transcriptional level. They are expressed in late larval stage of Plutella xylostella parasitized by C. plutellae. To understand their late expression control, promoter region of an HTIF gene called CpBV15α was cloned by inverse PCR. The cloned HTIF upstream region (1,113 bp) possessed a putative JH response element (JHRE) and other promoter elements. The putative promoter region was rejoined with an open reading frame of enhanced green fluorescence protein (EGFP). When the recombinant vector construct was injected into early third instar larvae of nonparasitized P. xylostella, it was expressed in fourth larval instar at 72 h after injection, compared to relatively early expression in 24 h after injection of control construct containing a baculovirus immediate-early promoter. However, recombinant EGFP construct lost the late expression pattern when its promoter region was incomplete by truncating JHRE region. PYR application inhibited EGFP expression of the recombinant construct, but gave little influence on truncated constructs. Interestingly, when the complete promoter construct was injected to pupal stage, its late expression pattern was lost and showed early expression pattern. However, an addition of PYR to pupae, which had been injected with the complete promoter construct, inhibited the reporter gene expression. These results suggest that late expression of a HTIF (CpBV15α) is controlled by its promoter, which is sensitive to host JH titer.
        24.
        2012.09 구독 인증기관 무료, 개인회원 유료
        The shortage of human organs for transplantation has induced the research on the possibility of using animal as porcine. However, pig to human transplantation as known as xeno-transplantation has major problem as immunorejection. Recently, the solutions of pig to human xenotransplantation are commonly mentioned as having a genetically modification which include alpha 1, 3 galatosyl transferase knockout (GTKO) and immune-suppressing gene transgenic model. Unfortunately, the expression level of transgenic gene is very low activity. Therefore, development of gene overexpression system is the most urgent issue. Also, the tissue specific overexpression system is very important. Because most blood vessels are endothelial cells, establishment of the endothelial-specific promoter is attractive candidates for the introduction of suppressing immunorejection. In this study, we focus the ICAM2 promoter which has endothelial-specific regulatory region. To detect the regulatory region of ICAM2 promoter, we cloned 3.7 kb size mini-pig ICAM2 promoter. We conduct serial deletion of 5' flanking region of mini-pig ICAM2 promoter then selected promoter size as 1 kb, 1.5 kb, 2 kb, 2.5 kb, and 3 kb. To analyze promoter activity, luciferase assay system was conducted among these vectors and compare endothelial activity with epithelial cells. The reporter gene assay revealed that ICAM2 promoter has critical activity in endothelial cells (CPAE) and 1 kb size of ICAM2 promoter activity was significantly increased. Taken together, our studies suggest that mini-pig ICMA2 promoter is endothelial cell specific overexpression promoter and among above all size of promoters, 1 kb size promoter is optimal candidate to overcome the vascular immunorejection in pig to human xenotransplantation.
        4,000원
        25.
        2012.06 구독 인증기관·개인회원 무료
        20ɑ-hydroxysteroid dehydrogenase (20ɑ-HSD) enzyme converts progesterone into biological inactive steroid, thus playing a key role in the termination of pregnancy or estrus cycle and allowing parturition and ovulation to occur in most mammalian animals. However, function and regulation of this enzyme has not known well in primate reproductive physiology. We previously demonstrated the expression level and localization of the 20α-HSD in the reproductive tissues of macaque monkeys of pre-ovulation and pre-parturition period. Also, we amplified about 2005 bp 5'-flanking region from placenta genomic DNA and examined methylation pattern and promoter activity. In present study, we focus on the analysis of molecular characterization of the promoter region by using reporter assay systems. We constructed of deleted mutants (— 890 bp; HSF-2), (— 513 bp; XFD), (— 276 bp; Ap-1) and (— 72 bp; Sp-1) and each mutants were cloned into pGL3-basic vector. These deletion mutants were transfected into CHO cells and co-transfected with Sp-1 or Ap-1 transcription factor plasmids. Compared to — 890 bp and 513 bp promoter fragments alone, transcription activity increased when these constructs were co-transfected with Sp-1 and Ap-1 factor. However, for the absence Ap-1 factor binding site in 276 bp fragment activity dramatically decreased in both transfections. Next, we constructed of 306 bp fragment which is including of Ap-1 binding site and nucleotides converted mutants of the Ap-1 factor binding site. In this result, 306 bp fragment's transcription activity was high as wild type. However, the mutant activity which converted Ap-1 site’s all nucleotide was significantly decreased. These findings are confirmed by gel-shift assay examining Ap-1 binding site on the 20 α-HSD gene upstream region and expression of Ap-1 factor was determined by RT-PCR and Western blot in pre-parturition period placenta and CHO-K1 cell line. Our results indicate that Ap-1 site (— 281 → — 274) (5'-TGTCTCAT-3') plays a crucial role for monkey 20 α- HSD gene transcription.
        26.
        2012.05 구독 인증기관·개인회원 무료
        An endoparasitoid wasp, Cotesia plutellae parasitized young larvae of diamondback moth, Plutella xylostella. Parasitized larvae exhibit sign ificant immunosuppression and fail to metamorphose to pupal stage. Especially, during last instar of parasitized P.xylostella, massive nutrients divert from host to wasp development. CpBV15α ,a host translation inhibitory factors encoded in C. Plutella bracovirus(CpBV), plays a crucial role in suppressing host usage of amino acids. Its promoter analysis shows that CpBV15α specifically inhibit host development in late larval period. To understand its inhibitory target, its specific expression was performed in non-parasitized P. xylostella by in vivo transient expression technique. Total plasma proteins were analyzed by 2D gel electrophoresis and determined target genes inhibited by CpBV15α. Immunoprecipation of cellular extract with CpBV15α antibody captured eIF2B. CpBV15α shares sequence homology with eIF5, especially at its eIF2B-binding region. Our results suggest that CpBV15α may sequester eIF2B, which result in malfunctioning of eIF2 cycling to form a translation initiation complex.
        27.
        2012.02 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 물리, 화학, 생물적 처리과정 중 서로 다른 용량의 퇴비가 농촌쓰레기처리공정에서의 수치를 검측하였다. 그 결과, 농촌쓰레기의 5‰ EM 해결시, 지렁이의 생장에 유익했고 34일이 지나면 예비 비료화가 되고, 35일에는 벌레가 자랐다. 5‰ EM 처리 샘플의 C/N비, NH4+-N농도, 활성화 우레아제, 섬유소와 삭카라아제는 다른 그룹보다 낮았지만 NO3-N 농도는 다른 그룹보다 선명하게 높았다.
        4,000원
        28.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        히어리 대량급속증식법의 기초를 마련하기 위해, 발 근촉진제의 처리가 히어리 삽수의 발근에 미치는 영향을 살펴보았다. 삽수는 6~8년생 실생 히어리로 부터 채취 하였으며, 발근촉진제로는 IBA용액, 루톤분의제 등을 이용하였다. 1차년도의 실험의 결과, 3월 20일 숙지삽 목에서는 발근촉진제의 효과가 없었다. 6월 20일 녹지 삽의 경우에는 IBA 100mg·L−1 용액 24시간 침적처리구 에서 발근력이 가장 좋았다. 특히, 경시조사결과 IBA100 mg·L−1 24시간 침적처리구에서는 발근속도가 현저 하게 빨라졌다. 2차년도의 실험의 결과에서는 IBA 200 mg·L−1 용액 24시간 침적처리구에서는 삽목 30일 만에 거의 모든 개체가 발근(97.8%)하였으며 발근수나 발근장도 타처리구에 비해 월등히 좋았다.
        3,000원
        29.
        2011.10 구독 인증기관·개인회원 무료
        Porcine beta casein promoter를 이용하여 형질전환 동물에서 유선특이적으로 목적 단 백질을 발현시킬 수 있는 pPBC 벡터를 구축하였으며 이 벡터를 이용하여 보다 높은 농 도의 목적 단백질을 발현 시킬 수 있도록 pPBC 벡터 개량을 시도하였다. pPBC 벡터의 5'arm 부위를 5428 bp, 4419 bp, 3378 bp의 길이로 잘라 서로 다른 크기의 5’arm을 갖 게 하였으며 5’arm의 5’ 쪽으로 CMV enhancer를 삽입하였다. 또한, porcine beta casein promoter 조절 하에 hGH(human growth hormone) 유전자를 발현하도록 하는 벡터를 구 축한 후 세포주 및 형질전환 마우스에서 발현 양상을 확인하였다. 개량된 pPBC 벡터를 이용하여 mouse mammary gland epithelial cell line HC11에서 luciferase assay를 통해 각각의 벡터에 대한 활성을 확인한 결과, 5’arm 길이가 가장 짧고 CMV enhancer가 삽입 된 CMV-pPBC p-3378 벡터에서 활성이 가장 높게 나타났다. 이 벡터를 이용하여 hGH 유전자와 mRNA를 안정화시켜 유전자의 발현을 증가시킨다고 알려진 woodchuch hepatitis virus post-transcriptional regulator element (WPRE)를 함께 삽입하여 CMV-pPBC p-3378-hGH-WPRE 벡터를 구축하였다. 이 벡터로 transgenic mice를 생산하여 유선을 포함한 여러 조직으로부터 hGH의 발현을 RT-PCR 방법을 확인하였다. 그 결과 liver와 lung에서는 아주 약하게 hGH가 발현을 하였으나 유선 조직에서 hGH가 가장 많이 발현 하는 것을 볼 수 있었다. 형질전환 마우스 유즙 내의 hGH 발현을 western과 ELISA를 이 용하여 확인한 결과, 유즙 내에는 약 22 kDa의 hGH가 존재 하였으며 ml 당 최고 50 100 ug의 농도로 hGH를 포함하고 있었다. 이러한 결과들은 개량한 pPBC 벡터가 유선특 이적인 발현을 하며, 유선 세포주에서는 높은 활성을 나타냈지만 형질전환 마우스의 유 즙에서는 개량전의 벡터 보다 낮은 수준의 목적 단백질을 생산하여 서로 상이한 결과를 나타내었다. 따라서 앞으로도 유선특이적 발현 벡터인 pPBC 벡터의 개량 연구를 계속 진행할 것이다.
        31.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        Ceriporiopsis subvermispora is a unique white rot fungus degrading plant cell wall lignin without severe loss of cellulose. Recombinant plasmids containing homologous gene expression signals fused to the coding sequence of Escherichia coli hph which encodes for hygromycin phosphotransferase were introduced in protoplasts of wild type C. subvermispora using PEG/CaCl2 protocol. A number of hygromycin B resistant strains were isolated on a screening plate containing 100㎍/ml of hygromycin B: whereas, no colonies were observed when protoplasts were treated with no DNA as a negative control. It was demonstrated that most of the isolates lost their drug resistance during successive cultivations in the presence of the same concentration of hygromycin B, but some of the isolates showed stable drug resistance after five times repeated screening. They did not lose the drug resistance even after the cultivation in the absence of hygromycin B and incorporation of the hph sequence was confirmed by specific amplification of the target sequence in PCR experiments and Southern hybridization analysis. The stable transformation system will make it possible to do molecular genetic analysis, as well as breeding of genetically modified strains, in C. subvermispora. Moreover, it was demonstrated that recombinant constructs with truncated promoter showed reduced number of the drug resistant isolates on the first screening plate, in response with the length of the remaining promoter sequence. These findings indicated that unstable drug resistance observed in these isolates should originate from transient expression of the introducing marker genes, and that a promoter assay system has been developed for the first time in basidiomycete. This system is practically not affected by the positional effect of the integrated recombinant gene in the host chromosome.
        36.
        2010.05 구독 인증기관·개인회원 무료
        For stable germline transformation, the promoter of B. mori cytoplasmic actin gene (BmA3) was used to ubiquitous expression of transgenes. Except for BmA3 promoter, promoters used to regulate gene expressionin all tissues and developmental stages of B. mori were not nearly developed. To identify more powerful promoter than previously reported BmA3 promoter (Mange et al., 1997), we introduced a new dot blot hybridization method, and isolated nine clones that show stronger dot signal compared to the control, BmA3by this method. Among these 9 clones, we focused on one clone which has high amino acid homology (94%) with heat shock protein 70 gene of Trichoplusia ni. This resulting positive clone, named bHsp70 (B. mori heat shock protein 70) was ubiquitiously expressed in tissues and developmental stage of fifth instar B. mori larvae,and stimulated bythermal and ER stress. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-1003/+147) in the 5'-flanking region of bHsp70 gene that has 264-fold more intensive promoter activity than BmA3 promoter. Moreover, transcription activity of bHsp70 promoter under heat shock condition (42 ℃, 4 hr) was increased over 2-fold than normal condition. Therefore, we suggest that bHsp70 promoter may be used more effective candidate for transgene expression in B. mori.
        38.
        2008.10 구독 인증기관·개인회원 무료
        Recently Transgenesis was achieved in Bombix mori. For stable and effective transgenesis in B.mori, B.mori cytoplasmic actin gene (BmA3) promoter was used to expression of marker gene, the green fluorescent protein(GFP). Green fluorescent protein expression for selection of transformants was visible in all larval, pupal, and adult tissues but, unexpectdly, was not detectable in embryos. So, it spend times and money on rearing of silkworm. Furthermore, the BmA3 promoter is predominantly active in the midgut, which makes it difficult to reliably identify transformants since autofluorescence of many insect foods can mask low-level fluorescence and only allows the detection of strongly expressing individuals with potentially multiple insertions. Therefore, we need more intensely promoter than BmA3 promoter for selected by expression of GFP in embryos and selected by reliable expression of GFP in larvae. We performed dot blot hybridization to develop strong promoter. Nine differentially expressed clones were isolated and we focused one clone of them which has high similarity with heat shock protein 70 gene from D.melanogaster. We named it as bHSP70 (Bombyx mori heat shock protein 70). Expression from the hsp70 promoter was strong and heat shock-dependent. And Drosophila hsp70 promoter appears useful for regulating expression of Exogenous DNA. So, we analyzed transcriptional activity of promoter with bHSP70 gene by using dual luciferase assay system. bHSP70 promoter has about 264 folds more intensely than BmA3 promoter. Also, when bHSP70 promoter treated heat shock(42℃), transcriptional activity incresed 2 times more than normal condition. Therefore, we suggest that bHSP70 promoter is more effective candidate for stable transformation and selection of transformants.
        39.
        2008.06 구독 인증기관 무료, 개인회원 유료
        Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.
        4,000원
        40.
        2008.03 구독 인증기관 무료, 개인회원 유료
        DNA 메틸화는 조직특이적인 유전자 조절에 관여하고, 정상적인 배 발달에 필수적이다. POU5F1은 octamer-binding transcription factor 4 (Oct-4)를 encode하며, 초기 분화에 중요한 전사인자이다. 본 실험에서 소의 Oct-4가 조직특이적이고 발달의존적인 epigenetic 표지 인지를 검토하고자, 착상 전 수정란에서 Oct-4 전사산물과 상류 promoter 영역의 CpGs의 메틸화를 조사하였다. Oct-4 전사산물은 정자 그리고 2-cell에서 8-cell 수정란까지 낮은 수준으로 존재하지만, 상실배와 배반포에서 높게 검출되었다. 이러한 결과는 배 발달 과정의 상실배 단계에서 Oct-4의 de novo 발현이 시작됨을 의미한다. Oct-4 상류 promoter 영역에는 메틸화 가변 영역 (tissue-dependent differentially methylated region, T-DMR)이 존재한다. Oct-4 메틸화 가변 영역의 메틸화 상태는 정자, 성체 체조직과 난자에서 서로 다르고, 수정란으로부터 배반포 단계까지 변화하였는데, 이는 착상 전 초기 배 발달 과정에 active 메틸화와 탈메틸화가 일어남을 의미한다. 이상의 결과, Oct-4 유전자 상류 promoter 영역은 DNA 메틸화의 타깃이고, 그 메틸화 상태는 소 수정란 발달 동안에 다양하게 변화한다.
        4,000원
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