• BMB Reports
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• 제38권1호
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• Journal of Plant Biotechnology
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• 제37권3호
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• pp.275-282
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• 2010

고등식물의 엽록체 형질전환은 핵 형질전환에서 기대 할 수 없는 여러 가지 이점을 가진다. 외래 단백질의 발현율을 획기적으로 높일 수 있고, 여러 유전자를 동시에 발현시킬 수 있으며, 상동재조합에 의한 부위-특이적 유전자 삽입으로 인해 유전자 침묵 및 위치효과가 없다. 더욱이, 대부분 작물은 화분을 통한 도입된 유전자의 전이가 불가능한 모계 유전을 하기 때문에 엽록체 형질전환은 환경 친화적이다. 엽록체 형질전환 시스템은 핵 형질 전환과 달리 작물에서의 성공에 제한적이었으나 지난 10년 동안 이런 한계가 극복되어 콩, 당근, 상추 및 유채 등의 작물에서도 성공하게 되었다. 그러므로 이제 작물의 엽록체 형질전환은 농업적 형질의 개선뿐 만 아니라, 고부가가치 백신과 의료용 단백질 생산을 통한 의약품 산업의 성장에 활용될 수 있을 것이다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.77-77
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• 2003

Chimeric animals are referred to as an organism composed of tissues derived from more than one species. In order to examine if a pluripotency of embryonic stem cells can cross the limitation of a species, we tried to establish human-mouse chimeric animals. Human embryonic stem cells were genetically modified to express eGFP using eukaryonic expression vector pcDNA 3.1 (In Vitrogene) for an easy identification. After selection with neomycin, approximately 15 cells were implanted into mouse blastocoele cavity. Ten chimeric blastocysts were transferred to one of the uterine horn of 2.5 days pesudopregnent ICR female. Out of 272 blastocysts transferred to pseudopregnant recipients 20 live newborn were obtained after 20 days. When newborn were obtained, pups were quickly removed immersed into 4% PFA. By histological examination using fluorescent microscope, green fluorescence was observed from the liver, heart, and spleen in newborn mice. Three weeks after born, presence of eGFP sequence within mouse genome (tail and kidney) was reconfirmed by PCR. eGFP sequence was amplified from the progenies of the animal suggesting a genetic transmission of the transgene. These chimeric mice having human cells at the beginning of development, are expected to recognize human cells as “self”, therefore, human cells or tissues will be able to escape the immunological surveillance of the host if grafted into the animal. These animals will serve as a good model system for studying the graft rejection in tissue transplantation and the potential of the cells to work well in many human disease.

• International Journal of Industrial Entomology and Biomaterials
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• 제24권2호
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• pp.49-55
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• 2012

We previously isolated 9 clones that show stronger signal compared to B. mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid homology with elongation factor ${\alpha}$ gene of B. mori. This clone, named $bEF1{\alpha}$ (B. mori elongation factor ${\alpha}$) was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-702/+38) in the 5'-flanking region of $bEF1{\alpha}$ gene, which has about 20 fold more intensive promoter activity than BmA3 promoter. Moreover, the $bEF1{\alpha}$ promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that $bEF1{\alpha}$ promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

• 한국수정란이식학회지
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• 제15권2호
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• pp.157-165
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• 2000

The efficiency of transgenic livestock production could be improved by early screening of transgene-integration and sexing of embryos at preimplantational stages before trasferring them into recipients. We examined the effciency of multiplex PCR analysis for the simultaneous confirmation of the trasgene and sex during the preimplantational development of bovine embryos and the possibility of green fluorescent protein(GFP) gene as a non-invasive marker for the early screening of transgenic embryos. The GFP gene was microinjected into the male pronuclei of bovine zygotes produced in vitro. The injected zygotes were co-cultured in TCM-199 containing 10% FCS with boving oviductal epithelial cells in a 5% CO2 incubator. Seventeen(13.0%) out of 136 gene-injected bovine zygotes developed by multiplex PCR analysis and the expression of GFP was detected by observing green fluorescence in embryos under a fluorescent microscope. Eight(67%) of 12 embryos at 2-cell to blastocyst stage were positive in the PCR analysis, but only two(11.8%) of 17 blastocysts expressed the GFP gene. Their sex was determined as 7 female and 5 male embryos by the PCR analysis. The results indicate that the screening of GFP gene and sex in bovine embryos by PCR analysis and fluorescence detection could be a promisible method for the preselection of transgenic embryos.

• Journal of Plant Biotechnology
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• 제43권2호
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• pp.223-230
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• 2016

아스코르빈산(ascorbic acid, AsA)는 강력한 항산화 물질 및 환원제로서 식물에서 산화형 AsA인 dehydroascorbate(DHA)를 활성형인 환원형 AsA로 변환시키는 효소인 dehydroascorbate reductase (DHAR)에 의해 생성된다. 선행연구의 결과로서, 본 연구팀은 참깨의 모상근에서 분리한 DHAR 유전자를 이용하여 항시 발현하는 CaMV 35S 프로모터와 괴경 특이적으로 발현하는 patatin 프로모터의 조절하에 과발현 시킨 형질전환 감자를 개발하였다. 형질전환 감자 식물체들은 비형질전환체 보다 증가된 DHAR 활성과 AsA 함량을 보인 바 있다. 본 연구에서는 단백질체 분석을 통해서 형질전환 감자 식물체에서 DHAR 과발현에 의해 조절되는 단백질들을 조사하였다. 단백질체 분석의 결과로서, 형질전환 감자에서 도입된 DHAR 단백질과 다양한 항산화 관련 단백질들이 식물 생장시기 동안 증가 하였다. 본 연구의 결과로서, 도입된 유전자인 DHAR이 항산화 단백질들의 발현 증가를 통해 형질전환 식물체의 스트레스 내성 기작을 향상 시킬 수 있을 것으로 생각된다.

• BMB Reports
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• 제44권5호
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• pp.298-305
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• 2011

Most intracellular reactive oxygen species (ROS), especially superoxide anion ($O_2^{{\bullet}_-}$) that is converted from oxygen, are overproduced by excessive electron leakage from the mitochondrial respiratory chain. Intracellular oxidative stress that damages cellular components can contribute to lifestyle-related diseases such as diabetes and arteriosclerosis, and age-related diseases such as cancer and neuronal degenerative diseases. We have previously demonstrated that the excessive mitochondrial $O_2^{{\bullet}_-}$ production caused by SDHC mutations (G71E in C. elegans, I71E in Drosophila and V69E in mouse) results in premature death in C. elegans and Drosophila, cancer in mouse embryonic fibroblast cells and infertility in transgenic mice. SDHC is a subunit of mitochondrial complex II. In humans, it has been reported that mutations in SDHB, SDHC or SDHD often result in inherited head and neck paragangliomas (PGLs). Recently, we established Tet-mev-1 conditional transgenic mice using our uniquely developed Tet-On/Off system, which equilibrates transgene expression to endogenous levels. These mice experienced mitochondrial respiratory chain dysfunction that resulted in $O_2^{{\bullet}_-}$ overproduction. The mitochondrial oxidative stress caused excessive apoptosis leading to low birth weight and growth retardation in the neonatal developmental phase in Tet-mev-1 mice. Here, we briefly describe the relationships between mitochondrial $O_2^{{\bullet}_-}$ and aging phenomena in mev-1 animal models

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.27-32
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• 2004

Using MLV (murine leukemia virus)-based retrovirus vectors encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein), we tried to make transgenic chickens carrying the transferred genes in their chromosomes. Twenty one days after virus injection beneath the blastoderms of unincubated chicken embryos (stage Ⅹ, at laying), DNA isolated from the hatched chicks were analyzed by PCR with two sets of primers specific for EGFP (enhanced green fluorescence protein) gene or $Neo^R$ (E. coli neomycin resistant) gene. Among sixty-seven embryos injected with retrovirus, four of them were identified to carry the EGFP genes in their genomes. Remarkably, one transgenic chick showed presence of the retrovirus vector sequences in all organs differentiated from one of endoderm, mesoderm, and ectoderm. Expression of EGFP gene was not detected, however, the stable germ line transmission of transgene was verified in spermatozoa from the founder chicken and 50% of $F_1$ progenies.

• BMB Reports
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• 제46권8호
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• pp.404-409
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• 2013

Extracellular superoxide dismutase (EC-SOD) is a metallo-protein and functions as an antioxidant enzyme. In this study, we used lentiviral vectors to generate transgenic chickens that express the human EC-SOD gene. The recombinant lentiviruses were injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. Of 158 injected embryos, 16 chicks (G0) hatched and were screened for the hEC-SOD by PCR. Only 1 chick was identified as a transgenic bird containing the transgene in its germline. This founder (G0) bird was mated with wild-type hens to produce transgenic progeny, and 2 transgenic chicks (G1) were produced. In the generated transgenic hens (G2), the hEC-SOD protein was expressed in the egg white and showed antioxidant activity. These results highlight the potential of the chicken for production of biologically active proteins in egg white.

• Reproductive and Developmental Biology
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• 제28권1호
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• pp.71-76
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• 2004

Gene delivery is one of the keen interests in animal industry as well as research on gene functions. Some of the in vivo gene delivery techniques have been successively used in various tissues for the gene therapy and transgenesis. Despite intensive efforts, it still remains to overcome problems of limited local and regional administration and low transgene expression. To improve the efficiency of gene delivery, a new procedure was tested. We injected exogenous DNA containing LacZ into the female or male gonads and then pulsed electric field. Electroporated gonads showed positive X-gal staining in many seminiferous tubules of the porcine fetal gonads. Exogenously introduced LacZ genes were also expressed in female porcine gonad. In addition, we demonstrated efficient gene delivery in gonad of adult mouse. Furthermore, we succeed to generate genetically modified germline cells showing GFP and positive X-gal signals. The results suggest that the newly developed gene delivery is an effective way of in vivo transfection in mammals. The developed gene delivery procedure should be useful in producing transgenic animals when combined with primary cell culture and nuclear transplantation.