• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.177-186
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• 2005

Xenotransplantation may help to overcome the critical shortage of human tissues and organs for human transplantation, Swine represents an ideal source of such organs owing to their anatomical and physiological similarities to human besides their plentiful supply, However, the use of organs across the species barrier may be associated with the risk of transmission of pathogens, specially porcine endogenous retroviruses (PERVs).• Although most of these potential pathogens could be eliminated by pathogen-free breeding, PERVs are not eliminated by this treatment. PERVs are integrated into the genome of all pigs and produced by normal pig cells and infect human cells. They belong to gamma retroviruses and are of three classes viruses: A, B and C. In the present study, PCR based cloning was performed with chromosomal DNA extracted from pigs from domestic pigs in Korea. Amplified PCR fragments of about 1.5 Kb, covering the partial env gene, were cloned into pCR2.l-TOPO vectors and sequenced. A total of 91 env clones were obtained from domestic pigs, Berkshire, Duroc, Landrace and Yorkshire in Korea. Phylogenetic analysis of these genes revealed the presence of only PERV class A and B in the proportion of 58 % and 42 %, respectively. Among these, 28 clones had the correct open reading frame: 18 clones in class A and 10 clones in class B. Since both these PERV classes are polytropic and have the capacity to infect human cells, our data suggest that proviral PERVs have the potential to generate infectious viruses during or after xenotransplantation in human.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.187-191
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• 2007

This study was canted out to develop cell lines overexpressing human H-transferase (HT). One of the approaches to prevent hyperacute rejection in xenotransplantation might be the expression of human HT in porcine cells. In this study, we cloned human HT gene from HepG2 cells using RT-PCR to establish HT-overexpressing vector. The full-length cDNA of human HT was inserted into the 3' end of CMV promoter for construction of the overexpression vector pRc/CMV-hHT. Using ietPEI DNA transfection reagent, the vector was introduced into porcine ear skin fibroblasts from newborn piglets. Transfected cells were selected by treatment of $300{\mu}g/ml$ G418 for 12 days. After antibiotic selection, survived colonies with approximately 5mm in diameter were picked and analysed for transgene human HT by PCR. The colonies proven to be human HT transfectants were analysed by RT-PCR to determine their expressions or human HT. In all colonies tested, human HT mRNA was detected. This result demonstrates the establishment of porcine cell lines overexpressing human HT, and these cell lines may be used for the development of transgenic pigs for xenotransplantation.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.73-79
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• 2017

Transplantation is considered to be a very useful approach to improve human welfare and to prolong life-span. Heterologous organ transplantation using pig organs which are similar to human beings and easy to make mass-production has known as one of the alternatives. To ensure potential usage of the pig organ for transplantation application, it is essentially required to generate transgenic pig modifying immuno-related genes. Previously, we reported production of heterozygous ${\alpha}1,3$-galactosyltransferase (GalT) knock-out and human membrane cofactor protein (MCP) expressing pig ($GalT^{-MCP/+}$), which is enforced for suppression of hyperacute and acute immunological rejection. In this study, we reported generation of homozygous pig ($GalT^{-MCP/-MCP}$) by crossbreeding $GalT^{-MCP/+}$ pigs. Two female founders gave birth to six of $GalT^{-MCP/-MCP}$, and seven $GalT^{-MCP/+}$ pigs. We performed quantitative real-time PCR, western blot, and flow cytometry analyses to confirm GalT and MCP expression. We showed that fibroblasts of the $GalT^{-MCP/-MCP}$ pig do not express GalT and its product Gal antigen, while efficiently express MCP. We also showed no expression of GalT, otherwise expression of MCP at heart, kidney, liver and pancreas of transgenic pig. Taken together, we suggest that the $GalT^{-MCP/-MCP}$ pig is a useful candidate to apply xenotransplantation study.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.181-187
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• 2006

In recent years the number of patients waiting for organ transplantation has greatly outpaced the supply of human organs available, which leads to a renewed interest in pig-to-human xenotransplantation as an alternative. However, one of the biggest barriers in the xenotransplantation is presence of porcine endogenous retroviruses(PERV) that can infect human cells. In this study, to present a possible solution for this problem we tried to inhibit expression of PERVs using shRNAs(short hairpin RNA) at the level of RNA synthesis and virus release. The shRNA targeting the sequence of PERV A, B type was cloned into pSIREN-RetroQ vector under the control of polymerase-III U6-RNA gene promoter. Quantitative real-time PCR was performed to detect my alterations in mRNA production of PERV A, B targeted by the shRNA in each done. Depending on the target sequence of the shRNA, the transcription of PERV was decreased to as much as 4% and the number of progeny viruses was reduced to less than 1/200,000. Transgenic pigs producing such shRNAs may result in a highly reduced PERV expression in cells and organs, which is a prerequisite for safe xenotransplantations.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.170-170
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• 2004

First of all, in vitro production (IVP) of porcine embryos is an important as initial step to improve bio-technical applications such as transgenesis and cloning for xenotransplantation. In recent years, considerable progress has been achieved in the IVP embryos using advanced methods for in vitro maturation (IVM) and fertilization (IVF). (omitted)

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.122-123
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.122-123
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.109-109
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• 2003

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.110-110
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• 2003

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.343-346
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• 2000

Transgenic animals are very useful for scientific, pharmaceutical, and agricultural purposes. In livestock, transgenic technology has been used forth genetic alteration of farm animals, the production of human proteins inlarge quantities in the milk of transgenic farm animals (Clark et al., 1989; Ebert et al., 1991; Kimpenfort et al., 1991; Wall et al., 1991; Kimpenfort et al., Well et al,m 1991; Hill et al., 1992; Velander et al., 1994; Chen et al.), and the generation of animals with organs suitable for xenotransplantation (Pinkert, 1994; Chen et al., 1999). (omitted)