• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2007.10a
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• pp.566-566
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• 2007

• Korean Journal of Agricultural Science
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• v.33 no.1
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• pp.35-41
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• 2006

This study was conducted to investigate the developmental ability of interspecies cloned embryos after nuclear transfer of goat fetal fibroblast cells into porcien oocytes. Recipient porcine and goat oocytes were obtained from slaughterhouse and matured in vitro according to established protocols. Enucleation was accomplished by aspirating the first polar body and cytoplasm and a single donor cell was individually microinjected into vitelline space of the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3M mannitol fusion medium. After electro-fusion, interspecies reconstituted embryos were cultured in PZM-3 for 7 days. In porcine interspecies nuclear transfer with goat fetal fibroblast cells, the cleavage rate of reconstituted embryos were 58.9% which was no significant different from that in porcine nuclear transfer embryos (67.4%). However, the developmental rate into blastocyst stage was 5.4% in interspecies nuclear transfer which was significantly lower than that in porcine intraspecies nuclear transfer (13.6%). When the developmental ability of porcine interspecies nuclear transfer with goat cells was compared with goat intraspecies nuclear transfer, the cleavage rate of embryos were 59.2% and the developmental rate into morular and blastocyst stage was 13.6% in interspecies nuclear transfer which were significantly lower than those in intraspecies nuclear transfer embryos. This result indicated that porcine interspecies nuclear transfer with goat fetal fibroblast cells showed the developmental potential in vitro with lower cleavage and developmental rate compared with intraspecies nuclear transfer.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.07a
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• pp.38-38
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• 2005

• Korean Journal of Animal Reproduction
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• v.27 no.4
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• pp.281-285
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• 2003

This study was carried out to find out the changes on serum concentrations of estradiol-17$\beta$, progesterone in primiparous Duroc, Landrace and Yorkshire sows weaned at 7 or 21 days. Also, we compared the litter size at birth and weaning among the breeds weaned after lactation for 7 or 21 days. The estradiol-17$\beta$ concentrations among the breeds were 6.9∼8.8 pg/ml and 6.4∼8.8 pg/ml after lactation for 7 or 21 days, respectively. The progesterone concentrations ranged from 0.3 ng/ml to 1.6 ng/ml. Duroc sow showed higher progesterone concentration compared with Landrace and Yorkshire sows weaned after lactation for 7 or 21 days. Also, we found out that litter size at birth and weaning, respectively, did not show any differences between day 7 and day 21 of lactation. From the facts mentioned above, it was suggested that very early weaning systems could work with no apparent adverse effect on prolificacy.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.117-121
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• 2008

Our previous study showed that transgenic (TG) pigs harboring human EPO (hEPO) gene have been shown to have reproductive disorders, including low pregnancy rates, irregular estrus cycle and low little size. To investigate these reasons, we assessed estrus behavior (standing response) and plasma $17{\beta}$-estradiol ($E_2$) level, which partly reflect reproductive function, during the estrus cycles after synchronization and superovulation by hormone treatments. Then, we analysed blood composition and expression of hEPO gene in TG pigs. Pigs were injected with PG600. After 10 days, pigs were fed with Regumate porcine for 6 days. Blood samples were collected from jugular vein. Analysis of blood composition and $E_2$ level were measured by Hemavet 950 and $E_2$ ELISA kit, respectively. And, the expression of hEPO gene in reproductive organs was quantitated by real-time RT-PCR. The percentage of estrus behavior in TG was significantly decreased. Hematocrit (HCT), hemoglobin (Hb) concentration and red blood cell (RBC) number were significantly higher in TG than wild type (WT). On the other hand, high expression of hEPO gene in TG was observed in the mammary gland as well as in the uterus. Moreover, plasma $E_2$ level was significantly higher in TG than WT. These results suggest that nonspecific expression of hEPO gene in the other organs of TG may affect blood composition and plasma $E_2$ level, thereby causing reproductive disorders.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.56-56
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• 2001

The exogenous gene transfer by intracytoplasmic sperm injection (ICSI) procedure has been recently used to produce transgenic mice and pigs. Sperm-mediated DNA transfer has the potential to markedly simplify the generation of transgenic animals. This method may serve as an alternative to the pronucleus injection of DNA for the production of transgenic pigs. Therefore, in this study, we investigated the expression of transgene after co-injection of spermatozoon or sperm head with green fluorescent protein (GFP) gene into in vitro matured porcine oocytes. Spermatozoon and sperm head, that was obtained by sonication, were treated with 0.03% Triton X-100 to remove the membrane. They were preincubated with linearized pEGFP-N1 for 1 min, and then embryos cultured NCSU23 medium for 2.5 days after co-injected of sperm and DNA. We monitored expression of GFP in embryos under epifluorescent microscope. The remove of sperm membrane did not alter the developmental competence of embryos after ICSI. At 7 days following injection, the rates of blastocysts following injection of intact sperm (15.0%), and of sperm with disrupted membrane (14.2%) were higher than that following IVF (10.0%). Porcine oocytes injected with sperm which co-cultured with DNA concentration of 1, 0.1, and 0.01 ng were 60, 65.7 and 75% and 18.5, 37.4 and 22.2% for rates of cleavage and GFP expression, respectively. In vitro matured porcine oocytes injected with sperm and isolated sperm head resulted in 69 and 59.7% of cleavage rates, respectively The rates of embryo GFP expressed did not significantly different between sperm (20.4%) and sperm head (20.0%) injection. The transgenic embryos with the clusters of positive blastomeres were observed under fluorescent microscope. Most of embryos expressed GFP gene showed mosaicism. They showed GFP expression at 1/4, 2/4 and 3/4 of blastomeres at the 4-cell stage. Among these 4-cell embryos, the expression rate of 1/4 blastomere group (54.6%) was higher than the other groups (15.3-30.7%). These results indicate that membrane disrupted sperm could attach with exogenous DNA, and that this procedure may be useful to introduce foreign gene into porcine oocytes. Therefore, our data suggest that the ICSI car be a useful tool to efficiently produce transgenic pig as well as other mammals.

• Plant Resources
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• v.6 no.2
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• pp.108-113
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• 2003

This study was carried out to obtain basic information for possibility of oral vaccine in carrot using Agrobacteruim -mediated transformation system. The epitope region of porcine epidemic diarrhea virus (PEDV) spike gene which is classified as a member of the Coronaviridae and causes an acute enteritis in pigs was successfully expressed in carrot (Daucus carota) using the Agrobacterium-mediated transformation system. Hypocotyl segments of in vitro germinated plantlets were infected with Agrobacteriun tumefaciens LBA 4404 harboring PEDV spike gene. Embryogenic callus (EC) was induced on MS selection medium with 1 mg/L 2,4-D, 50 mg/L kanamycin and 300 mg/L cefotaxime after 45 days of culture. Subcultured ECs on MS selection medium without 2,4-D were converted to somatic embryos (SE) of various stage; globular, heart and torpedo stage. Putative transgenic embryos were selected on MS medium with 50 mg/L kanamycin and 300 mg/L cefotaxime. Regenerated plantlets from transformed SE were induced on MS medium containing 50 mg/L kanamycin after 30 days of culture. Genomic PCR confirmed the integration of PEDV spike gene into nuclear genome of carrot and northern blot analysis demonstrated the expression of PEDV spike gene in transgenic carrot.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.148-156
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• 2019

The Transgenic livestock can be useful for the production of disease-resistant animals, pigs for xenotranplantation, animal bioreactor for therapeutic recombinant proteins and disease model animals. Previously, conventional methods without using artificial nuclease-dependent DNA cleavage system were used to produce such transgenic livestock, but their efficiency is known to be low. In the last decade, the development of artificial nucleases such as zinc-finger necleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regulatory interspaced short palindromic repeat (CRISPR)/Cas has led to more efficient production of knock-out and knock-in transgenic livestock. However, production of knock-in livestock is poor. In mouse, genetically modified mice are produced by coinjecting a pair of knock-in vector, which is a donor DNA, with a artificial nuclease in a pronuclear fertilized egg, but not in livestock. Gene targeting efficiency has been increased with the use of artificial nucleases, but the knock-in efficiency is still low in livestock. In many research now, somatic cell nuclear transfer (SCNT) methods used after selection of cell transfected with artificial nuclease for production of transgenic livestock. In particular, it is necessary to develop a system capable of producing transgenic livestock more efficiently by co-injection of artificial nuclease and knock-in vectors into fertilized eggs.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.239-245
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• 2011

The overexpression of Phosphoprotein Enriched in Astrocytes (PEA15) gene is commonly found in human diabetic patients. The overexpression of this gene in skeletal muscle and fat tissues have been reported to cause insulin resistance, thereby impairing insulin stimulated glucose uptake. We introduced a gene of mouse PEA15 (mPEA15) and enhanced green fluorescent protein (EGFP) into fertilized one cell pig zygotes using microinjection, and produced a piglet that showed overexpression of mPEA15 in the muscle tissues and expression of EGFP in the ear tissues and hooves. RT-PCR RFLP, southern blot and FISH analysis showed that the tissues carried the transgene. Real-time RT-PCR and western blots demonstrated that PEA15 gene was overexpressed in the various tissues and muscle tissues, respectively. These fads suggest that expression vector system is normally expressed in the transgenic (TG) pigs. To use as animal diseases model for type 2 diabetes, further study is necessary to confirm whether diabetes occur in these TG pigs, especially insulin resistance.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.133-137
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• 2009

Pluripotent embryonic stem (ES) cells isolated from inner cell mass (ICM) of blastocyst-stage embryos are capable of differentiating into various cell lineages and demonstrate germ-line transmission in experimentally produced chimeras. These cells have a great potential as tools for transgenic animal production, screening of newly-developed drugs, and cell therapy. Miniature pigs, selectively bred pigs for small size, offer several advantages over large breed pigs in biomedical research including human disease model and xenotransplantation. In the present study, factors affecting primary culture of somatic cell nuclear transfer blastocysts from miniature pigs for isolation of ES cells were investigated. Formation of primary colonies occurred only on STO cells in human ES medium. In contrast, no ICM outgrowth was observed on mouse embryonic fibroblasts (MEF) in porcine ES medium. Plating intact blastocysts and isolated ICM resulted in comparable attachment on feeder layer and primary colony formation. After subculture of ES-like colonies, two putative ES cell lines were isolated. Colonies of putative ES cells morphologically resembled murine ES cells. These cells were maintained in culture up to three passages, but lost by spontaneous differentiation. The present study demonstrates factors involved in the early stage of nuclear transfer ES cell isolation in miniature pigs. However, long-term maintenance and characterization of nuclear transfer ES cells in miniature pigs are remained to be done in further studies.