• Korean Journal of Veterinary Service
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• v.39 no.4
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• pp.231-237
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• 2016

The present study was conducted to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. During March to December 2015, a total of 1,160 lung samples out of 58 herds were collected randomly from pigs slaughtered in Jeonbuk province. In addition, 290 hilar lymph nodes from pig with pneumonic lung lesion (5 samples per herd) were screened for selected viral and bacterial pathogens. Gross lesions of lungs such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis and liver white spots were examined. The overall prevalence of SEP was 64.3% (746/1,160). In the analysis of seasonal prevalence, there was an increase of occurrence during the spring months (287/400, 71.8%) and decrease during the fall months (93/200, 46.5%) among the whole herds. The mean number of SEP score per pig was $1.20{\pm}1.28$. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 25.5% (296/1,160), 44.1% (512/1,160), 3.8% (44/1,160) and 17.6% (204/1,160), respectively. The most frequent region with lung lesion was diaphragmatic lobes (left 17.1%, right 17.3%). In the detection of viral pathogens by PCR, porcine circovirus type2 (PCV2) was positive in 86.9% (252/290), while porcine reproductive and respiratory syndrome virus (PRRSV) was not detected, In the case of bacterial pathogens, 50 microorganisms were isolated by PCR and/or microbiological test. The most frequently isolated bacteria was Streptococcus suis (20, 34.4%), followed by Pasteurella multocida (17, 29.3%), Streptococcus spp. (11, 3.4%), Actinobacillus pleuropneumoniae (2, 8.9%).

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.856-860
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• 2000

Cloning technology continues to capture widespread attention by the international news media and biomedical and agricultural industries. The future uses of this technology could potentially contribute to major advances in biomedical and agricultural sciences. Cloned transgenic dairy cattle possessing milk promoters directing transgenes will produce pharmaceutical proteins in their milk faster, more efficiently and less expensively than transgenic cattle created using microinjection techniques. Additionally, cloned transgenic fetuses and animals may become a source of cells, tissue and organs for xenotransplantation. Lastly, but maybe most importantly, enhanced production traits and disease resistance may be realized in animal agriculture by utilizing these new technologies. The recent advances in the cattle cloning technology are important but there are still major obstacles preventing widespread commercial use of this technology. The type of donor nucleus, recipient cytoplasm, and cloning procedures used will impact the potential number of clones produced and the uses of the technology. In addition, the new advances in cloning methodology have not improved the relatively low pregnancy rates or reduced the incidence of health problems observed in cloned offspring. These problems may require novel techniques to decipher their cause and new methods of preventing and/or diagnosing them in the preimplantation embryo. The commercial potential is enormous for cloning technology; however, little has been done to improve the efficiencies of the procedure. Improving procedural efficiencies is a critical developmental milestone especially for potential uses of cloning technology in animal agriculture.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.3
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• pp.289-300
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• 1997

Newborn dog chymosin was extracted from the stomachs of dogs of 2 weeks of age, and was purified by ion exchange chromatography. Half of the sequence was determined by amino acid sequencing and the complete sequence was deduced from a cloned chymosin cDNA Results showed that the zymogen showed 79% sequence identity with calf prochymosin and 54% identity with porcine pepsinogen A The size of the propart and location of the residue which becomes the amino-terminus in the active enzyme was the same in the prochymosins. The maximum general proteolytic activity at pH 3.2 of newborn dog chymosin was 3-4% of that of porcine pepsin A at pH 2, whereas the milk clotting activity relative to the general proteolytic activity of newborn dog chymosin was much higher than that of calf chymosin. Agar gel electrophoresis at pH 5.2 of stomach extracts of individual dogs showed the existence of two predominant genetic variants of zymogen and enzyme. The two variants could not be distinguished by amino acid composition or amino-terminal sequencing, and no differences in the enzymatic properties of the genetic variants were observed. It was concluded that of the residues that participate in the substrate binding, calf and newborn dog chymosin differ in the following positions (porcine pepsin numbering, subsites in parentheses) : Ser 12 Thr(S$_4$), Leu 30 Val(S$_1$/S$_3$), His 74 Gln(S'$_2$), Val 111 Ile(S$_1$/S$_3$), Lys 220 Met(S$_4$). With regard to the low general proteolytic activity of newborn dog chymosin, the substitution Asp303 Val relative to calf chymosin may contribute to an explanation of this.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.153-158
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• 2008

Tissue-specific and temporal regulation of milk protein gene expression is advantageous when creating transgenic animal that produces foreign protein into milk. Gene expression, i.e. protein production, is regulated not only by promoter strength but also mRNA stability. Especially, poly A tail length by polyadenylation affects in vivo and in vitro mRNA stability and translation efficiency of the target gene. In the present study, nucleotide sequence of 3'-UTR was analyzed to evaluate the effects of mRNA stability on the target gene expression. Based on the poly A signal of 3' -untranslated region (UTR), nucleotide sequences of putative cytoplasmic polyadenylation elements (CPEs) and downstream elements (DSEs: U-rich, G-rich, GU-rich) were analyzed and used to construct 15 luciferase reporter vectors. Each vector was transfected to HC11 and porcine mammary gland cell (PMGC) and measured for dual luciferase expression levels after 48 hours of incubation. Luciferase expression was significantly higher in construct #6 (with CPE 2, 3 and DSE 1 of exon 9) and #11 (with CPE 2, 3 and DSE 1, 2 and 3 of exon 9) than construct #1 in the PMGC. These results suggest that expression of target genes in PMGC may be effectively expressed by using the construct #6 and #11 on production of transgenic pig.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.89-94
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• 2015

Respiratory disease in pigs is common in modern pork production worldwide and is often referred to as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. The control of swine respiratory disease requires an understanding of the interactions between the organisms that can cause this illness, the pig and management of the environment. This study was carried out to investigate the lesion of red internal organs in slaughtered pigs and provided assistant data for pig farms. A total of 900 lung samples, 45 farms were collected randomly from slaughtered pigs in Jeonbuk province from April to December in 2014. Gross lesions such as swine enzootic pneumonia (SEP), pleuritis, pleuropneumonia, pericarditis, liver white spots were examined for the pigs. Overall prevalence of SEP was 70.8%. According to season, the incidence occurred higher in summer than winter, fall and spring. The mean SEP score was 1.4, the highest incidence occurred in fall. The prevalence of pleuropneumonia, pleuritis, pericarditis, and milk spot was 26.1%, 71.4%, 2.8%, 21.6%, respectively. In the detection of pathogens, PRRS was not detected, PCV2 was positive in 87.6%.

• Korean Journal of Animal Reproduction
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• v.27 no.4
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• pp.317-324
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• 2003

The present study were performed to analysis the hematocrit and the red blood cells content into the blood plasma of the transgenic pigs harboring recombinent human erythropoietin gene (rhEPO). Mouse whey acidic protein (mWAP) linked to rhEPO gene was microinjected into pronuclei of porcine one-cell zygotes. After delivered of offspring, PCR analyses identified one mWAP-rhEPO transgenic founder offspring(F$_{0}$). The first generation of transgenic pig (F$_{0}$) harboring mWAP-hEPO appeared to be a male, and the second generation (F$_1$) pigs were made by natural mating of F$_{0}$ with domestic swine, and male and female transgenic pigs (F$_1$) were identified by PCR. The blood samples from transgenic and normal pigs were collected for 50 days during lactation and were counted the red blood cell (RBC) numbers and Hematocrit (HCT) content into the blood. The transgenic pigs expressing rhEPO in their blood gave rise to higher RBC numbers and HCT contents than control animals. rhEPO was secreted both in the blood and milk of genetically engineered pigs harboring rhEPO gene. Therefore, this study provides a model regarding the production of transgenic pig carrying hEPO transgene for biomedical research.earch.

• Journal of Life Science
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• v.26 no.3
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• pp.275-281
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• 2016

Glycan modification is important in pharmaceutical industry. Especially, sialic acid affects the bioactivity and stability of medicine. Milk of pig has been used as bioreactor to produce various pharmaceutical proteins. Therefore, it is necessary to modify the glycan chain in pig mammary grand. β-1,4-N-Acetylglucosaminyltransferase A (pMGAT4A) is one of the essential enzymes for increase of sialic acid content, but pig MGAT4A is unclear. In this study, the pMGAT4A was identified and characterized. The pMGAT4A has 1638 nucleotides encoding 535 amino acids and type II membrane topology, which is one of the common features in many glycosyltransferases. The gene was strongly expressed in liver and mammary gland, whereas was weakly expressed in small intestine, stomach and bladder. For functional test, HA-tagged MGAT4A was over-expressed in porcine kidney (PK-15) cell line. Forced expression of pMGAT4A gene was identified by qPCR, and we identified that pMGAT4A is located in Golgi complex by co- staining with HA antibody and BODIPY TR ceramide. In addition, we identified the increase of mannose-β-1,4-N-acetylglucosamine structure by ELISA and immunofluorescence using Datura stramonium agglutinin (DSA), which recognizes mannose-β-1,4-Nacetylglucosamine. Through the specific activity analysis, we showed that pMGAT4A modified bi-antennary to tri-antennary. This event affects sialic acid content. Therefore, we thought that over-expression of pMGAT4A will be necessary in pig mammary grand for improved medicine.

• Journal of Life Science
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• v.28 no.4
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• pp.389-397
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• 2018

The structure of glycan residues attached to glycoproteins can influence the biological activity, stability, and safety of pharmaceutical proteins delivered from transgenic pig milk. The production of therapeutic glycoprotein in transgenic livestock animals is limited, as the glycosylation of mammary gland cells and the production of glycoproteins with the desired homogeneous glycoform remain a challenge. The ${\beta}$-1,3-N-acetylglucosaminylatransferase1 (B3GNT1) gene is an important enzyme that attaches N-acetylglucosamine (GlcNAc) to galactose (Gal) residues for protein glycosylation; however, there is limited information about pig glycosyltransferases. Therefore, we cloned the pig B3GNT1 (pB3GNT1) and investigated its functional properties that could attach N-acetylglucosamine to galactose residue. Using several different primers, a partial pB3GNT1 mRNA sequence containing the full open reading frame (ORF) was isolated from liver tissue. The ORF of pB3GNT1 contained 1,248 nucleotides and encoded 415 amino acid residues. Organ-dependent expression of the pB3GNT1 gene was confirmed in various organs from adult and juvenile pigs. The pB3GNT1 mRNA expression level was high in the muscles of the heart and small intestine but was lower in the lungs. For functional characterization of pB3GNT1, we established a stable expression of the pB3GNT1 gene in the porcine kidney cell line (PK-15). As a result, it was suggested that the glycosylation pattern of pB3GNT1 expression in PK-15 cells did not affect the total sialic acid level but increased the poly N-acetyllactosamine level. The results of this study can be used to produce glycoproteins with improved properties and therapeutic potential for the generation of desired glycosylation using transgenic pigs as bioreactors.