• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2005년도 제5회 발생공학 국제심포지엄 및 학술대회
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• pp.122-123
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• 2005

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2004년도 제4회 발생공학 국제심포지움 및 학술대회
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• pp.115-115
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• 2004

• 한국동물위생학회지
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• 제33권3호
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• pp.223-231
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• 2010

A total of 191 samples collected from the commercial swine farms located in Chungnam province were investigated by PCR to estimate the prevalence of Lawsonia (L.) intracellularis infection. In the group of the pigs with proliferative enteritis, 14 (93.3%) of 15 intestinal samples and 12 (80.0%) of 15 feces were positive in PCR. In contrast, a relatively low positive rate (18.0%, 29 of 161 samples) was determined in the group of normal healthy pigs. The group of pigs over 120 days showed the highest positive rates (26.8%, 15 of 56 samples). In the comparison of the sequences of 210bp for species specific fragments and 301bp for outer membrane protein, the isolates (L1. L2) showed almost 100% identity with the reference L. intracellularis (L08049, USA). For the sequences of partial 16s rDNA, the homologies among the 5 isolates (L1-L5) were 97.4% to 99.3%, and those of 5 sequences (L1-L5) versus 5 overseas reference strains of L. intracellularis ranged from 98.6% to 99.8%. In the comparison of the nucleotide sequences among 5 isolates and other species in Desulfovibrionales showed 82.4 to 99.5% identities. The 5 isolates shared relatively low identities (76.9% to 84.4%) with the species of alpha-proteobacteria. In phylogenetic analysis based on the 16s rDNA sequences, all of the 5 isolates (L1-L5) were located in the same branch with the strains of L. intracellularis that were previously isolated from the pigs in USA and China. Seven strains of Desulfovibrio sp. were clustered in the neighboring branches, whereas alpha and gamma Proteobacteria showed distant relationship with L. intracellularis strains. The present findings suggest that L. intracellularis infection is endemic in the swine farms in the regions, and that the domestic isolates maintained very limited genetic variation.

• 대한수의학회지
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• 제44권4호
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• pp.551-559
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• 2004

Shiga toxin-producing Escherichia coli (STEC) causes various clinical signs in human and animals, and has been indicated as a global enteropathogen with zoonotic importance. In this study, the feces of healthy pigs were collected from the slaughtered pigs of Daejon abattoir during the period from December 2001 to October 2002. Of 326 specimens, 13 STEC were confirmed by culture, PCR and colony hybridization. The isolates were further studied for toxin types, pathogenic factors, plasmid profiles, and antimicrobial resistance to characterize the genetic and toxigenic properties. In PCR, all of 13 isolates were evident to have shiga toxin gene (stx). Of 13 isolates stx1 gene was detected in 4 and stx2 gene in 9. The genes of eaeA, hlyA and rfbE were not present in any isolates. In colony hybridization using shiga toxin common primer (STXc), 2 to 9 per 100 colonies subcultured from 13 isolates showed the positive reaction. In the examination for plasmid profiles of the isolates, one to eleven plasmids with varying sizes of 1.0 Kb to 100 Kb were detected, and the 13 STEC could be classified into four groups by the plasmid patterns. The antimicrobial resistance patterns of the isolates were comparably corresponded with the plasmid profile patterns.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.745-753
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• 2008

Gene-manipulated mice were discovered for the first time about a quarter century ago. Since then, numerous sophisticated technologies have been developed and applied to answer key questions about the fundamental roles of the genes of interest. Functional genomics can be characterized into gain-of-function and loss-of-function, which are called transgenic and knock-out studies, respectively. To make transgenic mice, the most widely used technique is the microinjection of transgene-containing vectors into the embryonic pronucleus. However, there are critical drawbacks: namely position effects, integration of unknown copies of a foreign gene, and instability of the foreign DNA within the host genome. To overcome these problems, the ROSA26 locus was used for the knock-in site of a transgene. Usage of this locus is discussed for the gain of function study as well as for several brilliant approaches such as conditional/inducible transgenic system, reproducible/inducible knockdown system, specific cell ablation by Cre-mediated expression of DTA, Cre-ERTM mice as a useful tool for temporal gene regulation, MORE mice as a germ line delete and site specific recombinase system. Techniques to make null mutant mice include complicated steps: vector design and construction, colony selection of embryonic stem (ES) cells, production of chimera mice, confirmation of germ line transmission, and so forth. It is tedious and labor intensive work and difficult to approach. Thus, it is not readily accessible by most researchers. In order to overcome such limitations, technical breakthroughs such as reporter knock-in and gene knock-out system, production of homozygous mutant ES cells from a single targeting vector, and production of mutant mice from tetraploid embryos are developed. With these upcoming progresses, it is important to consider how we could develop these systems further and expand to other animal models such as pigs and monkeys that have more physiological similarities to humans.

• 한국수정란이식학회지
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• 제32권2호
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• pp.53-58
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• 2017

It is very difficult to get the information about semen quality analysis in transgenic pigs because of limited numbers and research facilities. Therefore, in the present study, we analyzed the semen quality of transgenic boars generated for xenotransplantation research. Briefly, the semen samples were collected from 5 homozygous ${\alpha}1,3$-Galactosyltransferase knock-out ($GalT^{-/-}$) transgenic boars and immediately transported to the laboratory. These semen samples were decupled with DPBS and conducted to analyze semen parameters by a computer-assisted semen analysis (CASA) system. The boar semen were examined all 12 parameters such as total motility (TM), curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), and hyperactivated (HYP), etc. In results, among the 5 $GalT^{-/-}$ boars, three boars (#134, 144, and 170) showed normal range of semen parameters, but #199 and 171 boars showed abnormal ranges of semen parameters according to standard ranges of semen parameters. Unfortunately, #171 boar showed azoospermia symptom with rare sperm counts in the original semen. Conclusively, assessment of semen parameters by CASA system is useful to pre-screening of reproductively healthy boar prior to natural mating and artificial insemination for multiplication and breeding.

• Reproductive and Developmental Biology
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• 제31권1호
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• pp.15-20
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• 2007

가축의 번식과 수요를 조절할 수 있는 생물학적 자극 통제 수단으로 새로운 돼지 페르몬성 냄새 물질를 탐색하고자, 기질 분자로서 2-cyclohexyloxytetrahydrofurane (A), 2-phenoxytetrahydrofurane (B) 유도체들의 설명인자인 물리화학 파라미터와 돼지 페로몬의 수용체 (pOBP)에 대한 결합 친화력 상수($p[Od.]_{50}$) 간의 2D-QSAR 모델을 유도하고 검토하였다. 2D-QSAR 모델은 결합 친화력 상수를 약 96.4% 설명하는 매우 양호한 모델($r^{2}=0.964$)로서 분자내 치환기의 소수성 (SL) 상수에 관한 적정값이 $(SL)_{opt.}=1.418$일 때 가장 높은 결합 친화력을 나타냄을 알았다. 그러므로 분자내 치환기의 소수성 인자가 결합 친화력 상수에 가장 큰 영향을 미치는 중요한 요소이었다.

• Molecules and Cells
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• 제26권6호
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• pp.558-565
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• 2008

Although the fertilizing ability of spermatozoa is greatly reduced after freezing, complete understanding of alterations induced by cryopreservation has not been elucidated. The present study evaluates the effects of cryopreservation on the $Ca^{2+}$ handling of boar spermatozoa using several sperm activators. Intracellular $Ca^{2+}$ signals from single spermatozoa were measured using confocal $Ca^{2+}$ imaging of unfrozen samples and of other spermatozoa after having been frozen. Elevation of the external $K^{2+}$ concentration elicited a three times larger $Ca^{2+}$ increase in fresh spermatozoa than in cryopreserved spermatozoa. Caffeine elicited $Ca^{2+}$ transients with some oscillations in the fresh spermatozoa, but not in the thawed spermatozoa. Depletion of the $Ca^{2+}$ store with thapsigargin induced a rapid rise in $Ca^{2+}$ in the control but generated a smaller increase of $Ca^{2+}$ after thawing. Exposure to progesterone induced a biphasic rise of the $Ca^{2+}$ level in the fresh spermatozoa only. Sperm viability was reduced by cryopreservation. Resting $Ca^{2+}$ levels in fresh and cryopreserved spermatozoa were similar. Longer incubation (2.5 h) of thawed spermatozoa partly recovered the $Ca^{2+}$ response to the interventions. These results suggest that cryopreservation reduces the responsiveness of spermatozoa to depolarization, modulators of the internal $Ca^{2+}$ store and progesterone in terms of the $Ca^{2+}$ signal, thus providing a possible mechanism for reduced fertility observed in cryopreserved boar spermatozoa.

• 한국임상수의학회지
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• 제27권6호
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• pp.647-651
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• 2010

연속형 $CO_2$ 레이저와 펄스형 $CO_2$ 레이저를 이용한 돼지 피부절개 시 창상 치유에 미치는 영향을 평가하고자 본 실험을 실시하였다. 다섯 마리의 돼지(Landrace x Yorkshire) (45-51 kg, 4-6 개월령, 수컷 3마리, 암컷 2마리)를 이용 하였고, 각각의 돼지에서 우측 및 좌측의 등쪽 피부에 대칭적으로 연속형 $CO_2$ 레이저와 펄스형 $CO_2$ 레이저를 이용하여 절개($2{\times}2{\times}2cm^2$) 하였다. 양측 피부 절개는 Maxon 3-0 를 이용하여 봉합하였다. 수술 후 3, 7, 14, 21일에 병리조직학적 검사를 실시하였다. 창상 부위의 재상피화는 연속형 $CO_2$ 레이저 군에 비해 펄스형 $CO_2$ 레이저군에서 더 많이 이루어졌다. 육아조직 형성은 창상후 경과일 3일에 펄스 $CO_2$ 레이저군에서 유의적으로 높게 나타났다(P < 0.05). 섬유아세포는 창상후 경과일 7일에 펄스형 $CO_2$ 레이져군에서 유의적으로 많게 형성되었다(P < 0.05). 결론적으로 피부절개 시에 있어서 펄스형 $CO_2$ 레이저는 연속형 $CO_2$ 레이저에 비하여 재상피화, 육아조직형성 및 섬유아세포가 더 높게 나타났으며, 레이저 시술에 따른 조직손상을 적게 나타내었다. 따라서 피부절개 시에 있어서 펄스형$CO_2$ 레이저가 연속형 $CO_2$ 레이저 보다 더 적합할 것으로 판단된다.

• 한국동물위생학회지
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• 제43권4호
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• pp.227-236
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• 2020

In this study, we have developed 3D8 scFv transgenic pig (TG) by microinjection of fertilized one-cell pig zygotes (2.17%). The effect of 3D8 scFv TG on porcine reproductive and respiratory syndrome virus (PRRSV) resistance were evaluated through PRRSV VR2332 (1×103 TCID50/mL) challenge and transmission experiments. As a result, the average daily weight gain (ADWG) of TG increased compared to the wild type pigs (WT) in PRRSV challenge groups and the serum viremia levels of the TG was significantly lower than of WT on the 7 day and 21 day after infection, meaning that the viral shedding was suppressed by 3D8 scFv expression. These results suggest that the expression of 3D8 scFv in pig could suppress spreading of infected virus to pigs sharing a room.