• Food Science of Animal Resources
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• v.32 no.4
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• pp.389-395
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• 2012

Cloned animals are a result of asexual reproduction of animals using somatic cell nuclear transfer. Ever since the first report of a cloned sheep 'Dolly' produced by SCNT, increasing numbers of livestock, such as bovine and swine clones, have been generated worldwide. Foods derived from cloned animals have not been produced yet. However, the food safety of cloned animals has provoked controversy. The EU Food Safety Authority and U.S. Food and Drug Administration announced that milk and meat from cloned and non-cloned animals have no difference regarding food safety. However, food derived from cloned animals is considered unsuitable for eating vaguely. Moreover, there were scant information about cloned animals in Korea. Therefore, we surveyed the number of cloned animals worldwide including Korea and summarized the reports for cloned animals and discussed predictable problems.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.177-182
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• 2009

This study was conducted to investigate the variation of growth characteristics and reproductive physiology in cloned Hanwoo male calves during growing stage. The hematological parameters, body weight, and plasma hormonal levels, birth to 12 months, were analyzed in the cloned calves (n=3). Differences among treatment means were determined by a student t-test. A probability of P<0.05 was considered statistically significant. The hematological parameters, such as white blood cell, red blood cell, and platelet, were not different in both normal and cloned calves. The difference of body weight, however, was significantly higher in the cloned calves, $5{\sim}6$ months (p<0.05) and $7{\sim}12$ months (p<0.01), than that of the comparators, respectively. The plasma IGF-1 level was statistically significant in the cloned calves, $5{\sim}10$ months, compared to that of the normal calves (p<0.05). However, the plasma testosterone level was not different in both normal and clone calves according to growing stage. Taken together, the cloned Hanwoo male calves are growing faster and maintaining a normal reproductive physiology.

• Reproductive and Developmental Biology
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• v.32 no.4
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• pp.249-253
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• 2008

Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.

• Reproductive and Developmental Biology
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• v.33 no.1
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• pp.19-24
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• 2009

This study was conducted to investigate the specific expression genes in the cloned bovine tissues. Donor cells, cloned tissues were analysed by RAPD-RFLP method. The results were detected three genes (CH-U7B, CH-U7M and CH-U7P) in the cloned fetus. It was found a single copy genes by southern hybridization. Sequence analysis of CH-U7M gene was shown 99% homology to a previously reported EST from a cloned bovine fetus. The putative ORF was encode a protein of hydrophobicity index 0.03. Semi-quantitative RT-PCR by using the CH-LS001 specific primer was remarkably detected in the lung tissue of cloned fetus. Further investigation of these genes may provide one of the key information to explain the early death, abnormal fetus, large off-spring and the low pregnancy rate in the production of cloned bovine.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.767-778
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• 2023

The aim of the research is to identify that porcine oocytes can function as recipients for interspecies cloning and have the ability to develop to blastocysts. Furthermore each mitochondrial DNA (mtDNA) in interspecises cloned embryos was analyzed. For the study, mouse-porcine and porcine-porcine cloned embryos were produced with mouse fetal fibroblasts (MFF) and porcine fetal fibroblasts (PFF), respectively, introduced as donor cells into enucleated porcine oocytes. The developmental rate and cell numbers of blastocysts between intraspecies porcine-porcine and interspecies mouse-porcine cloned embryos were compared and real-time polymerase chain reaction (PCR) was performed for the estimate of mouse and porcine mtDNA copy number in mouse-porcine cloned embryos at different stages.There was no significant difference in the developmental rate or total blastocyst number between mouse-porcine cloned embryos and porcine-porcine cloned embryos (11.1 ± 0.9%, 25 ± 3.5 vs. 10.1 ± 1.2%, 24 ± 6.3). In mouse-porcine reconstructed embryos, the copy numbers of mouse somatic cell-derived mtDNA decreased between the 1-cell and blastocyst stages, whereas the copy number of porcine oocyte-derived mtDNA significantly increased during this period, as assessed by real-time PCR analysis. In our real-time PCR analysis, we improved the standard curve construction-based method to analyze the level of mtDNA between mouse donor cells and porcine oocytes using the copy number of mouse beta-actin DNA as a standard. Our findings suggest that mouse-porcine cloned embryos have the ability to develop to blastocysts in vitro and exhibit mitochondrial heteroplasmy from the 1-cell to blastocyst stages and the mouse-derived mitochondria can be gradually replaced with those of the porcine oocyte in the early developmental stages of mouse-porcine cloned embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.477-481
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• 2007

Korean Ogol chicken has been registered as a natural monument in Korea and regarded as a valuable genetic resource for the world. As an initial step to investigate the genetic structures of this breed, phylogenetic analysis and calculation of genetic diversities have been performed using mitochondrial DNA (mtDNA) sequence variations. A total of 31 Korean Ogol chicken was grouped into four haplotypes and the large haplotype was represented in 12 individuals. The unrooted neighbor-joining tree indicates that the Korean Ogol chicken shared three (A to C) major chicken lineages representing the high genetic variability of this breed. These results can be used for making the breeding and conservation strategies for the Korean Ogol chicken.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.253-257
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• 2005

This study was carried out to evaluate the effects of washing medium, breed and washing temperature of fresh and frozen-thawed boar sperm on mitochondrial activity and membrane integrity by flow cytometry. More than $80\%$ of fresh sperm washed with mTLP-PVA medium at $20^{\circ}C$ exhibited an intact membrane and a functional mitochondrion. With frozen-thawed samples, a large number of sperm showed both damaged membrane $(36.4\~46.9\%)$ and nonfunctional mitochondrion $(55.1\~71.1\%)$ in the mTLP-PVA and BTS washing media at $20^{\circ}C$. There were no breed effects of fresh and frozen-thawed sperm on mitochondrial activity and membrane integrity. The percentages of damaged membrane of fresh and frozen sperm, respectively, were higher at $4^{\circ}C$ washing temperature than at $20^{\circ}C$ washing temperature in the mTLP-PVA medium. We found that washing medium and washing temperature of fresh and frozen-thawed boar sperm were important for the analyses of mitochondrial activity and membrane integrity by flow cytometry.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2006.11a
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• pp.77-79
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• 2006

한국재래오골계는 천연기념물로 등록이 되어 있어 세계의 중요한 유전자원 중 하나이다. 현재 한국에서 사육되어 있는 오골계의 유전적 특성을 규명하기 위하여 미토콘드리아 DNA의 변이를 이용하여 계통 분석을 실시하였다. 총 31 마리의 한국재래오골계가 이 분석에 이용되었으며 10개의 haplotypes이 관찰되었다. NJ 방법으로 만들어진 계통도 분석을 통하여 이미 닭에서 알려진 A부터 C의 lineage를 포함하는 것으로 보아 한국 재래오골계는 아직도 높은 유전적 다형성을 유지하고 있음을 알 수 있었다. 이 연구 결과는 한국 재래오골계의 육종 및 보존 계획을 세우는데 유용하게 이용될 수 있을 것으로 사료된다.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2008.05a
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• pp.91-91
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• 2008

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.711-717
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• 2007

In this study, two cell types from porcine females, namely fetal fibroblasts (pFFs) and adult ear fibroblasts (pAEFs) and two passages (3-4 and 7-8) were investigated by evaluating the development rate, blastocyst cell number and the incidence of apoptosis. No significant differences were observed in the cleavage rates of cloned and IVF embryos. The blastocyst rates between the embryos cloned with pFFs ($15.1{\pm}3.2$) and pAEFs ($10.4{\pm}2.6$) did not differ significantly but was significantly (p<0.05) lower in pAEFs than that in IVF ($22.5{\pm}4.5$) embryos. Total cell number in pFFs ($28.4{\pm}4.3$) and pAEFs cloned blastocysts ($24.2{\pm}5.1$) was significantly (p<0.05) lesser than IVF control ($35.4{\pm}3.2$). Apoptosis rates between cloned blastocysts differed significantly (p<0.05) and were significantly (p<0.05) higher than IVF embryos. The blastocyst rates between the cloned embryos cloned with different cell passages did not differ significantly but in embryos cloned with 7-8 cell passage was significantly (p<0.05) lower than the IVF control. Apoptosis signals were detected in IVF and cloned embryos as early as day 3 and the rates of apoptosis increased concurrently with the embryo development. In conclusion, high apoptosis during in vitro preimplantation development resulted in low development rate and total cell number of cloned embryos. Moreover, based on the apoptotic incidence in cloned blastocysts, fetal fibroblasts are more suitable for production of cloned embryos in porcine.