• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.64-64
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• 2001

To facilitate the widespread application of somatic cell cloning, improvements in blastocyst production efficiency and subsequent fetal viability are required. Area where technical improvements are needed include donor cell treatments, starvation and passage numbers. This study was carried out to investigate the effect of serum-starvation and passage on the development of ear skin fibroblast cells cloned embryos. A skin biopsy was obtained from the ear of a 2-year-old Korean Hanwoo female. The cells were cultured in 10% FBS＋DMEM up to 2-3 months(up to 10 passages) and then used. In Experiment 1, the Korean bovine Ear Skin Fibroblast cells (KbESF) were either serum starved (culture in 0.05% FBS＋DMEM) or serum fed (10% FBS＋DMEM) for 4-7 days Prior to NT In Experiment 2, the KbESF cells used for nuclear transfer in these experiments were from passages 2 to 10. The development of 208 nuclear transfer (NT) embryos reconstructed from either serum starved or serum fed ear skin fibroblast was assessed. NT embryos reconstructed from serum starved and serum fed cells showed the same developmental rate (cleavage 80.16 vs. 85.37%; blastocyst 20.63 vs. 19,51%). The development of 590 nuclear transfer (NT) embryos reconstructed from passage 2 to 10 was assessed. We observed the same developmental rates for embryos derived from later Passages as compared with those embryos from early passages(blastocyst from 16.69 to 27.91%, average 20.17%). There was no significant difference between serum-fed and serum-starved donor cells. We observed no difference in developmental rates for embryos derived from 2 to 10 passages. These data show that prolonged culture and serum starvation does not affects the cloning competence of adult somatic cells.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.66-66
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• 2002

The efficiency of animal production using cloning technology is relatively low. It is considered that the nuclear transferred (NT) embryos proceed inappropriate reconstruction with donor-recipient cell, which lead to a abnormal embryo development, and differential expression of mRNA transcript. Especially, the expression of mRNA on peri-implantation stage embryos is very important factor to decide success of implantation and ongoing pregnancy. (omitted)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.68-68
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• 2002

Positional cloning of hereditary deafness genes is a direct approach to identify molecules and mechanisms underlying auditory function. Nowadays many deafness genes are newly identified by finding the locus for the causative genes. Mutations at many different loci in humans and mice are known to cause hearing impairment. Mouse mutants exhibiting deafness may be useful in identifying some of genes involved. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.6
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• pp.892-897
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• 2005

Macrophage colony-stimulating factor (M-CSF) is a growth factor required for growth and differentiation of mononuclear phagocyte lineage. Total and 16 poly (A) mRNA of bovine M-CSF were isolated from healthy bovine peripheral mononuclear cells stimulated by phobol 12-myristste 13-acetate (TPA). The more compatible cultured mononuclear cells were 5${\times}$10/ml for RNA isolation. TPA-activated mononuclear cells increased the level of M-CSF-mRNA more than concanavalin A (Con A) and lipopolysaccharide (LPS). The optimal analysis of reverse transcriptase-polymerase chain reaction (RT-PCR) for14 Macrophage colonystimulating factor (M-CSF) as a growth factor required for bovine M-CSF was denaturation at 94$^{\circ}C$ for 1 minute, annealing at 57$^{\circ}C$ for 1 minute, extension at 72$^{\circ}C$ for 1 minute for 30 cycles. The size of cDNA of bovine M-CSF by RT-PCR was 774 base pairs. A 774 base pairs cDNA encoding bovine M-CSF was synthesized by reverse transcriptase polymerase chain reaction (RT-PCR). Ligated cDNA was transformed to competent cells and then plasmid isolation and digestion was performed. Molecular cloning and sequencing were performed for cDNA of bovine M-CSF. The size of cloned cDNA of bovine M-CSF was 774base pairs. The homology of base sequence and amino acid sequence was 88% and 86% compared with known human M-CSF, respectively. From a high degree of sequence similarity, the obtained cDNA of bovine M-CSF is thought be a specific gene of bovine M-CSF.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.453-460
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• 2007

An overview of developments important in the future of animal breeding is discussed. Examples from the application of quantitative genetic principles to selection in chickens and mice are given. Lessons to be learned from these species are that selection for production traits in livestock must also consider selection for reproduction and other fitness-related traits and inbreeding should be minimized. Short-term selection benefits of best linear unbiased predictor methodology must be weighed against long-term risks of increased rate of inbreeding. Different options have been developed to minimize inbreeding rates while maximizing selection response. Development of molecular genetic methods to search for quantitative trait loci provides the opportunity for incorporating marker-assisted selection and introgression as new tools for increasing efficiency of genetic improvement. Theoretical and computer simulation studies indicate that these methods hold great promise once genotyping costs are reduced to make the technology economically feasible. Cloning and transgenesis are not likely to contribute significantly to genetic improvement of livestock production in the near future.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.208-209
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• 2005

• Proceedings of the Korean Society of Grassland Science Conference
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• 2005.06a
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• pp.172-173
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• 2005

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2001.10a
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• pp.43-43
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• 2001

no Abstract, See Full Text

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.419-424
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• 1998

The present study was carried out to examine the efficiency of cloning of transgenic embryos by nuclear transfer(NT) using gene-injected rabbit embryos. The rabbit embryos at pronuclear stage were microinjected with methallothionein-human growth hormone(MT-hGH) gene and cultured to 8- and 16-cell in TCM-199 containing 10% FCS with a monolayer of rabbit oviductal epithelial cells in a 5% $CO_2$incubator. The recipient oocytes were collected from the oviducts 14~16 h after hCG injection. The oocytes were enucleated and activated with 5$\mu$M ionomycin and 2mM 6-dimethylaminopurine. Blastomeres form gene-injected embryos were transferred into the enucleated oocytes by micromanipulation. The nuclear transplant oocytes were electrofused and co-cultured with rabbit oviductal cells. Following 120 h of culture, blastocysts were prepared for gene analysis by polymerase chain reaction(PCR). In previous experiment, the rate of gene-positive embryos detected by the nested PCR analysis was significantly decreased while developing to blastocyst(25%)(Kang et al., 1998). The fusion rate of gene-injected blastomeres was significantly(P＜0.05) lower than non-injected blastomeres(66% vs 80%). However, the NT embryos that were derived from gene-injected donor embryos did not differ from control embryos in development to the blastocyst stage(39% vs 31%). Of the 43 NT blastocysts developed from the gene-injected donor embryos, twelve(28%) were positive for the injected DNA. The results indicate that NT with gene-injected embryos can be successfully used for cloning and multiplication of transgenic embryos, furthermore applicable to improvement of transgenic animal production.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.487-495
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• 2007

The objectives of the present study were to initiate cloning of Korean native goat by somatic cell nuclear transfer (NT) and to examine whether unovulated (follicular) oocytes can support the same developmental ability of NT embryos as ovulated (oviductal) oocytes after hCG injection in stimulated cycles of the goat. The in vivo-matured and immature oocytes were collected from the oviducts and follicles of superovulated does, respectively, and the immature oocytes were maturated in vitro. Ear skin fibroblasts derived from a 3-yr-old female Korean native goat were used as the donors of nuclei or karyoplasts. Following fusion, activation and in vitro culture to a 2- to 4-cell stage, 49 in vitro-derived and 105 in vivo-derived embryos were transferred to 6 and 17 recipient does, respectively. One doe and three does of the respective groups were identified as pregnant by ultrasonography on day 30 after embryo transfer. However, only one doe, which had received in vivo-derived embryos, delivered a normal female kid of 1.9 kg on d 149. The cloned kid gained more weight than her age-matched females as much as 87% during the first 4 mo after birth (17.7 vs. $9.4{\pm}0.8$ kg) and reached puberty at 6-mo age a few months earlier than normal female does. The telomere length of the kid, which was similar to that of the donor fibroblast at 2-mo age, decreased 8% between 2- and 7-mo ages. Moreover, at 7-mo age, she had 21% shorter telomere than her age-matched goats. To our knowledge, this is the first case in which a cloned animal born with a normal weight exhibited accelerated growth and development. The unusually rapid growth and development of the cloned goat may have resulted from SCNT-associated epigenetic reprogramming involving telomere shortening.