• The Science & Technology
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• v.33 no.7 s.374
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• pp.85-87
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• 2000

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.37-37
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• 2003

본 연구실에서는 체세포복제 수정란 이식우의 분만전후 태아와 모체 및 태반과의 내분비적인 관계를 검토하기 위해 복제수정란 이식우의 분만 전후에 있어서, 혈중progesterone 과 TGF-$\beta$$_1$ 수준을 분석한 결과 정상우의 분만직전과 달리 혈중progesterone 및 TGF-$\beta$$_1$ 농도는 감소되지 않고 높은 수준을 그대로 유지되어 복제수정란이식우의 경우 정상적인 분만 signal이 나타나지 않는 것으로 나타났다. 본 연구는 체세포 복제소 수정란 이식우에 있어서 태반조직의 특성을 정상우의 동일한 시기의 태반과 비교 검토하였으며 분만시기에 있어서 태반의 역할을 검토하였다. 태반은 복제란 이식우 및 정상우 임신우를 술을 실시하여 태반을 채취하여 실험에 공시하였다. 정상우의 임신기간중 혈중 progesterone 농도는 임신초기와 중기에 다소 증가되어 유지되다가 임신말기에는 급격한 progesterone의 감소현상과 더불어 분만이 유기되는 것으로 나타났으나 복제우의 경우 분만예정일 직전까지 progesterone의 급격한 감소는 일어나지 않고 높은 농도로 유지되는 현상을 보였다. 이때 제왕절제 수술중 제대근방에 있는 태반궁부를 적출하여 중량을 측정한 결과 정상우의 궁부에 비해 유의적으로 무거웠으며, 이것은 태아의 중량과 정의 상관관계가 있음이 확인되었으며 태아 및 궁부의 중량이 무거울수록 분만 전후의 태아사망율이 높은 것으로 나타났다 이때의 궁부를 조직학적으로 검토한 결과, 복제우의 태반궁부는 정상우의 궁부에 비해 cytotrophoblast 및 syncytiotrophoblast가 적었으며 치밀하지 못한 형태를 확인할 수 있었다. 이때의 태반조직를 이용하여 세포질을 추출하여 단백질양상을 검토한 결과, 정상태반에 비해 복제태반은분자량 90kd, 65kd 및 18kd의 특이단백질이 존재하고 있음을 확인할 수 있었으며 이들 단백질을 HPLC system에 의해 분리한 결과 fraction 2와 3에서 특이한 단백질을 분리하였다. 이와 같이, 복제우의 태반에는 정상적인 임신과 분만을 비롯하여 복제송아지의 생존에 중요한 인자가 관여하고 있을 확인할 수 있었다.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.19-19
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• 2003

소 난자 체외성숙에 있어 소 태아혈청 (fetal bovine serum: FBS)첨가시 높은 성숙율을 보이며 핵 이식 후 배 발달율에 있어서도 높다. 하지만 소 태아혈청은 hormone, growth factor, vitamine 그리고 다수의 어떤 잘 알려지지 않은 인자를 포함한 복잡한 배지로 알려져 있으며, 수정란 이식 후 태아의 발육중 및 태어난 직후에 발생되는 송아지에서 나타나는 몇몇 비정상적인 현상들의 원인인 것으로 보고되고 있다. 본 실험은 체외 배양시 소 태아혈청과 이의 대체물질로서 BSA 또는 PVA가 첨가된 배양조건에서의 복제 수정란의 배 발달율을 비교함과 동시에 배반포의 세포수 그리고 세포자연사 (Apoptosis)를 각각의 조건에서 비교함으로써 배발달에 미치는 효과를 알아보기 위하여 실시하였다. 핵이식은 소 체세포를 이용하였으며, 핵 이식 후 CR1aa 기본 배양액으로 FBS, BSA, 그리고 PVA를 첨가하여 5% $CO_2$, 5% $O_2$, 39$^{\circ}C$ 조건하에서 7~8일간 배양하였다.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.139-143
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• 2007

This study was performed to investigate the reproductive characteristics of the cloned Hanwoo bulls produced by SCNT. The semen ejaculated from the cloned bulls (C-38 and C-39) and normal Hanwoo bull was properly measured the volume, the number of sperm, and the viability of frozen-thawed sperm. The sperm activity was analyzed using computer assisted sperm analysis (CASA). To analyze fertilizing ability of the cloned bulls, in vitro fertilization and artificial insemination were performed using the frozen-thawed semen. There were no differences in semen volume, sperm concentration, and the viability of frozen-thawed sperm between cloned bulls and normal bull. The difference was statistically significant in total motility, curvilinear velocity (VCL), straight-line velocity (VSL), and average-path velocity (VAP) of both cloned bulls compared to those of normal Hanwoo bull, respectively (p<0.05). The cleavage and blastocyst development rate were not different between the groups. five cloned cows were artificially inseminated using the frozen-thawed semen of C-38, two of them became pregnant. Two second generation calves (one male and one female) were produced. Based on these results, the cloned Hanwoo bulls showed normal reproductive abilities of semen parameters and sperm activity to their comparators and produced cloned calves, although there are some individual differences on the parameters.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.639-645
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• 1997

The objectives of the present study were improvements in the efficiency of developmental rates to morula and blastocyst stages to produce a large number of genetically identical nuclear transplanted embryos. The oocytes collected from slaughterhouse ovaries were matured 24h in TCM199+10% FBS and exposed to $39^{\circ}C$ or room temperature to allow cytoplasmic maturation and gain activation competence. Donor embryos were treated for 12h with $10{\mu}g/ml$ nocodazole or $0.05{\mu}g/ml$ demicolcine to synchronize the cell cycle stage at 26h after the onset of culture. The blastomeres and recipient oocytes were fused by electrofusion. The cloned embryos were then cultured in various conditions to allow further development. In the treatment of oocyte activation and cell cycle regulation of donor nuclei, the room temperature exposure and nocodazole treatment group had significant effect on the developmental rates to morula/blastocyst(21.7% vs 12.1~16.7%), but had no significant effect on the fusion rates between donor blastomeres and recipient oocytes. The developmental rates of bovine nuclear transplanted embryos appeared to be higher significantly in mTALP medium under 5% $O_2$ condition and in TCM199 with bovine oviduct epithelial cell under 20% $O_2$ condition(22.2%) than other groups. In embryo transfer of nuclear transplanted embryos, there were no significant differences in calving rates between the use of excellent and good grade donor embryos.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.49-57
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• 2000

This study was conducted to investigate the developmental potential of cloned embryos derived from bovine fetal fibroblast cells, and the effect of quiescent treatment, passage number and origin of donor cells on in vitro development of cloned embryos. Fetal skin and liver-derived fibroblast cells were transferred to enucleated oocytes after serum starvation or nontreatment (cycling). After electrofusion. reconstituted embryos were activated with $Ca^{＋＋}$-ionophore and cycloheximide, and cocultured for 7~9 days with BRL cells. Some blastocysts were transferred to recipient cows 7~8 days post estrus. The development rate to the blastocyst stage of serum starved cell-derived embryos was higher (25.3%) than that of actively dividing cells-derived embryos (15.9%), The rates of blastocyst formation were 23.1~25.0% after transfer of cell passaged 4 to 6 times, and 23.8 and 25.2% after transfer of fetal skin and liver cells, respectively. After embryo transfer, 34.4% and 15.6% of recipient cows were pregnant on Day 60 and 120, respectively, and one male calf was produced from skin-derived vitrified blastocyst. The result of this study showed that the development of cloned embryos. was enhanced by quiescent treatment, but did not different among the cells passaged 4 to 6 times, and between skin and liver cells. This result also confirms that offspring can be obtained from the vitrified clone embryo derived from fetal skin cell.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.171-179
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• 1997

The objectives of the present study were improvements in the efficiency of developmental rates to morula and blastocyst stages to produce a large number of genetically identical nuclear transplant embryos. The oocytes collected from slaughterhouse ovaries were matured for 24 h and then enucleated and cultured to allow cytoplasmic maturation and gain activation competence. And then the donor embryos were treated for 12 h with 10 $\pi$g /ml nocodazole and 7.5 $\pi$g /ml cytochalasin B to synchronize the cell cycle stage at 26 h after the onset of culture. The blastomeres were transferred into the perivitelline space of the enucleated nocytes and blastomeres and oocytes were fused by electrofusion. The cloned embryos were then cultured in various conditions to allow further development. The age of the recipient(30 vs 40 h) had no significant effect on the fusion rates(82.4 vs 82.1%) and the developmental rates to morula /blastocyst(9.8 vs 11.0%). Effect of Nocodazole treatment on the donor cell cyle synchronization to improve the developmental rates of bovine nuclear transplant embryos was significantly higher than control group(21.4 vs 10.1%, p<0.05). Significant differences were in the percentage of fusion rates(72.9,77.1vs 61.9%) in three types of fusion medium(PBS(+), mannitol and sucrose, p<0.01). The developmental rates of bovine nuclear transplant embryos appeared to be highest in mSOF medium under 5% 0$_2$ condition, but no significant differences were found when compared with TCM199-BOEC and mSOF under two different oxygen ratio(5 and 20%).