• 한국수정란이식학회지
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• 제8권2호
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• pp.151-157
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• 1993

The present study was undertaken to determine the optimal condition for parthenogenetic activation of rabbit oocytes by electric stimulation in vitro in an attempt to develop nuclear transplantation techniques for cloning mammalian embryos and animals. Freshly ovulated oocytes were collected from superovulated rabbits from 13 to 26 hrs. after hCG injection. The cumulus-free oocytes were activated parthenogetically by repeated stimuli of square direct electric pulses in O.3M mannitol solution. After applying electric stimulations of different voltages, pulse durations and pulse times, all of the oocytes were cultured in TCM-199 with 10% FCS for 96 hours in a 5% $CO_2$ incubator, and their developmental potential in vitro was examined. The higher activation rate (68.9%) was achieved at the voltage of 2.0kv/cm, the pulse duration of 60 $\mu$sec and three pulse times and the activation rate of 100% was achieved at the pulse duration of 100 and 200 $\mu$sec, the voltage of 1.5kv/cm and three pulse times. Although the higher rates of activation of oocytes were achieved at 100 and 200 $\mu$sec, none of them developed to blastocyst in vitro. The oocytes collected 18~20 hours post hCG injection showed the highest rate of activation and development to blastocyst in vitro than the oocytes collected 13~15 or 25~26 hours post hCG injection. Therefore, it can be suggested that the application of electric stimulation of 2.0kv/cm, 60 $\mu$sec and three pulse times to the oocytes collected at 18~20 hours post hCG injection would be more beneficial for the parthenogenetic activation of oocytes in rabbits.

• 한국수정란이식학회지
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• 제17권3호
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• pp.203-209
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• 2002

본 실험은 원시난포의 체외배양 체계를 확립할 수 있는 가능성을 검토하기 위해 10일과 20일령 마우스의 난소에서 분리한 난포를 체외배양하여 난포의 형태변화, 난자의 성장를 및 난자의 핵성숙단계를 조사하여 비교하였다. 그 결과를 요약하면 다음과 같다. 1. 10일령과 20일령의 마우스에서 분리한 난포는 배양 6일째부터 난포강이 형성되었다. 2. 10일령과 20일령 마우스의 난소에서 분리한 난포의 수는 평균 21.5와 33.3개였고, 배양하기 전에 투명대를 제외한 난자의 직경은 51.85 $mu extrm{m}$와 57.50 $\mu\textrm{m}$였으나, 10 일간 배양한 후 측정한 난자의 직경은 55.95 $\mu\textrm{m}$와 63.11 $\mu\textrm{m}$로 증가하였다. 3. 10일령과 20일령에서 M II까지 핵이 성숙된 난자는 각각 4.3%와 22.1%였고. GVBD기 이상은 각각 14.5%와 61.1%였다.

• 한국수정란이식학회지
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• 제17권3호
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• pp.195-201
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• 2002

본 실험은 원시난포의 체외배양 체계를 확립할 수 있는 가능성을 검토하기 위해 0, 5, 10, 15 및 20일령 마우스에서 분리한 난소를 20, 15, 10, 5 및 0일동안 organ culture 하여 난소의 성장률, 난자의 회수율과 성장률 및 난자의 핵성숙 단계를 조사하여, 비교 ·검토하였다. 그 결과를 요약하면 다음과 같다. 1. Organ culture 전과 후의 각 일령에 따른 난소의 면적 차이는 0일령 35.9%, 5일령 8.7%, 10 일령 1.2% 및 15일령 14.4%로 15일령을 제외 하고는 배양일령이 증가할수록 면적 차이는 감소하였다. 2. Organ culture 후 난자의 회수율과 난자의 직경은 배양일령이 증가할수록 증대되었다. 3. GV기 이상의 핵성숙은 organ culture 후 배양 일령이 증가할수록 진행되는 단계에 있는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.495-499
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• 2006

In our previous studies, we demonstrated that Vascular Endothelial Growth Factor (VEGF) enhances bovine oocyte maturation and early embryonic development in serum supplemented media. In this experiment, to determine the synergistic effect of VEGF with serum components on early embryonic development in vitro in cattle, 1 mg/ml polyvinyl-alcohol (PVA) was replaced with foetal bovine serum (FBS) in maturation and culture media. Bovine oocytes were matured in Synthetic Oviduct Fluid (SOF) supplemented with PVA, PVA+5 ng/ml of VEGF, FBS, or FBS+VEGF. Fertilized oocytes were cultured in the same conditions for 8 days. The development of embryos was examined at 48 h post- insemination and on days 6, 7 and 8. The results were analyzed using repeated measures two- factor ANOVA, in which the effects of VEGF and serum were assigned as two factors. The development rate to 4- to 8-cell embryos at 48 h was significantly higher in the PVA+VEGF group than in the PVA group (44.7% and 31.5%, respectively). However, the highest development rate to 4- to 8-cell embryos was obtained from the FBS+VEGF group (58.8%). On day 8, the blastocyst rates were higher in the PVA+VEGF (22.8%), FBS (32.1%, p<0.05) and FBS+VEGF (42.1%, p<0.05) groups than in the PVA group (17.1%). Two- factor ANOVA of the development rates indicates that VEGF had a significant effect, but had no synergistic effect with serum components on early embryonic development. The results of the present study demonstrate that VEGF improves the in vitro developmental competence of bovine oocytes and/or embryos independent of the effect of serum components.

• Asian-Australasian Journal of Animal Sciences
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• 제14권6호
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• pp.759-764
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• 2001

This study was carried out to investigate the effect of activation timing, cell cycle and passage on the development of embryos produced by cumulus cell nuclear transfer in Hanwoo (Korean cattle). Nuclear donor cumulus cells were cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $38.5^{\circ}C$ in a humidified atmosphere of 5% $CO_2$ in air. The 1~6 passages of serum deprived or actively dividing cumulus cells were isolated and used as donor cells. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. One pulse of 180 volts for $15{\mu}s$ was applied to induce the fusion between karyoplast and cytoplast. The activation was done before or after the fusion. To activate, oocytes were treated with $10{\mu}M$ calcium ionophore for 5 min immediately followed by 2 mM 6-dimethylaminopurine for 3 h. The nuclear transfer embryos were cultured in $500{\mu}l$ of modified CRlaa supplemented with 3 mg/ml BSA in four well dish covered with mineral oil. After 3 days culture, culture medium was changed into modified CRlaa medium containing 1.5 mg/ml BSA and 5% FBS for 4 days. The incubation environment was 5% $CO_2$, 5% $O_2$, 90% $N_2$ at $38.5^{\circ}C$. There was no blastocyst formation when the nuclear transfer embryos were activated before the fusion, whereas, 29.9% of blastocyst formation was shown when the nuclear transfer embryos were activated after the fusion. When serum deprived and actively dividing cumulus cells were used as nuclear donor cells, the developmental rates to blastocyst were 38.5% and 40.6%, respectively. There was no significant difference between serum deprived and actively dividing cells in the developmental rates. The developmental rates to blastocyst according to 1~6 passages were 37.5~44.4%. However, there were no significant differences among passages. These results indicate that 1~6 passage cumulus cell irrespective of cell cycle could support development of nuclear transfer embryos activated after the fusion.

• Reproductive and Developmental Biology
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• 제31권2호
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• pp.127-131
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• 2007

Embryonic germ (EG) cells are undifferentiated stern cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

• 대한수의학회지
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• 제63권4호
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• pp.40.1-40.7
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• 2023

To optimize the most efficient method for porcine in vitro maturation (IVM), we compared the effects of supplementing extracellular vesicles (EVs) derived from porcine follicular fluid (pFF). The cumulus oocyte complexes were grouped into 4 groups with different supplementations as following: pFF (G1), pFF-depleted EVs (G2), EVs (G3) and control (G4) groups. After IVM with different supplementations, maturation rates and the developmental competences of porcine oocytes and blastocyst development were investigated. Additionally, glutathione (GSH) and reactive oxygen species (ROS) levels were measured in mature oocytes. The EVs were isolated and characterized with cryo-TEM and nanoparticle tracking analysis. The pFF significantly affected the maturation rate, whereas the presence of EVs did not show notable difference in the maturation rates. Although there were numerical increases in the measured parameters in EV and pFF-depleted EVs groups, no significant differences were observed between them. The EV group showed similar oocyte maturation rate for both positive and negative control groups. The GSH was not different among the groups, but ROS levels were significantly lower in pFF-supplemented group when compared with other groups with the highest level in the control group. G2 group wasn't significantly different G1 and G3 group. G3 group wasn't significantly different from G2 and G4 group. This suggests that EVs in IVM medium which probably effected partially to protect against oxidative stress and potentially enhance the quality of oocytes. This study indicates that the EVs in pFF play a significant role in improving the efficiency of oocyte maturation in porcine.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.229-229
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• 2004

The identification of embryo-specific genes would provide insights into early embryonic development. However, the current methods employed to identify the genes that are expressed at a specific developmental stage are labor intensive and suffer from high rates of false positives. Here we employed a new and accurate reverse transcription-polymerase chain reaction (RT-PCR) technology that involves annealing control primers (ACPs) to identify the genes that are specifically or prominently expressed in bovine early blastocysts and hatched blastocysts produced in vitro. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.739-747
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• 2000

This experiment was conducted to evaluate the influence of dimethyl-sulfoxise (DMSO, 0, 5, 50, 100 and $500{\mu}M$) on the motility and acrosome reaction of the frozen-thawed spermatozoa from 3 different bulls (Bull A, Band C). Also we evaluated the developmental capacity of bovine embryos fertilized in a medium containing DMSO at various concentrations. DMSO had negligible effects on the sperm motility and acrosome reaction in all three bulls. However, the development rates from 2 to 16 cells stage on the 3rd day after insemination with 50, 100 and $500{\mu}M$ DMSO in Bull-B, and up to the blastocyst stage fertilized with 5, 50, 100 and $500{\mu}M$ in Bull-A were significantly higher (p<0.05) than those of control ($0{\mu}M$ DMSO) group from each bull. Furthermore, the rates of blastocysts per cleaved embryos of 5 to $500{\mu}M$ DMSO group in Bull-A and of 5 to $100{\mu}M$ DMSO in Bull-C were also significantly higher (p<0.05) than those for their $0{\mu}M$ groups, respectively. These results indicate that DMSO at micromol level used for in vitro fertilization might stimulate the development of embryos for some bulls.

• Reproductive and Developmental Biology
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• 제30권1호
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• pp.21-26
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• 2006

본 연구는 체외성숙 배지에 첨가하는 PVP의 농도, EGF, cysteine 및 PVP의 단독 또는 혼합첨가가 한우 체외수정란의 체외발생에 미치는 영향을 검토하였다. 체외성숙 배지에 PVP의 첨가농도$(0.1{\sim}3.0%)$에 따른 분할율은 차이가 없었으나, 배반포 발달율은 0.5% PVP 첨가군이 가장 높았다(P<0.05). PVP, EGF 및 cysteine의 단독 및 혼합 첨가에 따른 분할율은 cysteine 단독첨가군이 높았으나(P<0.05), 배반포 발달율은 차이가 없었다. Inner cell mass 수는 대조군과 cysteine 첨가군이 PVP 첨가군에 비하여 유의하게 높았고(P<0.05), 총 세포수도 cysteine 첨가군에서 가장 높았다. 수정란이식 결과는 대조군, EGF, cysteine 및 EGF+cysteine 군의 임신율은 $46.1{\sim}63.6%$로서 비슷하였으나, PVP 첨가군은 10%로서 다른 군에 비하여 유의하게 낮았다(P<0.05). 본 연구 결과는 체외성숙 배지에 PVP의 첨가로 배 발생은 가능하지만, 세포의 품질에는 악영향을 미치는 것을 보여준다.