• 한국수정란이식학회지
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• 제9권2호
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• pp.153-160
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• 1994

This study evaluated the influence of cell stage of donor nucleus on nuclear injection, electrofusion and in vitro development in the rabbit to improve the efficiency of nuclear transplantation in the rabbit. The embryos of 8-, 16- and 32-cell stage were collected from the mated does by flushing viducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FGS) at 44, 54 and 60 hours after hCG injection. The blastorneres separated from these embryos were used as donor nucleus. The ovulated oocytes collected at 14 hours after hCG injection were used as recipient cytoplasm following removing the nucleus and the first polar body. The separated blastomeres were injected into the enucleated oocytes by micromanipulation and were electrofused in 0.28 M mannitol solution at 1.5 kV /cm, 60 $\mu$sec for three times. The fused oocytes were cocultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FGS for 72~120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. The cultured nuclear transplant embryos were stained with Hoechst 33342 solution and the number of cells were counted by fluorescence microscopy. The successful injection rate of 8-, 16- and 32-cell-stageblastomeres into enucleated oocytes was 86.7, 91.0 and 93.9%, respectively. The electrofusion rate of 8-, 16- and 32-cell-stage blastomeres with enucleated oocytes was 93.3,89.3 and 79.0%, respectively. Development of blastomeres to blastocyst was similar with 8-,16- and 32-cell-stage donor nuclei(26.2, 25.8 and 26.6%, respectively, P<0.05). The mean number of cell cycle per day during in vitro culture in nuclear transplant embryos which received 8-, 16- and 32-cell- stage nuclei was 1.87, 1.81 and 1.43, respectively.

• 한국발생생물학회지:발생과생식
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• 제3권1호
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• pp.59-67
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• 1999

초기배아의 발생과정동안 배아와 모체에서 발현되는 여러 cytokine은 착상을 위한 신호물질로 중요한 역할을 한다. 그 중 interleukin-1$\beta$ (IL-1$\beta$)는 배아와 모체간의 상호 신호전달체로서 성공적인 착상을 위한 필수적인 요소로 작용한다고 알려져 있다. 따라서 본 연구에서는 초기배아의 발생과정에 있어서 IL-1$\beta$ 유전자의 역할을 규명하기 위해 생쥐 초기배아에서의 IL-l$\beta$ 유전자의 발현양상을 역전사중합효소연쇄반응을 통해 조사하였고, IL-l$\beta$ 유전자의 발현에 미치는 수란관과 자궁내막세포의 영향을 밝혀보기 위해 공배양방법을 이용하였다. 그 결과 IL-l$\beta$ in vivo 에서는 4-세포기부터 포배기까지, in vitro에서는 상실배부터 부화중 포배기까지 발현하는 양상을 보였다. 또한 수란관과 자궁내막세포와의 공배양시 대조군과 비교하였을 때 실험군에서 IL-l$\beta$ 유전자의 발현이 촉진되었다. 이러한 결과는 IL-l$\beta$ 의 존재가 착상전 초기배아의 발생에 중요한 역할을 한다는 것을 의미한다. 또한 수란관과 자궁내막세포와의 공배양을 통해 IL-1$\beta$ 유전자의 발현이 수란관과 자궁요소에 의해 조절됨을 확인하였다.

• 한국임상수의학회지
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• 제12권1호
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• pp.877-886
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• 1995

The recycling nuclear transplantation(NT) technique has the powerful potential of producing a large number of genetically identical embryos and offsprings from one embryo. Multiple generational cloning by this technique utilizes the NT embryo itself as the donor for the next generation of cloning. In this experiment, we have produced the third generational cloned embryos by recycling NT. Further we examined comparatively the electrofusion rate and in vitro developmental potential in the cloned embryos of the first second and third generations. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulberco's phosphate buffered saline containing 10 % fetal calf serum(FCS) at 47 hours after hCG injection. In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gl/S transition of 32-cell stage. The first and second generation NT embryos developed to 16-cell were used as donor nuclei for second and third generation. The recipient cytoplasms were utilized the oocytes collected at 14 hours after hCG injection, following revoming the nucleus and the first polar body by micromanipulation. The separated blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were fused by electrical stimulation. The electrofusion rate was seen to be 78.0, 88.0 and 90.3 % in the first second and third generation NT rabbit embryos, respectively. The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10 % FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. The in vitro developmental potential to blastocyst stage was significantly(P<0.05) decreased in the third(7.2 %) generation NT embryos compared to the first(53.1 %) and second(16.1 %) generation NT embryos. Following in vitro development to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The mean blastomere numbers and cell cycle numbers of NT embryos during the culture period were significantly(p<0.05) decreased in the second(93.9 cells and 6.55 cylces) and third(81.5 cells and 1.35 cylces) generation, compared to the first(189.9 cells and 7.55 cylces) generation.

• 한국수정란이식학회지
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• 제10권1호
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• pp.73-82
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• 1995

large scale production of cloned embryos requires the technology of multiple generation nuclear transplantation(NT) using NT embryos as the subsequent donor nuclei. The purposes of this study were producing the second generation cloned rabbit embryos, and also to determine the electrofusion rate and in vitro developmental potential comparatively in the cloned embryos of the first and second NT generation. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FCS) at 47 hours after hCG injection In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gi /S transition of 32-cell stage. The first generation NT embryos which were developed to 8-cell were synchronized in Gi /S transition phase of the following 16-cell stage and used as donor nuclei for second generation Synchronization of the cell cycle of blastomeres was induced, first, using an inhibitor of microtuble polymerization, colcemid for 10 hours to arrest blastomeres in M phase, and secondly, using a DNA synthesis inhibitor, aphidicolin for 1.5 to 2 hours to arrest them in Gi /S transition boundary. The recipient cytoplasms were obtained by removing the nucleus and the first polar body from the oocytes collected at 14 hours after hCG injection. The separated donor blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 $\mu$sec at 1.25 kV /cm in 0.28 M rnannitol solution The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. Following in vitro culture of the first and second generation cloned embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The results obtained were summarized as follows: 1. The electrofusion rate was found to be similar as 79.4 and 91.5% in the first and second generation NT rabbit embryos, respectively. 2. The in vitro developmental potential to blastocyst stage of the second generation NT embryos (23.3%) was found significantly(p<0.05) lower, compared with that of the first generation NT embryos (56.8%). 3. The mean blastomeres counts of embryos developed to blastosyst stage following in vitro culture for 120 hours and also their daily cell cycles during the culture period were decreased significantly (p<0.05) to 104.3 cells and 1.33 cylces in the second NT generation, compoared with 210.4 cells and 1.54 cycles in the first NT generation, respectively.

• 한국수정란이식학회지
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• 제11권3호
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• pp.249-258
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• 1996

To improve the efficiency of in vitro production of embryos with follicular oocytes in Korean Native cows, the recovery rates, in vitro maturation, fertilization and development, and the time required for collecting and processing oocytes by aspiration with or without slicing were evaluated comparatively. The ovaries were obtained from a local abattoir and placed in physiological saline at 25~28$^{\circ}C$ and brought to the laboratory within 3 hrs. The oocytes were collected by aspiration of follicles(2~6mm) with or without slicing ovaries after aspiration, and classified into Grade I, Grade II, Denuded, Expanded oocytes by the morphology of cumulus cells attached and the homogeneity of cytoplasmic granules. Also the time required for each step of collecting and processing oocytes were measured. The cumulus cells were removed in some Grade I oocytes to measure their size and nuclear configuration before and after in vitro maturation. The Grade I oocytes were matured in vitro(IVM) for 24 hrs. in TGM-199 supplemented with 35$\mu$g /ml FSH, 10$\mu$g /ml LH, 1 $\mu$g /ml at 39$^{\circ}C$ under 5% C02 in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24hrs. and then the zygotes were cocultured in vitro (IVC) with bovine oviductal epithelial cells for 10 days. The results obtained were as follows: The number of oocytes recovered per ovary was averaged 6.6 by aspiration and 11.2 by slicing post aspiration, which summed to 17.8. The number of Grade I oocytes recovered per ovary was averaged 3.1 by aspiration and 3.6 by slicing, which summed to 6.7. The percentage of Grade I to total oocytes recovered was significantly(P<0.05) higher as 48.0 % in aspiration than 31.6% in slicing post aspiration. The time requlred for recovering a Grade I oocyte by aspiration and slicing was 1.1 and 2.5 min, respectively. The mean diameter of Grade I oocytes by aspiration and slicing was similar as 148.7 and 151.5$\mu$m, respectively. The percentage of Metaphase II stage oocytes after IVM for 24 hours was significantly (P

• 한국수정란이식학회지
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• 제33권4호
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• pp.221-228
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• 2018

The osmolarity of a medium that is commonly used for in vitro culture (IVC) of oocytes and embryos is lower than that of oviductal fluid in pigs. In vivo oocytes and embryos can resist high osmolarities to some extent due to the presence of organic osmolytes such as glycine and alanine. These amino acids act as a protective shield to maintain the shape and viability in high osmotic environments. The aim of this study was to determine the effects of glycine or/and alanine in medium with two different osmolarities (280 and 320 mOsm) during IVC on embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. To this end, IVC was divided into two stages; the 0-2 and 3-7 days of IVC. In each stage, embryos were cultured in medium with 280, 320, or 360 mOsm and their combinations with or without glycine or/and alanine according to the experimental design. Treatment groups were termed as, for example, "T(osmolarity of a medium used in 0-2 days of IVC)-(osmolarity of a medium used in 3-7 days of IVC)" T280-280 was served as control. When PA embryos were cultured in medium with various osmolarities, T320-280 showed a significantly higher blastocyst formation (29.0%) than control (22.2%) and T360-360 groups (6.9%). Glycine treatment in T320-280 significantly increased blastocyst formation (50.4%) compared to T320-280 only (36.5%) while no synergistic was observed after treatment with glycine and alanine together in T320-280 (45.7%). In contrast to PA embryonic development, the stimulating effect by the culture in T320-280 was not observed in SCNT blastocyst development (27.6% and 23.7% in T280-280 and T320-280, respectively) whereas the number of inner cell mass cells was significantly increased in T320-280 (6.1 cells vs. 9.6 cells). Glycine treatment significantly improved blastocyst formation of SCNT embryos in both T280-280 (27.6% vs. 38.0%) and T320-280 (23.7% vs. 35.3%). Our results demonstrate that IVC in T320-280 and treatment with glycine improves blastocyst formation of PA and SCNT embryos in pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제11권4호
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• pp.398-403
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• 1998

The objective of the present study was to examine the developmental rates, and the stage of development in relation to time since fertilization, of in vitro produced buffalo embryos. Buffalo cumulus-oocyte complexes obtained from slaughterhouse ovaries were matured and fertilized in vitro. The fertilized oocytes (n = 248) were then co-cultured with buffalo oviductal epithelial cells and evaluated for the developmental stages on Days 2, 4, 6, 7, 8, 9 and 10 post-insemination. The peak of 4-cell stage embryos was observed on Day 2 (63.7 %), whereas Day 4 was marked by peaks of 6-8-cell stage embryos (20.9%) and 16-cell stage embryos to early morulae (50%). On Days 6, 7, 8, 9, and 10 post-insemination, 49.5, 48.3, 38.3, 33.8 and 33.4% embryos were found to be at morula/compact morula stages, 8.8, 12.5, 25.4, 6.0 and 1.2% at early blastocyst/blastocyst stages, 0, 6.8, 7.2, 15.3 and 2.0% at expanded blastocyst stage and 0, 1.6, 4.8, 19.3 and 38.5% hatching/hatched blastocyst stages, respectively. The peaks of early blastocyst/blastocyst, expanded blastocyst and hatching/hatched blastocyst stages were observed on Days 8, 9 and 10, respectively. The percentages of oocytes which initially became arrested and subsequently degenerated were 3.6, 4.8, 10.4, 14.5, 21.3 and 24.5% on Days 4, 6, 7, 8, 9 and 10 post-insemination, respectively.

• 한국가축번식학회지
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• 제20권4호
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• pp.413-421
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• 1997

체외에서 포유동물의 난자와 정자의 배양에 관한 연구는 난자의 성숙과정과 수정현상에 대한 많은 새로운 정보를 제공하였다. 동시에 체외수정의 연구로부터 얻은 결과는 또다른 의문을 제기하였다. 특히 동결융해정액을 이용한 돼지체외수정의 경우 낮은 정자의 침입율과 전핵형성율 및 높은 다정자침입(polyspermy)율은 아직도 해결해야할 문제점으로 남아있다. 돼지난자의 성숙에 관한 연구의 성과는 수정후 낮은 전핵형성율을 개선시켰으나 타동물종에 비하면 아직도 매우 낮게 나타나고 있다. 한편 동결정액의 처리를 위하여 caffeine이나 Ca2+와 같은 물질을 수정용 배지내에 첨가하는 등 수정능력획득의 유기를 위하여 여러 가지 방법이 연구되고 있지만 정자의 침입율은 아직도 낮고, polyspermy의 발생율은 높게 나타내고 있다. 따라서 정자의 침입율을 향상시키고 polyspermy를 억제하기 위하여 난관세포와의 공동배양, 난포액을 첨가한 배양액 내에서 정자의 전배양 및 정자농도의 조절은 매우 효과적인 방법으로 이용되어왔다. 그러나 수정란의 체외생산성 향상과 이와 관련된 연구를 보다 효과적으로 수행하기 위해서는 위에서 지적한 문제에 영향을 미치는 요인에 대한 보다 근본적인 이해가 요구된다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.7-12
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• 2001

Factors Affecting the Survival of Frozen Thawed Bovine In Vitro Produced Blastocysts. The effect of some factors on the post-thaw survival of a total of 240 in vitro produced bovine blastocysts was investigated using logistic regression analysis. The explanatory variables tested were: type of culture medium before freezing (TCM 199 supplemented with BSA, BSAITS (BSA+insulin+transferrin+selenium), ECS (estrous cow serum) with or without BOEC (bovine oviductal epithelial cells), age of the blastocyst (Day 7, Day 8+9), morphological appearance before freezing (distinct=Q1 or indistinct=Q2 inner cell mass) and type of cryoprotectant (glycerol, 1.0 M or ethylene glycol, 1.6 M). The survival after thawing based on the post-thaw quality and the development after co-culture with BOEC for 24 and 48 hours. Day 7 blastocysts had an almost three times better chance of survival than Day 8+9 blastocysts. Q1, Day 8+9 blastocysts had higher odds to survive after 48 hours in culture than Q2 blastocysts (p<0.05). Blastocysts produced in BSAITS medium had the best chances of survival; however, the odds were not always significant. Blastocysts frozen in glycerol had a better post-thaw quality rating than those frozen in ethylene glycol; however, the difference in post-thaw development at culture was not significant. The relationship between post-thaw quality and post-thaw development at culture was significant (p<0.05). The developmental stage and/or age of the embryo and culture medium where development up to blastocyst takes place affect the post-thaw survival of the bovine embryos.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.842-849
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• 2007

The purpose of the present study was to produce live offspring from in vitro fertilized goat embryos. Oocytes were collected from abattoir ovaries and kept in oocyte collection medium. Oocytes were washed 4-5 times with maturation medium containing medium-199 with 5 ${\mu}g/ml$ FSH, 100 ${\mu}g/ml$ LH, 1 ${\mu}g/ml$ estradiol-$17{\beta}$ 50 ${\mu}g/ml$ gentamycin, 10% inactivated estrus goat serum, and 3% BSA (fatty acid free). Oocytes were placed in 100 ${\mu}l$ drops of maturation medium containing granulosa cell monolayer and incubated in a 5% $CO_2$ incubator at $38.5^{\circ}C$ for 27 h. For capacitation of spermatozoa fresh semen was processed and mixed in 3 ml fertilization TALP medium containing 50 ${\mu}g/ml$ heparin and kept in the above incubator for 2 h. The capacitated spermatozoa were coincubated with matured oocytes for fertilization. Cleaved embryos were separated and cultured in embryo development medium with oviductal cells and 494 embryos were produced. Recipient goats were synchronized with two injections of 15 mg $PGF_{{2}{\alpha}}$/goat 10 days apart. Eighty early stage embryos were transferred into the uterotubal junction of 14 surrogate mothers using laparoscopy techniques. One recipient delivered twin kids, whereas another two recipients each.delivered a single kid The parentage of these kids was evaluated using highly polymorphic co-dominant microsatellites markers. From the present study, it was concluded that live goat kids can be produced from in vitro matured and fertilized goat embryos, to the best of our knowledge for the first time in India.