• 한국수정란이식학회지
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• 제12권3호
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• pp.307-313
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• 1997

Experiments were conducted to assess the effect of quality and viability of bovine blastocysts derived from in-vitro culture(IVC) of in vitro matured and fertilized(IVM-IVF) oocytes during their transport 2 hours. Follicular oocytes were collected form ovaries obtained at a slaughterhouse and were cultured for 24 hours in TCM-199. The IVM oocytes were fertilized in vitro with caudal epididymis spermatozoa. Fertilized oocytes were cultured for 7 to 9 days, and embryos that developed to the blastocyst stage were used for the experiment. The blastocysts, packed in straws with storage medium that consisted TCM-199 with HEPES equilibratd in air and supplemented with 10% FCS were transported at 39~(2.0 h). The quality of blastocysts was assessed and ranked as A(excel-lent), B(Good), fair or poor after transportation. The percentages of A and B grade blastocysts after transport duration for < 1 hours(97.7%) were similar to the result from transport duration for 1~2 hours (92.9%) and 2~3 hours(89.6%), but significantly(P<0.05) higher than transpot duration for 3~4 hours(76.3%). The percentages of A and B grade blastocysts after transport duration for two hours from developed blastocyst at 7day(100%) and 8day(85.0%) were higher 9day(96.6%) and >9day (40.0%). And early to expanded blastocyst produced in vitro were transferred to recipient cow by additional embryos at 7 and 8th day after AI. Three of them were pregnant to term and produced four twin calves, and two calves was premature birth. The gestation lengths of male to female and female to female twin were 282 and 281 days, respectively. And birth weight of twin calves were male to female(22.Skg) and female to female twin(20.3Okg), respectively.

• 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.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2004년도 제4회 발생공학 국제심포지움 및 학술대회
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• pp.15-17
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• 2004

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.650-654
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• 2003

The accuracy of Polymerase chain reaction (PCR) assay in sexing of sheep embryos was assessed in this study. A total of 174 ovine embryos produced in vitro at different stages of development (2, 4-8 cell stages, morula and blastocyst) were sexed. The universal primers (P1-5EZ and P2-3EZ) used in this assay amplified ZFY/ZFX-specific sequences and yielded a 445 bp fragment in both sexes. Restriction enzyme analysis of ZFY/ZFX-amplified fragments with Sac I exhibited polymorphism between sexes, three and two fragments in males and in females, respectively. For verification of accuracy, blood samples of known sex were utilized as positive controls in each test. The mean percentages of sex identification by this method at 2 cell, 4-8 cell, morula and blastocyst were $73.00{\pm}5.72$, $89.77{\pm}3.79$, $3.33{\pm}8.08$ and $79.6{\pm}9.09$, espectively with the over all male to female ratio of 1:0.87. It is concluded that the ZFY/ZFX based method is highly reliable for the sexing of sheep embryos.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.966-975
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• 1999

Technologies on preimplantation porcine embryos have been developed quickly and significantly. Successful development of systems for culture of porcine zygotes to the blastocyst stage has made it possible to utilize follicular oocytes for in vitro production of embryos and thus stimulated research on various embryo technologies. Recent technological development of embryo cryopreservation, separation of X- and Y-bearing spermatozoa and non-surgical embryo transfer has also made it easy to utilize in vivo- and in vitro-produced embryos for artificial manipulation to produce clones and transgenic pigs. Further progress in overcoming various problems associated with each embryo technology will result in acceptable efficiency to utilize porcine embryos with a high or increased quality. Combining these technologies will accelerate further expansion of the swine industry not only for meat production but also for the production of therapeutic recombinant proteins and xonografts.

• 한국수정란이식학회지
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• 제11권2호
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• pp.125-135
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• 1996

The present study was carried out to investigate the effects of cryoprotectants, equilibration step, freezing rate, culture condition following in vitro fertilization, and age and development stage of embryo by freezing with conventional slow freezing and vitrification on survival of frozen-thawed Korean native cattle(KNC) blastocysts produced in vitro. The KNC blastocysts produced in vitro were equilibrated in 1.8M ethylene glycol or 1.4M glycerol and cooled from -6$^{\circ}C$ to -35$^{\circ}C$ at -0.3$^{\circ}C$ or -O.6$^{\circ}C$ /minute. When equilibrated in 1.8M ethylene glycol, survival rate of fiozen4hawed blastocysts was sarne in both -0. 3$^{\circ}C$ /min and -0.6$^{\circ}C$ /min cooling rate(71.4%). With the equilibration in 1.4M glycerol, survival rate was higher in -0.3$^{\circ}C$ /min(63.6%) than in -0.6$^{\circ}C$ /min cooling rate(53.8%). For vitrification of the KNC blastocysts produced in vitro, they were equilibrated in 2-step or 3-step exposure to vitrification solution(25% ethylene glycol + 25% glycerol). Survival rate was sirilar in both 2-step(45.0%) and 3-step exposure(47.4%). According to culture condition following in vitro fertilization, higher survival rate was obtained for blastocysts co-cultured with bovine oviductal epithelial cell(BOEC, 77.3%) than for those cultured with epidermal growth factor(EGF, 65.7%) or for those co-cultured with BOEG + EGF (54.8%). According to embryo age and development stage, higher survival rate was obtained for 7-day ernbryos(70.0%) than 8-day(56.8%) or 9-day(20.0%) for blastocyst stage and obtained for 8-day embryos(74.3%) than 7-day(62.5%) or 9-day(42.9%) for exponded blastocyst. In surnmary, higher survival rate of frozen4hawed KNC blastocysts produced in vitro were obtained by using ethylene glycol for cryoprotectant and -0.3$^{\circ}C$ /min for cooling rate. And higher survival rate were obtained with co-culture with BOEC for culture condition following in vitro fertilization and with 7-day blastocyst or 8-day expanded blasto cyst for embryo age and development stage.

• 한국수정란이식학회지
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• 제8권2호
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• pp.143-149
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• 1993

The objective of this study was to produce calves derived from in vitro fertilization of in vitro matured follicular oocytes. Oocytes aspirated from small antral folicles of ovaries obtained at a local slaughter house were matured and fertilized in vitro. At l8hrs after insemination with Korean native cattle semen, oocytes were co-cultured for 6~7 days by utilizing co-culture system with bovine oviduct epithelial cell. After co-culture, good or excellent quality late morulae or early blastocysts were selected by morphological criteria under stereo microscope. Selected embryos were transferred to recipients on day 6 or 7 (estrus = day 0). Recipients were monitored by observation for estrus and rectal palpation after 60 days from embryo transfer. One of them went to term with the birth of a calf. This case is the first production of calf derived from in vitro fertilization in Korea.

• 한국가축번식학회지
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• 제19권3호
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• pp.161-169
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• 1995

To investigate the metabolism of various substrates in preimplantation bovine embryos, uptake of glucose and pyruvate, and lactate production were measured in single IVF-derived bovine embryos by a non-invasive method. When the embryos were incubated for 5 h in culture medium supplemented with 1 mM glucose and 0.4mM pyruvate as substrates at each developmental stage, glucose uptake was increased with more advanced developmental stages while pyruvate uptake was decreased. Total lactate producton of 2-cell embryos was significantly higher than that of blastocysts (p<0.05). Both of glucose uptake and lactate production in normal morulae produced in vitro was significantly high compared to the degenerated embryos(p<0.05). The results obtained in the study suggest that pyruvate as an exogenous substrate may be support in bovine embryos until 8-cell stage, whereas glucose may be effective as an energy source after morula stage. In addition, it was proven thatlactate was not effective as an energy source in preimplantation development of IVF-derived bovine embryos.

• 한국임상수의학회지
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• 제13권2호
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• pp.149-152
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• 1996

This study was carried out to evaluate the efficiency of production of cloned embryos by nuclear translatation (NT) when using 4-cell to compact morula stage embryos as nuclear donor. In micromanitulation and electrofusion of blastomeres from 4-cell to morula stage embryos, the successful injection rate was higher with late stage blastomeres, on the contrary the fusion rate was lower. The in vitro developmental rate of NT embryos was not significantly different between cell-stages of donor blastomeres. Although the overall rate of production of cloned embryos with 4-cell. 8-cell, early and late morula stage embryos was 14.0, 18.0, 15.3 and 14.1%, respectively, the mean number of blastocysts produced with a donor embryo was the most (4.51) with the compact morulae. Therefore, it can be suggested that the embryos at thelate stage is more beneficial for the mulciple production of cloned embryos, If the late stage blastomeres have maintained their totipotency to produce intact offspring.

• 대한수의학회지
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• 제30권2호
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• pp.231-241
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• 1990

The present study was carried out to investigate the viability of frozen-thawed aggregated mouse embryos and to produce the chimeras. Different phenotypic embryos were obtained by mating ICR female mice with ICR or CBA male mice. The aggregated morulae were produced following aggregation of embryos at 4-, 8- and 12- to 16-cell stage. The desirable stage for the aggregation of the mouse embryos was 8- to 16-cell stage. The post-thawed in vitro survival rates of aggregated embryos in glycerol, DMSO and ethylene glycerol were 51.5, 78.6 and 69.4%, respectively. Although the higher survival was obtained in DMSO, there were no significant differences in the survival rates among the three cryoprotectants. A total of 155 frozen-thawed aggregated embryos were transferred to 11 recipient mice, 3 out of 7 offsprings were born to overt chimera. These experiments have proven that mouse chimeras can be obtained from frozen-thawed aggregated embryos.