• Journal of Embryo Transfer
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• v.12 no.3
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• pp.335-341
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• 1997

The aims of this study are to establish a stable isolation method of blastomeres from bovine early embryos and examine their developmental potential in vitro Early embryos were produced by maturation and fertilizaion in vitro of bovine follicular oocytes. Blastomeres were isolated from 2~8-cell embryos in $Ca^2$+-, $Mg^2$+-free PBS+EDTA after removing the zonae pellucidae Isolated blastomeres were cultured in CZB containing BOEC for upto 240 hpi. Cleavage rates of them were 18.5%(10 /54) in 1 /2 blastomeres, 33.3%(16/48) in 1/4 blastomeres and 34.2%(14 /41) in 1/8 blastomeres, respectively. The rates of blastocystic vesicle formed were 8.7%(4 /46) in 1/2 blastomeres, 26.6% (17/64) in 1/4 blastomeres and 10.3%(8 /78) in 1/8 blastomeres, respectively. Blastomeres developed into various types of blastocystic vesicles and trophoblastic vesicles as evidenced by the Hoechst 33258 staining and morphology. This results suggest that the isolation method used and subsequent culture of isolated blastomeres from bovine early embryos should be useful to obtain extra embryonic cells for various analyses such as PCR and putative ES cell culture.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.247-251
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• 1997

This research was conducted to observe developmental capacity of the early embryos aggrigated to phytohemagglutinin-M(PHA-M) in the culture of mouse embryos in vitro. The results showed that the development of blastocyst increased to 2-celT >< 2-cell : 68. 9%, 4-cell $\times$4-cell : 92.5% and 8-cell $\times$8-cell : 97.3% in the aggrigated embryos of ICR mouse, and 2-cell $\times$ 2-cell : 90.0%, 4-cell $\times$4-cell : 93.9% and 8-cell $\times$ 8-cell : 100% in the aggrigated embryos of two different strains (ICR $\times$ CBA/J mouse). (Key words : aggrigated embryos, in vitro 2-cell block, phytohemagglutinin-M, blastocyst)

• Journal of Embryo Transfer
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• v.11 no.2
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• pp.137-144
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• 1996

The present study was carried out to obtain the pregnancy and delivery rate following transfer of fresh and frozen-thawed Korean native cattle(KNC) blastocysts(1~4 em-bryos / head) produced in vitro to Holstein recipients. The pregnancy rate of fresh and frozen-thawed KNC blastocysts produced in vitro was 50%(7 /14 heads) and 38.5%(5 /13 heads), respectively. The pregnancy rate of frozen-thawed KNC blastocysts produced in vitro frozen using 1.5M ethylene glycol and 1.4M glycerol for cryoprotectant was 33.3%(2 /6 heads) and 42.9 %(3 /7 heads), respectively. Seven calves including 2 sets of twin were born fiom 5 pregnant recipients receiving eleven fresh blastocysts. Three pregnant recipients were aborted among four pregnant recipients receiving twelve frozen-thawed blastocysts and one calf was born from the rest of one pregnant recipient.

• Journal of Embryo Transfer
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• v.17 no.3
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• pp.195-201
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• 2002

This study was to assess the developmental capacity of oocytes matured in vitro after 20, 15, 10, 5 and 0 days of organ culture when ovaries were isolated from juvenile mice at 0-, 5-, 10-,15- and 20-day old, respectively, and to develop in vitro culture system that observed a view to morphology of ovaries and nucleus maturation of oocytes. The size of ovaries decreased 35.9%, 8.7%, 1.2% and 14.4% after 20, 15, 10, 5 days of organ culture when the ovaries were isolated from 0-, 5-, 10 and 15-day old mice, respectively. After organ culture, the recovery rates, diameters of oocytes and the number of oocytes progressed from GV to MII were increased as increasing age of mice.

• Korean Journal of Animal Reproduction
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• v.7 no.2
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• pp.41-52
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• 1983

Animal in dustry in Korea urgently needs the domestic introduction and the industrial a, pp.ication of embryo transfer technique. Namely, this technique can be utilized effectively, as means of the improvement of livestocks, as means of the increase of meat production, as means of substitute for the livestock import, and dissemination of new breed. However, as this technique avaliable in our country is remaining initial stage, we can not make use of the technique industrially unless we make much improvement as follows; induction of superovulation, non-surgical recovery of embryos, synchronization between the estrus such cycles of donor and recipient, non-surgical transfer of embryos, etc. Simultaneously, the basic studies such as harvesting oocytes from ovary, in vitro culture of oocytes, in vitro capacitation of spermatozoa, cloning by culture of blastomeres and transfer of nuclei, sexing embryo, etc. should not be neglected in order to make the technique of embryo transfer more simple and convenient. For the success of these studies, universities, national and public institutes, large scale cattle farms, and small scale cattle farms should cooperate each other. For instance, universities undertake basic researches, and the national and public institutes a, pp.y the results of the researches to animal industry along with cooperation by large scale cattle farms. By the help of the cooperative organizations, the technique relevant to our environment and farm condition may be able to be finalized, and to be a, pp.ied to samll scale cattle farm. Consequently, being served to stimulate animal productivity, this technique can be contributed to the development of livestock industry in Korea.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.189-193
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• 2010

We investigated the cleavage rate and blastocyst yield for each culture condition to enhance tolerance of cryo-preservation of bovine IVF embryo with relatively lower cryo-tolerance compared to in vivo embryo. The cleavage rate and blastocysts yield for CR1aa, IVMD, IVD, CR1aa+10% FBS were 73.2, 69.3, 72.8, 68.5% and 44.1, 30.8, 33.3, 48.0%, respectively. The values did not differ among each treatments without serum. For embryo vitrification, In vivo and In vitro blastocysts were exposed to VS1(10% glycerin, 0.1 M glucose, 0.1 M sucrose, PEG 1%) for 5 min, and VS2 (10% glycerin, 10% EG, 0.2 M glucose, 0.2 M sucrose, PEG 2%) for 5 min and then VS3 (10% glycerin, 30% EG, 0.3 M glucose, 0.3 M sucrose, PEG 3%) for 1 min. The exposed embryos were then loaded into the 0.25 ml plastic straws and then plunged into liquid nitrogen. The straws were held for period of 1 to 2 weeks before thawing. In embryo viability, no differences in blastocyst re-expansion rates were found between in vivo and in vitro embryos. whereas expansion-BL rates was significantly higher for in vivo-derived embryos (72.7%) when compared to in vitro-derived embryos (51.4%), respectively (P<0.05). In conclusion, our results indicate that combined use of CRIaa culture medium with vitrification might enhance tolerance of cryopreservation for bovine IVF embryo production.

• Journal of Embryo Transfer
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• v.8 no.2
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• pp.91-95
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• 1993

The studies on the carried out to investigate the effects of co-culture with uterine fluids and uterine epithelial cells on the in-vitro fertilization and developmental rate of porcine follicular oocytes. The ovaries were obtained from slaughtered swine. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluids from the visible follicles of diameter 3~5 mm. The follicular oocytes were cultured in TCM-199 medium containing hormones and 10% ECS for 46~48 hrs in a incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 12~18 hrs with motile capacitated sperm by preincubation of heparin. The results obtained in these experiments were summarized as follows ; 1.The in-vitro maturation and fertilization rate of porcine oocytes co-cultured with uterine fluids in TCM-199 medium were 68.0% arid 55.7%, the rates were higher than of control, 56.5% arid 38.7%. 2. When the in-vitro fertilized oocytes were co-cultured with porcine uterine epithelial cells, the fertilization rate was 60.3%, the rates were higher than that of control, 35.7%. 3. When the in-vitro fertilized oocytes were co-cultured with porcine uterine epithelial cells, the development rate to be blastocyst was 12.4%, the rates were higher than that of control, 9.2%(p<0.05).

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.919-927
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• 1996

In the last few years, methods for in vitro culture of early embryo stages from oocytes matured and fertilized in vitro using suitable cell culture systems have been established. But the factors affecting pregnancy rates following transfer of bovine embryos produced in vitro were not evaluated enough. So this study was performed to investigate the effects of quality and stage of embryos, parity and Corpus Luteum quality of recipients on pregnancy rates following non-surgical transfer of bovine embryos produced in vitro. Oocytes aspirated from small antral follicles of ovaries obtained at a local slaughter house were matured, fertilized with frozen-thawed semen and co-cultured for 6-7 days by utilizing co-culture system with bovine oviduct epithelial cell in vitro. After co-culture, embryos were transfered to recipients on day 7 (estrus=day 0). Recipients were monitored by ultrasonic scanning method or observation for estrus and rectal palpation after 50 days from transfer. The results of this study are follows. 1. Of the 70 recipients, 70%(49 of 70) had not showed estrus sign between day 0 and day 50, but 22.9%(16 of 70) was diagnosed not pregnant. Therefore the overall pregnancy rate of this study was 47.1%(33 of 70). 2. The pregnancy rate of recipients transfered with excellent(66.7%) and good(54.5%) embryos were higher than that of recipients transfered with fair embryos(15.8%) (p<0.05). 3. The pregnancy rate of recipients transfered with morula, compacted morula, blastocyst and expanded blastocysts were 46.2, 55.0, 62.5 and 50.0%, respectively. 4. The pregnancy rates of recipients transfered to heifer and cow were 54.5 and 55.2%, respectively. 5. The pregnancy rates of recipients with CL score I, II(66.7, 63.6%) were higher than those of recipients with CL score III (10%), (p<0.05). Success of transfer of embryos produced in vitro depends on many variables. The important factors identified in this study were the quality of embryos and the CL score of recipient animals after non-surgical transfer of embryos matured, fertilized and cultured in vitro.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.18-33
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• 2002

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.41-48
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• 2013

This study examined the motility of either the unattached(upper) or attached(lower) Hanwoo sperm to bovine oviduct epithelial cell(BOEC) monolayers to determine whether there are any changes in their motility during co-culture. The cleavage and blastocyst development rate were compared among different preincubation methods in-vitro, after oocytes were fertilized in-vitro with Hanwoo sperm on BOEC monolayers. The motility of frozen-thawed sperm in BOEC co-culture group was significantly higher than controls, especially at 5 hours and 6 hours (p<0.05) of incubation, in sperm treatment medium without heparin and caffeine. The motility of frozen-thawed sperm in BOEC co-culture group was significantly higher than controls, especially at 3 hours (p<0.05) and 6 hours (p<0.01), in sperm treatment medium containing heparin and caffeine. The motility of the attached( lower) sperm was significantly higher than the unattached(upper) sperm during co-culture with BOEC at all times(p<0.01 or p<0.05), except for 6 hours. After Hanwoo oocytes were fertilized in-vitro with the sperm that had been co-cultured with BOEC in sperm treatment medium containing heparin and caffeine, we determined the cleavage and blastocyst development rate, according to the preincubation methods. Both the cleavage and blastocyst development rate from 2 hour preincubation group were the highest, but significant difference was not recognized. These results show that BOEC plays an important role on sperm hyperactivation related to capacitation regardless of heparin and caffeine in sperm treatment medium. However, oviduct epithelial cell had no significant effect on the development of embryos after in-vitro fertilization in the presence of added heparin and caffeine in sperm treatment medium.