• Clinical and Experimental Reproductive Medicine
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• v.50 no.4
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• pp.244-252
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• 2023

Objective: We evaluated the efficacy of the newly developed optimized in vitro culture (OIVC) dish for cultivating preimplantation mouse embryos. This dish minimizes the need for mineral oil and incorporates microwells, providing a stable culture environment and enabling independent monitoring of individual embryos. Methods: Mouse pronuclear (PN) zygotes and two-cell-stage embryos were collected at 18 and 46 hours after human chorionic gonadotropin injection, respectively. These were cultured for 120 hours using potassium simplex optimized medium (KSOM) to reach the blastocyst stage. The embryos were randomly allocated into three groups, each cultured in one of three dishes: a 60-mm culture dish, a microdrop dish, and an OIVC dish that we developed. Results: The OIVC dish effectively maintained the osmolarity of the KSOM culture medium over a 5-day period using only 2 mL of mineral oil. This contrasts with the significant osmolarity increase observed in the 60-mm culture dish. Additionally, the OIVC dish exhibited higher blastulation rates from two-cell embryos (100%) relative to the other dish types. Moreover, blastocysts derived from both PN zygotes and two-cell embryos in the OIVC dish group demonstrated significantly elevated mean cell numbers. Conclusion: Use of the OIVC dish markedly increased the number of cells in blastocysts derived from the in vitro culture of preimplantation mouse embryos. The capacity of this dish to maintain medium osmolarity with minimal mineral oil usage represents a breakthrough that may advance embryo culture techniques for various mammals, including human in vitro fertilization and embryo transfer programs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.433-439
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• 2020

This study, which was designed to improve and increase the utilization of female elk, examined the possibility of collecting their embryos during the non-reproductive period using ultrasound-guided Ovum Pick-Up (OPU) technology. Once follicles in the ovaries of an elk were observed, the embryos were retrieved through the absorption of the follicles using an OPU ultrasound probe. Fifty-seven embryos were retrieved from 85 follicles, giving a retrieval rate of 67.1%. Morphological evaluation of the recovered embryos revealed 14.0% embryos to be in grade A, 19.2% in grade B, 15.7% in grade C, and 50.8% in grade D. The developmental efficiency of the retrieved embryos was also investigated using in vitro maturation, in vitro fertilization, and in vitro culture. After cultivating 28 embryos through in vitro fertilization, 19 embryos were found to be fertilized; the fertilization rate was 67.9%. Four embryos developed to the blastocyst stage, indicating a 14.3% development rate. This study confirmed that the production of fertilized embryos from a seasonal breeder, such as elk, is possible via the ultrasound-guided OPU method. If the efficiency of in vitro fertilization and in vitro culture can be improved through further research, it will help improve the efficiency of elk embryo production through the transplantation of their fertilized embryos.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.209-215
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• 1992

These studies were carried out to overcome 2-cell block and in vitro development to blastocysts in vitro fertilization of mouse embryos. The unfertilized ova were obtained by superovulation in ICR mice of 4 to 6 weeks old. Tyrode's 280 solution was used as basal media, and the pH range of media examined was designed from 6.5 to 7.5 with 0.2 interval and the range of osmolality from 250 to 370 mOsm with 20 interval, and the period of sperm preincubation examined was 30, 60, 120, and 180 minutes. The ova developed to 2-cell embryos after 26hrs of incubation with preincubated sperm were evaluatated as in vitro fertilized ones. The results obtained were summarized as follows: 1. The optimal ranges of pH and osmolality of culture media and of sperm preincubation time for in vitro development of in vitro fertilized ova to blastocyst were pH 7.1 to 7.3, 250 to 350 mosmol and 60 to 180 min, respectively. 2. With the media of pH 7.1, 310 mOsm and sperm preincubation period of 120min in another experiment of large sample size, the in vitro fertilized ova was found 66.5% and the in vitro development of in vitro fertilized ova to blastocyst was found 35.8%. From the above results it was concluded that the optimal conditions of pH and osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOam and 120min, respectively.

• Korean Journal of Animal Reproduction
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• v.17 no.4
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• pp.287-294
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• 1994

This study was to investigate the effects of electrofusion, activation and developmental stage of donor embryos on in vitro development of nuclear transplant bovine embryos. A single blastomere nucleus from 8-cell to morula stage embryos produced by in vitro fertilization(IVF) was transferred into a recipient oocyte enucleated at 23∼25 h after in vitro maturation(IVM) or into a recipient oocyte enucleated and cultured for 14∼15 h. In one experiment the nuclear transplant embryos were subjected to additional activation treatments. Fusion rate of nuclear transplant eggs was high at direct current(D.C) voltages of 1.0 and 1.5 kV/cm 991.5 and 93.3%, respectively), but decreased at 2.0kV/cm (81.8%). Additional activation treatments by electric pulases or 7% ethanol did not affect the cleavage and development of nuclear transplant embryos. Development of nuclear transplant embryos slightly increased by delayed nuclear transfer and fusion (42∼43 h after IVM). With this system, blastocysts were obtained from transfer of 8-cell to morula stage donor nuclei (9.6%∼2.4%). The result of this study suggests that nucleo-cytoplasmic interactins, expecially activation of ooplast are very important for the development of nuclear transplant embryos, and donor cell stage does not affect the development of nuclear transplant embryos.

• Reproductive and Developmental Biology
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• v.30 no.4
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• pp.307-311
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• 2006

The purpose of this study was to determine effects of oxytocin and $interleukin-1{\alpha}$ on in vitro development of bovine embryo cultured with endometrial epithelial and stromal cells isolated from bovine uterus. The expressions of COX-2 mRNA in bovine endometrium were also studied. When embryos were cultured with epithelial cells, the rate of blastocysts was significantly (p<0.05) higher in embryos treated with oxytocin than that of control group. The rate of hatched blastocysts was also significantly (p<0.05) higher in embryos treated with oxytocin than those of two control groups. On the other hand, when the embryos were cultured with stromal cells, the rate of blastocysts were significantly (p<0.05) higher than those of groups treated with $IL-1{\alpha}$, oxytocin and control with stromal cells than that of control group without stromal cells. The rate of blastocysts hatched were also significantly (p<0.05) higher in group treated with $IL-1{\alpha}$ than those of control group without stromal cells and oxytocin group. In another experiment, COX-2 gene was expressed in embryo group treated with oxytocin during the co-culture of embryos with epithelial cells. In contrast, COX-2 mRNA was expressed in group treated with $IL-1{\alpha}$ when the embryos were cultured with stromal cell. This result shows that oxytocin and $IL-1{\alpha}$ were stimulate embryo development in vitro when embryos were cultured with epithelial and stromal cells, and can affect the development of bovine embryos in the uterus.

• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.57-68
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• 1993

This stduy was carried out to find a reliable method for the production of in vitro fertilized embryos having more excellent development capacity and freezability in the rabbit and cattle. The greatest number of rabbit oocytes was recovered 6hrs after HCG injection(P<0.05). The maturation rate in vitro was slightly higher in the oocytes(6-h-oocytes) from 6h than those (8-h-oocytes)from 8 hrs after HCG injection and the beneficial effect of FSH during oocyte maturation was significantly great in the oocytes from large follicles. The cleavage rate into 2-to-6-cell stage was not differ between the 6-h-oocytes and 8h-oocytes, but the cleavage of these oocytes was greatly promoted by FSH addition to maturation medium and the cleavge of 8-h-oocytes matured without FSH was significantly low. The embryo development into 16-cell to morula was not promoted by the co-culture with rabbit oviduct epithelial cells. The freezability by embryo stages was ovidusly high at 4-cell and morula stage in 6-h-oocytes and the viability of 16-cell embryos from 8h-oocytes was similar to that of morula stage. The implantation sites after surgical tranfer of fresh rabbit embryos were not implanted. In bovine experiment, the in vitro development into 16-cell and morula after in vitro maturation and fertilization in the follicular oocytes was slightly improved by the co-culture with granulosa cells compared to that with oviduct epithelial cells and the frozen-thawed viability rate of these embryos ranged from 14 to 40%. The excellent fresh embryos were transferred nonsurgically to 6 recipients, but were not pregnant.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.1-10
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• 1997

The present study was conducted to investigate the influence of embryo cell stage at 18h post-fusion and oocyte preactivation on sebsequent in vitro developmental potential in the nuclear transplant rabbit embryos. The embryos of 16-cell stage were collected and synchronized to G$_1$ phase of 32-cell stage. The recipient cytoplasms were obtained by removing the first polar body and chromosome rnass from the oocytes collected by non-dis-ruptive microsurgery procedure. The separated G$_1$ phase blastomeres of 32-cell stage were injected into non-preactivated recipient cytoplasms. Otherwise, the enucleated recipient cytoplasms were preactivated by electrical stimulation at 18h post-hCG injection and the separated G$_1$ phase blastomeres of 32-cell stage were injected. Mter culture until 20h post-hOG injection, the nuclear transplant oocytes were electrofused by electrical stimulation. The fused nuclear transplant embryos were classified into 3~4-cell, 2-cell and 1-cell stage at 18 hrs post-fusion and cultured until the embryos reached blastocyst stage. The developmental rate to blastocyst stage was significantly (P <0.05) higher in all the reconstituted embryos of 3~4-cell stage(58.0%) than in 2 and icell stage. The developmental rate to blastocyst stage in the embryos of 3~4-cell stage at 18 hrs post-fusion was significantly (P<0.05) higher in the reconstituted without oocyte preactivation(77.8%) than in the oocyte-preactivated embryos (33.3%). These results indicated that the higher rate of in the in vitro development to blastocyst stage might be obtained form the embryos which were reconstituted with nuclear donor of G$_1$ phase and non-preactivated oocyte, and developed more rapidly for 18 hrs post-fusion.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.287-294
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• 2007

The present study was to conducted the sexing efficiency and accuracy of bovine embryo by LAMP (Loop-mediated isothermal amplification) method, the development of the biopsied embryos into re- reformation and the freezability of these blastocysts by slow-freezing and vitrification. In vivo embryos were superovaluted with gonadotropin(Antorin R-10) for 4 days combined with progestrone releasing intravaginal(CIDR) insertion in Hanwoo donors, and in vitro embryos were used blastocyst embryos at Day 7 or Day 8 after post-insemination in vitro. The biopsy of bovine embryo was carried out in a 80μl drop with Ca2+-Mg2+ free D-PBS and the viability of biopsied embryos were evaluated in IVMD medium at over 12 h culture time in 5% CO2 incubator.For embryo sexing, about five or seven blastomeres were isolated from in vitro and in vivo embryos at blastocysts with microblade. and were then subjected to LAMP. The survivability of biopsied embryos were no difference in the development rate to re-formation of blastocysts between in vivo and in vitro embryos(100% and 90% respectively). The rates of sexed embryos were compared according to two groups, the female rate was lower than that the male in the in vivo and in vitro embryos(46% vs, 54% and 40% vs, 60%, respectively). However, there were no difference in the overall sexing ratio between the two groups. The survivability of frozen-thawed sexed embryos were lower in the in vitro than in vivo embryos in the slow-freezing(Group 1) and vitrification method(Group 2), (41.7% vs. 58.8% and 57.1% vs, 77.8. respectively).

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.110-115
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• 1984

These experiments were carried out to obtain the information about the optimal pH osmolality affecting in vitro fertilization of the mouse eggs, to elucidate the 2-cell block to development in vitro and to find out the method of controlling the subsequent embryo development in vitro. pH and osomlality was adjusted by adding NaCl or NaHCO3 to the basic salt solution. In vitro fertilization were carried out by inroducting the cumulus masses to the suspension of epididymal spermatozoa at each pH, osmolality, and 10${\mu}$M-EDTA medium. The results obtained in these experiments were summarized as follows: 1. The fertilization rates in vitro at each medium of 235, 252, 269, 286, 306, 323, 345, 368, 393 mosmol were 15.6, 38.2, 65.7, 75.6, 80.9, 74.3, 58.1, 35.1, 24.3, 11.1%, respectively. 2. The fertilization rates in vitro at each medium of pH 6.1, 6.4, 6.7, 7.0, 7.3, 7.6, 7.9, 8.1 were 11.8, 17.9, 32.4, 61.9, 79.5, 76.7, 53.5, 13.6%, respectively. 3. In case of ICR female x ICR male embryos, the development rate of 2-cell embryos to 4-8 cell embryos was 16.2% at normal medium, but the rate was increased to 49.3% in medium containging 10 ${\mu}$M-DETA; In case of C3H female x ICR male embryos, the development rate was 41.0% at normal medium, but the rate was increased to 71.7% at 10 ${\mu}$M-EDTA-medium.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.170-170
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• 2004

First of all, in vitro production (IVP) of porcine embryos is an important as initial step to improve bio-technical applications such as transgenesis and cloning for xenotransplantation. In recent years, considerable progress has been achieved in the IVP embryos using advanced methods for in vitro maturation (IVM) and fertilization (IVF). (omitted)