• Journal of Embryo Transfer
• /
• v.14 no.2
• /
• pp.99-106
• /
• 1999

핵 이식에 공여되는 수핵난자의 효과적인 동결보존을 위하여 한우 성숙난자를 1.0 M dimethylsulfoxide(DMSO) 또는 1.0 M glycerol이 함유된 동결보호제를 이용하여 처리하거나, 동결보호제 처리 후 완만동결법을 이용한 동결융핼르 시행하여 상기 실험처리로 야기되는 투명대 경화현상을 관찰하였다. 도축장 유래의 난소에서 미성숙난자를 채취한 후 10% 소 태아혈청을 함유한 TCM-199을 이용하여 22∼24 시간 동안 체외성숙배양을 이해하였다. 배양후 작출된 성숙난자를 각각의 동결보호제로 처리, 혹은 처리 후 동격융해한 후 protease를 이용하여 투명 대의 경화현상 발생의 빈도를 조사하였다. 또한 동격란을 동결정액을 이용한 체외수정에 공여한 후 정자 침입농도능을 조사하였다. 동결보호제로 처리한 난자에 있어서 보호제의 종류와 관계없이 투명대 경화현상이 유의적 (P<0.05) 으로 증가하였으나 이후의 동결융해 처리에 의한 추가적인 경화현상의 발생은 증가하지는 않았다. 또한 투명대 경화현상의 발생양상을 동결보호제 처리 후 10분 간격으로 측정한 결과 DMSO의 경우 처리후 10분, glycerol의 경우 처리 후 20분 후부터 유의적으로 차를 발견할 수 없었으며, 수정율 및 난자 1개당 침입한 정자의 수는 동결란에서 유의적으로 증가하지 않았다. 본 연구의 결과 동결난자의 투명대 경화현상은 동결보호제 처리과정에서 이미 일어나지만, 이러한 투명대 경화현상이 난자의 동결보존 후 수정능에는 현자한 영향을 미치지 않는다는 사실이 규명되었다.

• Journal of Embryo Transfer
• /
• v.9 no.1
• /
• pp.23-29
• /
• 1994

The long term goal of this research is to develop an efficient procedure for large scale production of genetically identical or cloned animals. To improve nuclear transpalntation efficiency in the rabbit, this study evaluated the age of nuclear recipient oocytes on the different steps of nuclear transplantation. The ovulated oocytes in different ages were collected from the superovulated does by flushing oviducts with Dulbecco's phosphate buffered saline(D-PBS) supplemented with 10% fetal calf serum(FCS) from 13 to 15, 17 to 20 and 23 to 26 hours after hCG injection. The denuded oocytes were used as nuclear recipient cytoplasm following enucleation by micromanipulation. The blastomeres separated from the 8-cell embryos were used as nuclear donor. The enucleated oocytes receiving a blastomere in the perivitteline space were fused in the 0.28 M mannitol solution at 1.5 kV/cm, 60 sec for three times. The fused oocytes were co-cultured with the monolayered rabbit oviductal epithelial cells in TGM-199 solution with 10% FCS for 72 hours at 37$^{\circ}C$ in a 5% $CO_2$ incubator. The cultured nuclear transplant embryos and in vivo developed embryos collected at 72 hours after hCG injection were stained with Hoechst 33342 dye. Their cell numbers were counted under a fluorescent microscope. The results obtained were summarized as follows ; 1. The aged oocytes(20 hrs. post hCG) showed significantly(P<0.05) higher fusionrates(70 ~ 90%) than the recently ovulated oocytes(30.8%) 2. The aged oocytes which were electrically activated and fused at 20 hours developed to blastocyst at significantly(P<0.05) high rate, while none of the recently ovulated oocytes developed to blastocyst. 3. Even though the aged oocytes at 23~26 hours showed higher fusion rate(85.7%), not only they were inadequate to manipulate but also their developmental potential to blastocyst was highly impaired. 4. The developmental potential in vitro of nuclear transplant embryos was significantly retarded than in vivo deveolped embryos.

• Journal of Embryo Transfer
• /
• v.14 no.3
• /
• pp.185-193
• /
• 1999

To improve the efficiency of in vitro production of embryos with follicular oocytes in pig, the recovery rates, in vitro fertilization and development. The results obtained were as fellows: The number of oocytes recovered 37 ovary was 1,365 by aspiration, 1,884 by slicing and 3,830 aspiration post slicing, per ovary was averaged 103.5 aspiration post slicing than 30.7 by aspiration and 50.8 by slicing (P<0.05). The percentage of grade I and II oocytes recovered was 0.05∼0.2% and 1.7∼2.3% respectively(p<0.05). The fertilization rates of ejaculate and epididymis sperm was 83.0 and 83.1%. And cleavaged rate was 60.8 and 69.0% respectively(P<0.05). However, there were no significant differences between sperm sources. The clevage rates of fertilized oocyte was significantly(P<0.05) higher as B.O(92.8%) than TALP (90.1%) or mTBM (80.1%). And in vitro developed to blastocyst rates of mTBM media used for fertilization was significantly (P<0.05) higher as 12.4%, compared with the results using the media of TALP(1.6%) or B.O (0.0%). The embryos developed 2-cell stage after in vitro fertilization were co-cultured with or without POEC and BOEC in NCSU-23 and TCM-199 media. In vitro developed to blastocyst rates was NCSU-23 with POEC(2.3%) or BOEC(1.2%), but in vitro cultured in TCM-199 medium with POEC or BOEC was not developed to blastocyst. The percentage of embryos that developed to morula stage in 0, 50, 100, 200 and 250uM was 16.6, 22.0, 13.5, 19.0 and 22.0%, respectively.

• Journal of Embryo Transfer
• /
• v.18 no.3
• /
• pp.263-267
• /
• 2003

This study was carried out to test the efficacy of pharmacological inhibitors of the cell cycle transition in keeping bovine oocytes at the germinal vesicle(GV) stage and the reversibility of this inhibition. Bovine oocytes were incubated for 22∼24 hrs in the presence of various inhibitors : cycloheximide (2$\mu\textrm{g}$/$m\ell$), 6-DMAP (2 mM), and roscovitine (50$\mu$M). Bovine oocytes cultured with any of the inhibitors were significantly blocked at the GV stage. Reversibility of pharmacological inhibitors was assessed by culturing oocytes an additional 22∼24 hours in inhibitor-free medium. Examination of oocytes revealed that the inhibitory effect was fully reversible and effect of resuming meiotic progression on nuclear maturation varied according to the various inhibitors. This study suggests that cycloheximide, 6-DMAP and roscovitine can be applied to control meiotic arrest and resumption in maturation culture of bovine oocytes in vitro. More investigations are needed to better understand how the cell cycle of oocyte is blocked without problems to future developmental competence.

• Obstetrics & gynecology science
• /
• v.61 no.6
• /
• pp.669-674
• /
• 2018

Objective This study aimed to develop a nomogram that predicts ongoing pregnancy after in vitro fertilization and embryo transfer (IVF-ET) using patient age and serum hormonal markers. Methods A total of 284 IVF-ET cycles were retrospectively analyzed. At 14 days post-oocyte pick-up (OPU), the serum human chorionic gonadotropin (HCG) and progesterone levels were measured. The main predicted outcome was ongoing pregnancy. Results Patient age and serum of HCG and progesterone levels at 14 days post-OPU were good predictors of ongoing pregnancy. The cut-off value and area under the curve (AUC) (95% confidence interval) were 36.5 years and 0.666 (0.599-0.733), respectively, for patient age; 67.8 mIU/mL and 0.969 (0.951-0.987), respectively, for serum HCG level; and 29.8 ng/mL and 0.883 (0.840-0.925), respectively, for serum progesterone level. When the prediction model was constructed using these three parameters, the addition of serum progesterone level to the prediction model did not increase its overall predictability. Furthermore, a high linear co-relationship was found between serum HCG and progesterone levels. Therefore, we developed a new nomogram using patient age and HCG serum level only. The AUC of the newly developed nomogram for predicting ongoing pregnancy after IVF-ET cycles using patient age and serum HCG level was as high as 0.975. Conclusion We showed that ongoing pregnancy may be predicted using only patient age and HCG serum level. Our nomogram could help clinicians and patients predict ongoing pregnancy after IVF-ET if the serum JCG level was ${\geq}5IU/L$ at 14 days post-OPU.

• Korean Journal of Animal Reproduction
• /
• v.20 no.1
• /
• pp.9-17
• /
• 1996

This study was conducted to investigate freezability of in vitro and in vitro matured rabbit oocytes, possibility of NT using frozen-thawed unfertilized oocytes, and NT efficiency by zona-slit micromanipulation. After freezing of in vitro matured oocytes, 33 to 49% of oocytes appeared normal morphology and 1.0M DMSO and 1.5M glycerol showed slightly high survival rate, but there was no difference in survival between two cryoprotectants. Freezability of in vitro matured oocytes was low in 1.5M glycerol and more sensitive to freezing. Efficiency of enucleation and fusion rate in method B was higher than that in method A and no difference in this efficiency was between 3 groups of oocytes in method B. Cleavage rate and developmental capacity to M＋B stage of fused embryos derived from frozen oocytes was greatly lower than that from fresh oocytes, respectively(39.1% : 79.5% ; 3.1% : 19.3%) and there was no difference in cleavage rate between DC voltages in two group oocytes. Additional incubation in cytochalasin B after electrical stimulation did not affect embryo development. In conclusion, it is suggested that enucleation and nucelar transfer by slitting of zona is more effective method in rabbit and that further study on optimum freezing conditions for in vitro matured oocytes is necessary to use as recipient oocytes.

• Clinical and Experimental Reproductive Medicine
• /
• v.27 no.3
• /
• pp.301-305
• /
• 2000

Globozoospermia is a rare type of teratozoospermia. It occurs in 0.1% of all andrological patient's and used to be considered sterile. Globozoospermic patient has 100% round headed spermatozoa, but the spermiogram is normal. The spermatozoa show oval-shape head, the lack of a nuclear envelope, acrosome, and post acrosomal sheath. Objective: To report that a couple with infertility secondary to globozoospermia received ICSI treatment. Material and Method: Case report Results: In the first trial, fertilization was failed. In the second trial, 40% of oocytes were fertilized and all of these embryos were cleaved, but pregnancy did not achieved. In the third trial, sperm injected oocytes were exposed to 10 ${\mu}M$ calcium ionophore for 15 min. All of the injected oocytes were fertilized and proceeded to develop. Triplet pregnancy was achieved after the transfer of six embryos in their third cycle. One embryo vanished and the remaining twins (female) were delivered at 33 weeks of gestation by Caesarean section. Conclusion: This result shows that assisted activation following ICSI may overcome infertility associated with globozoospermia.

• Korean Journal of Agricultural Science
• /
• v.33 no.1
• /
• pp.35-41
• /
• 2006

This study was conducted to investigate the developmental ability of interspecies cloned embryos after nuclear transfer of goat fetal fibroblast cells into porcien oocytes. Recipient porcine and goat oocytes were obtained from slaughterhouse and matured in vitro according to established protocols. Enucleation was accomplished by aspirating the first polar body and cytoplasm and a single donor cell was individually microinjected into vitelline space of the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3M mannitol fusion medium. After electro-fusion, interspecies reconstituted embryos were cultured in PZM-3 for 7 days. In porcine interspecies nuclear transfer with goat fetal fibroblast cells, the cleavage rate of reconstituted embryos were 58.9% which was no significant different from that in porcine nuclear transfer embryos (67.4%). However, the developmental rate into blastocyst stage was 5.4% in interspecies nuclear transfer which was significantly lower than that in porcine intraspecies nuclear transfer (13.6%). When the developmental ability of porcine interspecies nuclear transfer with goat cells was compared with goat intraspecies nuclear transfer, the cleavage rate of embryos were 59.2% and the developmental rate into morular and blastocyst stage was 13.6% in interspecies nuclear transfer which were significantly lower than those in intraspecies nuclear transfer embryos. This result indicated that porcine interspecies nuclear transfer with goat fetal fibroblast cells showed the developmental potential in vitro with lower cleavage and developmental rate compared with intraspecies nuclear transfer.

• Journal of Embryo Transfer
• /
• v.19 no.2
• /
• pp.101-112
• /
• 2004

Chloride($Cl^-$) channels play critical roles in cell homeostasis and its specific functions such as volume regulation, differentiation, secretion, and membrane stabilization. The presence of these channels have been reported in all kinds of cells and even in frog oocytes. These essential role of $Cl^-$­ channels in cell homeostasis possibly play any role in egg homeostasis and in the early stage of development, however, there has been no report about the presence of $Cl^-$­ channel in the mammalian oocyte. This study was performed to elucidate the presence of $Cl^-$­ channels in hamster eggs. When allowing only $Cl^-$­ to pass through the channel of the egg membrane by using impermeant cation such as N-methyl-D-glucamine(NMDG), single channel currents were recorded. These channel currents showed typical long-lasted openings interrupted by rapid flickering. Mean open $time({\tau}o)$ was 43${\pm}$10.14 ms(n=9, at 50 mV). The open probability(Po) was decrease with depolarization. The current-voltage relation showed outward rectification. Outward slop conductance(32${\pm}$5.4 pS, n=22) was steeper than the inward slop conductance(10${\pm}$1.3 pS). Under the condition of symmetrical 140 mM NaCl, single channel currents were reversed at 0 mV(n=4). This reversal potential(Erev) was shifted from 0 mV at 140 mM concentration of internal NaCl(140 mM [Na+]i) to ­9.8${\pm}$0.5 mV(n=4) at 70 mM [Na+]i and 11.5${\pm}$1.9 mV at 280 mM [Na+]i(n=4) respectively, strongly suggesting that these are single $Cl^-$­ channel currents. To examine further whether this channel has pharmacological property of the $Cl^-$­ channel, specific Cl­ channel blockers, IAA-94(Indanyloxyacetic acid-94) and DIDS(4, 4'-diisothiocyan ostillben- 2-2'disulfonic acid) were applied. IAA-94 inhibited the channel current in a dose-dependent manner and revealed a rapid and flickering block. From these electrophysiological and pharmacological resluts, we found the novel $Cl^-$­ channel present in the hamster oocyte membrane. The first identification of $Cl^-$­ channel in the hamster oocyte may give a clue for the further study on the function of $Cl^-$­ channel in the fertilization and cell differentiation.

• Journal of Embryo Transfer
• /
• v.26 no.3
• /
• pp.147-152
• /
• 2011

This study was conducted to examine whether efficiency of oocyte production from superovulated prepubertal goats. Fifteen prepubertal and twenty adult goats, maintained in a pen under natural day length and fed hay ad libitum, were pretreated with progestagen implanted CIDR for 10 days. Superovulation treatment of the goats received twice daily intramuscular injection of a total of 70 mg FSH for 3 days from Day 8 of CIDR. All the gonadotrophin treated goats were injected with 10 mg $PGF_2{\alpha}$ on Day 8 and 400~600 IU hCG in the afternoon on Day 10. Oocytes were recovered by follicle aspiration or oviduct flushing at 35 to 40 h after hCG injection through mid-ventral incision. The in vivo matured oocytes was activated by ionomycin (5 min) and 6-DMAP (3.5~4 h). The activated oocytes were cultured in mSOF medium containing 0.8% BSA at 38.5$^{\circ}C$ in an atmosphere of 5% CO$_2$, 5% O$_2$, 90% N$_2$ for 7~8 days. There was no significant difference in the mean number of CL and in vivo matured and follicular oocytes recovered. But, quality of I + II grade follicular oocytes was lower (p<0.05) in the prepubertal goat (25.0%) than the adults (52.4%). The same results were also observed in the cleavage and blastocyst rate of activated oocytcs. The cleavage and blastocyst rate from prepubertal derived oocytes were lower (p<0.05) in the prepubertal goat (54.5%, 23.3%) than the adult goat (86.8%, 46.6%). Considering overall these results, we suggest that maturation of donor goats is a major factor affecting recovered oocytes quality and in vitro development of activated goat oocytes.