• Journal of Embryo Transfer
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• v.14 no.3
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• pp.163-169
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• 1999

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system(modified TALP ; mTALP) on the development of IVM-IVF embryos, and survival of in vitro produced blastocysts after freezing and thawing. Occytes from the slaugheterhous ovaries were matured and fertilized using general protocol. The results obtained were as the following: 1. Survival rates of frozen-thawed blastocysts using 10% glycerol as cryoprotectant was higher in day 7 blastocysts than in Day 8 and 9 blastocysts from co-cultrue system, but survival rate of frozen-thawed blastocysts was higher in Day 10 blastocysts than in day 8 and 9 blastocysts from defined culture system. Regardless of their age, survival rate of frozen-thawed blastocysts was significantly higher (p<0.05) in co-culture system than in defined culture system. 2. The cell number of blastocysts was significanlty higher (p<0.05) in Day 7 blasotcysts than in Day 8 and 9 blastocysts from co-cultures, but the cell number of blsstocysts was significantly higher (p<0.05) in Day 10 blastocysts than in Day 8 and 9 blastocysts from defined culture system. Regardless of the culture system, blastocysts with higher cell number showed higher survival rates after freezing and thawing.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.265-269
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• 2007

This study was conducted to investigate the efficacy of vitrification procedure for the cryopreservation of porcine oocytes and the utilization of vitrified oocytes as recipient cytoplasts for somatic cell nuclear transfer (NT), and observed that porcine oocytes are evaluated by pronuclear formation, and parthenogenetic development. Single fetal donor cells were deposited into the perivitelline space of vitrified enucleation oocytes, followed by electrical fusion and activation. NT embryos were cultured in NCSU-23 medium supplemented with 5% FBS, at $38.5^{\circ}C$ in 5% $CO_2$ and air. 1. When the developmental rates of the oocytes after being culture for $0{\sim}10$ hours vitrified with EDS and ETS were 42.0%, 38.0%, respectively. This results were lower than the control group(62.2%). 2. When the developmental rates of the oocytes after being culture for $0{\sim}10$ hours vitrified-thawed with sucrose and glucose, 5% PVP, NCSU-23 supplemented with 10% FBS were 33.3%, 25.9%, respectively. This results were lower than the control group(55.6%). 3. The fusion and development to the blastocyst stage between the NT embryos constructed with the vitrified and non-vitrified oocytes were significant differences. Developmental rate of oocytes and NT embryos constructed with the vitrified or non-vitrified oocytes were $13.0{\pm}2.4%\;and\;23.2{\pm}2.4%$, respectively.

• Journal of Embryo Transfer
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• v.30 no.1
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• pp.17-21
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• 2015

Alteration in ion channel or transporter expression levels affects cell volume which is produced by movement of water and ion across the plasma membrane. In particular, aquaporin (AQP) channels among ion channels play a crucial role in movement of water across the cell membrane. This study was performed to identify whether AQP expression is changed in bovine follicular cystic follicles using microarray, RT-PCR and Western blotting analyses. In microarray data, AQP4 expression was decreased, whereas AQP7 was increased in cystic follicles. Additional experiments were focused on the AQP7 expression increased in cystic follicles. The microarray data was confirmed by semi-quantitative polymerase chain reaction (PCR) and Western blot analysis. AQP7 mRNA and protein expressions were significantly increased in the cystic follicles (p<0.05). Application of estrogen ($10{\mu}g/ml$) to bovine ovarian cells showed a trend of increase in AQP7 expression. From these results, we suggest that the increase in AQP7 expression in cystic follicles may play an important role in movement of water in bovine ovary. In addition, AQP7, a aquaglyceroporin permeating water and glycerol, could be a good target in development of methods for the cryopreservation of bovine ovary.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.129-136
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• 2002

The purpose of this study was to investigate the comparison of viability of bovine blastocysts following glass micropipette (GMP) vitrification and the possibility of production of Korean Native Cow ("Hanwoo,"Bos taurus coreanae) following embryo transfer into Mongolia cows (Bos taurus mongolian). The embryos of Korean Native Cow were produced by IVMFC or superovulation methods in Korea, cryopreserved by GMP vitrification, and subsequently trans-ported to Mongolia. The recipient cows were synchronized using a CIDR plus and prostaglandin $F_2\alpha$($PGF_2\alpha$) treatment. To produce in vivo embryos, seven cows were superovulated using FSH and PGF$_2$／sub $\alpha$／ treatment. A total of 64 blastocysts ( $9.1\pm2.94$ per cow) were collected. In vitro embryos were produced using a defined culture system which cleaved in 80.1％ ova (174／217), and developed to blastocyst stage embryos of 40.8％ (71／174). The post-thaw survival rate of in vivo blastocysts (93.7％; 45／48) was significantly higher than that of in vitro blastocysts (82.5％; 52／63, P＜0.05). Embryo transfer was carried out using 8 Mongolian recipient cows and 2 post-thaw blastocysts per recipient. Five of 8 recipients were found pregnant at Day 60 but one abortion occurred by Day 240. Two of offspring were produced from the Mongolian cows at 275 days after embryo transfer. These results indicated that a GMP vitrification method could be used as a cryopreservation technique for in vivo or in vitro bovine blastocysts and produced effectively a Korean Native Cow following embryo transfer into a Mongolian recipient cow.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.2
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• pp.121-129
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• 2001

Objective: The aim of this study is to compare the efficiency of a method for the cryopreservation of mouse blastocyst.. Methods: Mouse embryos were obtained at 2-cell stage and cultured to blastocyst stage in T6 medium supplemented with 10% fetal bovine serum. Morphologically normal blastocysts were collected and randomly divided to one control and four experimental groups. In control group, blastocysts were cultured in vitro continuously for additional two days. In group 2, blastocysts were exposed to vitrification solution (ethylene glycol) only without cryopreservation (exposure only group). In group 3, 4 and 5, blastocysts were cryopreserved by slow-freezing procedure with glycerol (slow-fteezing group) or by vitrification procedure using EM grids (EM grids group) and cryoloop (cryoloop group), respectively. Frozen blastocysts were thawed and cultured for additional two days. Twenty four hours after thawing, some blastocysts were fixed and stained with Hoechst 33342 (bisbenzimide) and the number of nuclei in each blastocysts were counted to confirm the survival of bias to cysts in experimental groups. Results: Survival rate and hatching rate of the blastocysts in slow-freezing group (24 h: 72.4% and 66.0%, 48 h: 63.2% and 64.6%) and EM grids group (24 h: survival rate 77.3%, 48 h: 70.1% and 71.4%) were significantly lower ($X^2$-test p<0.05) than those of control group (24 h: 93.4% and 86.0%, 48 h: 88.5% and 90.7%). In contrast, the survival rate and hatching rate of the blastocysts in cryoloop group (24 h: 84.1% and 84.1%,48 h 79.3% and 87.7%) is well compared with those in the control group. The mean (${\pm}SD$) cell number of blastocyst in the exposure only ($89.2{\pm}11.5$), EM grids ($85.0{\pm}10.3$) and cryoloop ($89.0{\pm}11.0$) groups, except slow-freezing group ($79.0{\pm}10.0$), were not significantly different from that of control group ($93.1{\pm}13.9$) 24 h after thawing (Student's t-test). Conclusion: This study demonstrates that higher survival rate of vitrified-thawed mouse blastocyst can be obtained using cryoloop as the embryo container at freezing rather than slow-freezing or vitrification using EM grids. The results of this study suggest that vitrification using cryoloop (with ethylene glycol) may be a preferable procedure for mouse blastocyst cryopreservation and could be applied to the human blastocyst cryopreservation.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.125-128
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• 2010

Culture conditions were established for high frequency plant regeneration via somatic embryogenesis from cell suspension cultures of Nymphoides coreana. Zygotic embryos formed pale-yellow globular structures and calluses at a frequency of 85.6% when cultured on half-strength Murashige and Skoog (MS) medium supplemented with 0.3 $mg\;l^{-1}$ of 2,4-D. However, the frequency of pale-yellow globular structures and white callus formation decreased slightly with an increasing concentration of 2,4-D up to 10 $mg\;l^{-1}$ with the frequency rate falling to 16.7%. Cell suspension cultures were established from zygotic embryo-derived calluses using half-strength MS medium supplemented with 0.3 $mg\;l^{-1}$ of 2,4-D. Upon plating onto half-strength MS basal medium, over 92.3% of cell aggregates gave rise to numerous somatic embryos and developed into plantlets. Regenerated plantlets were successfully transplanted into potting soil and achieved full growth to an adult plant in a growth chamber. The high frequency plant regeneration system for Nymphoides coreana established in this study will be useful for genetic manipulation and cryopreservation of this species.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.141-149
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• 1997

This study was carried out to investigate the effect of vitrification and slow freezing methods on the post-thaw developmental rate of rabbit zygotes. After exposing rabbit zygotes in EFS solution for 0.5, 1, 2, 3 and S min at room temperature, they were washed with 0.5 M sucrose solution, D-PBS and TCM-199 and then cultured in TCM-199 plus 10% FBS with bovine oviduct epithelial cells(BOEC) to examine whether the cryoprotectant induced injury during the various exposure periods. The embryo development rates to hatched blastocyst after exposing in EFS solution for 3 and 5 min(40.0 and 16.7%) were significantly lower than in 0.5, 1 and 2 min(63.0, 72.0 and 54.5%), respectively. The post-thaw development rates to hatched blastocyst were significantly(P<0.05) higher in in vivo morula with intact mucin coat(85.2%) and mucin seperated morula(77.8%) than those of in vitro morula(58.5%) and zygote(5.9%), hut no difference was shown between in vitro morulae and mucin separated morula. The cryoprotectant dilution procedures showed no effects on the post-thaw development rates to hatched blastocyst under the present culture conditions. The post-thaw development to hatched blastocyst in the rabbit zygotes was not significantly different between the slow freezing(12.8%) and vitrification(5.9%). These results indicated that the rabbit frozen zygotes could he successfully developed in vitro to hatched blastocysts, though their developmental rate was very low, compared with morula stage embryos, in either vitrification or slow freezing procedure under the present conditions.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.394-400
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• 1998

Cryopreservation of embryos by vitrification is a simple method to preserve bovine embryos for subsequent embryo transfer, but embryonic viability after vitrification has been inconsistent and low compared with conventional slow freezing. The aim of the present study is to examine the effect of serum or serum albumin in a vitrification solution and epidermal growth factor(EGF) or fibroblast growth factor(FGF) on in vitro viability of bovine blastocysts frozen by vitrification. Bovine blastocysts were produced by in vitro maturation, fertilization of follicular oocytes and culture of embryos in a synthetic oviduct fluid medium(SOFM) containing BSA and 19 essential and nonessential amino acids. Blastocysts with excellent or good morphology were selected at 7 or 8 days after culture and utilized for vitrification. In experiment 1, blastocysts were vitrified in a solution containing semi-fetal calf serum(SFCS) or BSA(5 or 10mg/ml) and then their subsequent viabilities were examined by culturing thawed embryos in a SOFM containing BSA and 19 amino acids. Effect of EGF or FGF added to a SOFM containing polyvinyl alcohol(PVA) on the viability of vitrified-thawed blastocysts was investigated in experiment 2. BSA added at 5 or 10mg/ml to a vitrification solution showed significantly higher(p < 0.05) developmental rate to expanded and hatching blastocysts than SFCS, but there was no significant difference in the developmental rate to hatched blastocysts after thawing. Supplementation of a culture medium with EGF and/or FGF significantly increased(p < 0.05) embryo development to expanded blastocysts compared with control but showed no beneficial effect on the development to hatching or hatched blastocysts. Coculture of thawed embryos with granulosa cells in a TCM 199 containing 10% fetal calf serum(FCS) showed the highest developmental rate to expanded, hatching and hatched blastocysts among the groups tested. In conclusion, supplementation of a vitrification solution with BSA at 5mg/ml and culture of thawed blastocysts in a medium containing EGF and/or FGF can improve in vitro viability of bovine blastocysts frozen by vitrification.

• Journal of Embryo Transfer
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• v.9 no.2
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• pp.173-180
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• 1994

The present experirnents on cryopreservation were carried out to investigate effect of solution toxicity, equilibration time and cell stages on the post-thaw survival of mouse morulae and blastocyst embryos cryopreserved by vitrification in EFS solution. The mouse embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen and thawed rapidly. After the mouse morulae embryos were exposed to EFS solution for 2 and 5 ruin. at room temperature and then they were washed in 0.5 M sucrose solution and basal mediurn(D-PBS + 10% FCS), they were cultured to examined cryoprotectant toxicity induced injury during exposure, most of embryos developed to expanded blastocysts(100 and 90.0%). However, when the exposure time was extended to 10 and 20 min, these development rates dropped dramatically in 10 ruin. (75.0%) and 20 ruin. (4.5%), respectively. When the compacted morulae were vitrified in EFS solution after equilibration for 2 and 5 min, the embryos have developed to normal blastocyst following thawing, washing and culture processes was 89.3 and 89.6%. However, when the exposure time was expanded to 10 ruin, this survival rate dropped to 68.8%. When the blastocyst were vitrified in EFS solution after equilibration for 2, 5 and 10 minutes, the survival rate of embryos which developed to normal blastocyst following thawing and culture processing were 58.5, 46.7 and 22.4%, respectively. The optimal time of equilibration of mouse morula and blastocysts in EFS solution seemed o be 2 and 5 ruin.

• Journal of Embryo Transfer
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• v.25 no.4
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• pp.291-295
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• 2010

Four estrus-induced Himalayan tahrs (Hemitragus jemlahicus) were inseminated with frozen-thawed semen by laparoscopic or transcervical insemination techniques with no regard to the site of ovulation in non-breeding season. In June and July, 2009, estrus was synchronized by Eazi-Breed $CIDR^{(R)}$ (Controlled internal drug release; Pfizer Animal Health, New Zealand) insertion for 16 days and PG 600 (PMSG 400IU, hCG 200 IU; Intervet, Netherlands) injection (IM) a day before removing $CIDR^{(R)}$. Forty eight hours later, laparoscopic or transcervical insemination was done to each of two tahrs under anesthetic condition inducted by ketamine (1.5 mg/kg) and medetomidine (0.09 mg/kg). For examination of estradiol and progesterone, blood was collected right before $CIDR^{(R)}$ insertion, PG 600 injection, $CIDR^{(R)}$ removal and insemination. Estradiol levels of four tahrs (No. 1, 2, 3, 4) before $CIDR^{(R)}$ insertion and insemination were 13.3, 8.8, 14.3, 12 pg/ml and 23.5, 25.5, 21.1, 11.5 pg/ml, respectively. Progesterone levels of four tahrs (No. 1, 2, 3, 4) before $CIDR^{(R)}$ insertion and insemination were 1.8, 0.05, 0.63, 0.61 ng/ml and 1.03, 0.37, 1.48, 2.12 ng/ml. Except for No. 4 tahr, cervices showed cervical mucus and opened enough to penetrate with embryo transfer gun sheet usually used for cows. Therefore, No.4 was laparoscopically inseminated together with No. 1. In conclusion, none of four Himalayan tahrs was pregnant. However, we proved that estrus could be induced by CIDR and PG 600 injection in non-breeding season, and laparoscopic or transcervical insemination with frozen-thawed semen could be one of assisted reproductive techniques in Himalayan Tahr.