• Asian-Australasian Journal of Animal Sciences
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• v.8 no.4
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• pp.317-320
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• 1995

The effect of co-culture with cumulus cells and granulosa cells during maturation and development on in vitro developmental potency of follicular oocytes was examined. TCM-199 supplemented with 15% FCS and hormones was used as maturation medium. Sperm from frozen semen was capacitated in modified mTALP medium containing 0.3% BSA, $10{\mu}g/ml$ heparin and 5 mM/ml caffeine. The fertilized embryos were co-cultured on monolayer of cumulus cells or granulosa cells in TCM-199. The embryo co-cultured with cumulus cells showed higher percentage of embryo developed to morula and blastocyst (73.3%) than the embryo co-cultured without cumulus cells (30.8%). The percentage of oocytes developed to morula and blastocyst among cleaved oocytes was significantly (p < 0.05) higher in the oocytes co-cultured with cumulus cells during development (62.4%) than in the oocytes co-cultured with granulosa cells during maturation and with cumulus cells during development (52.3%), and in the oocytes co-cultured with granulose cells during development (52.8%). The results of this study indicate that co-culture of in vitro fertilized embryos with cumulus cells in the development medium increased the rate of embryos developed to morula and blastocyst among cleaved oocytes.

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.19-23
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• 1983

Present studies were conducted to investigate the developmental stage and the location of embryos in the reproductive tract at various times after ovulation, the morphologically normal after thawing of embryos preserved in liquid nitrogen, and the survival after transferring frozen-thawed embryos. The results obtained were as follows: 1. Embryo stage and location in the reproductive tract after hCG administration. For the investigation of embryo stage and location in the reproductive tract after ovulation, rabbits were laparotomized at 24, 40, 48, 72 and 120 hrs post hCG injection, simultaneously with mating. the oviducts and uteri were flushed out with PBS medium containing 50% rabbit serum, respectively. 1) Most of embryos was remained in the oviduct within 48 hrs, with the lapse of time, embryos were started to move to uterus and shifted in uterus at 72 hrs after hCG injection. 2) The representatives of embryos stage collected at 24, 40, 48, 72 and 120 hrs were 1-cell(60.4%), 8-cell to early morula (52.3, 39.3%), late blastocyst (95.5%) stages, respectively. 2. Morphological normality and survival of the frozen-thawed embryos. For the evalution of the quality and viability on the frozen-thawed embryos, immediately after thawing, embryos were assessed by morphologically normal under a dissecting microscope, and a further test of frozen-thawed embryos was made by transferring the morphologically normal embryos to the uteri of recipient rabbit induced pseudopregnancy by the injection of hCG at the time of hCG injection in donor rabbits. 1) The propotions of embryos which a, pp.ared morphologically normal was higher when 8-cell (85.7%) and morula(90.5%) were used for freezing than when 4-cell (66.7%) and blastocyst (75.8%) were used. 2) Preganacies were observed at Day 15 after transfer of frozen-thawed 8-cell (7/13), morula (19/42) and blastocyst (3/19) but not after transfer of embryos at 4-cell stage.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.27-35
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• 1986

As a preliminary experiment to establish the process on the sexing of mouse embryos by chromosomal analysis, present studies were carried out with inbred (ICR, C57BL) and F1 hybrid [(ICR${\times}$C57BL) = F1 ${\times}$ ICR] mice to investigate the blastomere numbers and mitotic indices (M.I.) to the developmental stage of embryos recovered, the optimum periods of anti-mitotic agent administration, the successful rates of sexing and sex-ratio. The results obtained were summarized as follows: 1. The blastomere numbers (mean${\pm}$S.E.) of the morula and blastocyst were 18${\pm}$0.4 and 54${\pm}$0.7, respectively. 2. Whereas the M.I. of F1 hybrid (16${\pm}$0.2%) was higher than that fo inbred ICR (15${\pm}$0.1%) and C57BL (12${\pm}$0.6%) in the different strains, the morula (7${\pm}$0.6%) was higher than that of blastocyst (6${\pm}$0.4%) in the case of embryo stages. 3. Following to anti-mitotic agents treated, the M.I. of embryos cultured with Colcemid (17${\pm}$1.1%) was superior to that fo embryos cultured with Velban (12${\pm}$0.9%) and the Colcemid injection (7${\pm}$0.4%). 4. The successful rate of sexing in the blastocyst (38.7%; 124/320) was superior to the morula (35.9%; 52/145), and the F1 hybrid (48.1%) was higher than that of inbred ICR (42.4%) and C57 BL (28.2%). 5. In the successful rate of sexing to the methods of administration, the embryos cultured with Colcemid (46.0%) was superior to that of embryos cultured with Velban (39.0%) and the Colcemid injection (38.8%). 6. Of 98 embryos sexed after culture with Colcemid, 89(90.8%) were observed between 2 and 4 hrs. In the case of Velban treatment, 83.1% (74/89) was observed between 2$\frac{1}{2}$ and 4$\frac{1}{2}$ hrs. 7. Out of 761 prepared embryos it was possible to sex 311; 157 were male and 154 were female, i.e.a sex-ratio of 50% a, pp.oximately.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.96-102
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• 1995

This study was conducted to investigate the effect of energy source on development of in vitro matured and fertilized porcine 2-cell embryos. The effects of glucose and phosphate for in vitro development of porcine 2-cell embryos were determined using modified BMOC-II medium. The results obtained are as follows. 1. In the absence of glucose and phosphate in the culture medium, 15.2% of porcine embryos developed 4-cell stage or further but morula formation was completely blocked. 2. The addition to 5mM glucose in the culture medium decreased rate of embryo reached 4-cell stage or further but increased morula stage as compared with addition to 0mM and 2.5mM glucose, regardless of the presence of phosphate. The addition to glucose in the culture medium without phosphate increased rate of embryo reached 4-cell stage or further and morula stage as compared with both addition to glucose and phosphate, regardless of added glucose concentration.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.62-68
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• 1995

This study was carried out to examine splitting, developmental capacity and rapid freezing of blastomeres separated from 2-, 4-, 8-cell and morula from porcine embryos. The results obtained in this study were summerized as follows : 1. The successful splitting rate by pronase was 85.7% in 2-cell embryos(average splitting rate, 68.0%), and by manipulator was 76.6% and 74.3% in 2- and 4-cell embryos. 2. The developmental capacity rates of splitted embryos by the pronase treatment were 24.1%, 20.4%. 25.5% and 26.6% in 2-, 4-, 8-cell and morula, and by manipulator were 36.4%, 39.5%, 36.1% and 41.9%, respectively. 3. The successful results of in vitro culture after frozen-thawed of splitted embryos were 16.1%(glycerol) in 2-cell, 16.7%(DMSO) in 4-cell and 27.6%(ethyleneglycol) in morula, respectively.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.253-257
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• 2009

To enhance the embryo preservation technology and better application of embryo transfer technique to the field (dairy science or animal reproduction. etc.), we examined the viabilities of bovine embryos produced in vitro and in vivo after cryopreservation according to their developmental stage and thawing temperature. Bovine embryos from in vivo/vitro fertilization (Hanwoo) were examined at day 7, 8, and 9. Survival rates and total cell numbers of in vivo fertilized embryos were as follows: morulae 68.8% and $67\;{\pm}\;6.0$; blastocysts 80.5% and $120\;{\pm}\;10$; expanded blastocysts 77.4% and $138\;{\pm}\;9.7$, respectively. Rates of embryo development for blastocysts and expanded blastocysts after thawing were significantly higher than that of morula stage embryos (p<0.05). While survival rates of in vitro fertilized embryos according to developmental stage showed no significant difference among groups (morula 67.9%; blastocyst 74.3%; and expanded blastocyst 79.4%), total cell numbers were significantly lower than those of other groups (morula $64\;{\pm}\;5.9$; blastocyst $116\;{\pm}\;8.7$; and expanded blastocyst $135\;{\pm}\;9.1$) For the viability according to thawing temperature, survival rate was higher in $37^{\circ}C$.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.635-641
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• 1995

The purpose of this study was to investigate the effects of developmental stage and equilibration time on survival of rabbit embryos following freezing by vitrification. Adult New Zealand White female rabbits were superovulated with PMSG and hCG. The 8-cell stage embryos were collected from 40 to 45 hours after hCG injection by flushing oviducts with Dulbecco's phosphated buffered saline and in vitro cultured in TCM-199 containing 10% fetal calf serum(FCS). Each embryos developed in vitro to 16-cell, compact morula and blastocyst was cryopreserved and cultured following thawing to examine their developmental potential to expanded blastocyst stage in vitro. The frozen-thawed-cultured embryos were stained with Hoechst 33342, and their nuclei were counted using a fluorescence microscope. On the toxicity test of EFS solution as cryopreservation, the survival rates of 8-cell stage embryos was decreased in reverse to increasing of exposure time over 5 minutes. The post-thaw survival rates of embryos on equilibration times was significantly(P<0.05) higher for 2 min. than for 5 or 10 minutes. From morula to blastocyst of rabbit embryos was more suitable than 8-cell stage for cryopreservation by vitrification. The higher post-thaw survival rate of embryos can be achieved by keeping the cryoprotectant at $4^{\circ}C$ than at $20^{\circ}C$. The mean number of nuclei per embryo following freezing by vitrification and in vitro culture to expanded blastocyst at compacted morula and blastcyst was not significantly differ from fresh blastocyst.

• Journal of Embryo Transfer
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• v.20 no.2
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• pp.105-112
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• 2005

The present study was conducted to examine some factors affecting in vitro development of oocytes from somatic cell nuclear transfer (SCNT) in Korean native goats. Recipient oocytes were surgically collected after superovulation by using CIDR and FSH, PMSG, hCG and estrous synchronization in Korean Native goats. For nuclear transfer, the fibroblasts from caprine ear cells and fetal fibroblasts were surgically harvested and were cultured in vitro until cell confluency in serum-starvation condition (TCM-199 + $0.5\%$ FBS) for 3 to 5 days. The zona pellucidae of matured oocytes were partially drilled by laser irradiation. A single somatic cell was individually transferred into each enucleated oocyte. The reconstructed oocytes were then electrically fused and activated. Activated NT embryos were cultured in mSOF medium supplemented with $0.8\%\;BSA\;6\~7\;day\;at\;39^{\circ}C,\;5\%\;CO_2,\;5\%\;O_2,\;90\%\;N_2$ in air. There were no significant difference in the number of embryos cleaved and 4-cell development between the fibroblast nuclei from mature ear cells and fetal cells, but the rate of 8-cell development was higher (P<0.05) in ear cells $(40.5\%)$ than in fetal cells $(55.5\%)$. However, the embryo development to morula or blastocyst was not significantly different between both the groups$(6.7\%\;vs\;16.0\%)$, respectively. The number of embryo cleaved $(79.0\%)$ were higher (P<0.05) in the oocytes activated with ionomycin+6-DMAP than in the oocytes activated electrically $(9.5\%)$. The development of fused embryos to morula or blastocyst was found $15.6\%$ in ionomycin+6-DMAP, but no morula or blastocysts were developed in electrical stimulation. The development rate of SCNT embryos to morula or blastocyst was love. (P<0.05) in SCNT embryos $(19.0\%\;vs\;0.0\%)$ than that in parthenotes $(66.1\%\;vs\;59.1\%)$. In the parthenotes, the cleavage rate and development to morula or blastocyst were significantly higher (P<0.05) as $86.8\%\;and\;50.0\%$ in ovulated oocytes than in follicular oocytes $(69.0\%\;vs\;23.6\%)$, respectively. These results suggest that some factors Including superovulation treatment, oocyte source, maturation of follicular oocytes, activation method and culture condition may affect in vitro developmental capability of embryos produced by somatic cell nuclear transfer in Korean Native goats, and the fusion rate be greatly low compared with other species.

• Journal of Embryo Transfer
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• v.9 no.2
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• pp.145-152
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• 1994

The suitable electric stimulation is essential for activation and fusion of oocytes before or after nuclear transplantation The present study was undertaken to determine the optirnal condition for the parthenogenetic activation of in vitro rnatured(IVM) bovine oocytes by electric stimulation. Different direct current(DC) electric voltage of 1.0, 1.5 and 2.0 kV/cm and pulse duration of 30, 60 and 120 $\mu$sec were applied to the JVM nocytes in 0.3 M mannitol solution containing each 100 $\mu$M CaCl$_2$ and MgCl$_2$. IVM occytes at 24, 28 and 32 hours Post-maturation(hpm) were also electrically stimulated at 1.5 kV /cm, for 60 $\mu$ sec. The stimulated nocytes were then co-cultured in TCM-199 solution containing 10% fetal calf serum with bovine oviductal epithelial cells for 7~9 days in a 5% $CO_2$ incubator at 39$^{\circ}C$ ~ Their activation and in vitro development to morula and blastocyst were assessed under an inverted microscope. The higher activation rates 62.8 and 63.4% and in vitro de- velopment rates to morula and blastocyst 5.1 and 10.9% were shown in the oocytes stimulated at the voltage of 1.0 and 1.5 kV/cm than 2.0 kV/cm, respectively. No signifi- cantly(P<0.05) different activation rate was shown in JVM oocytes stimulated for 30, 60 and 120 $\mu$sec, but developmental rates to morula and blastocyst was significantly(P<0.05) higher in the oocytes stimulated for 30 $\mu$sec(6~3%) and 60 $\mu$sec(10~0%) than 120 $\mu$sec(0~ 0%). The aged oocytes at 28 and 30 hpm showed significantly(P<0.05) higher activation rates(72~7 and 79.7%) than the oocytes at 24 hpm(50~9%)~ Also, their developmental rates to morula and blastocyst were significantly(P<0.05) higher in the nocytes at 28(14.3%) and 32 hpm(15.9%) than 24 hpm(3.6%). From these results, it can be suggested that the optimal electric stimulation for IVM bovine occytes is a DC voltage between 1.0 and 1.5 kV/cm, pulse duration of 30 or 60 $\mu$sec, and the optimal age of IVM oocytes for electric activation is at 32 hpm.

• Clinical and Experimental Reproductive Medicine
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• v.14 no.2
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• pp.93-100
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• 1987

To determine the effect of calcium on the preimplantational development of mouse two-cell embryo, the various concentrations of calcium were added into the culture media and the rate of blastocyst formation was observed. Also, to examine the effect of trifluoperazine, an inhibitor of calmodulin which is involved in the several intracellular calcium functions, embryos were cultured for 48 hours at the various concentrations of this inhibitor. An additional 24 hour culture was done to examine the effect of this drug on the transformation from morula to blastocyst. The results are as following ; 1. About 1.71mM of extracellular calcium is adequate for blastocyst formation and the higher concentrations of calcium (3.43mM and 8.55mM) do not affect on the blastocyst formation and the degenerating rate. 2. Trifluoperazine $100{\mu}M$ presents the inhibitory effect on the blastocyst formation while $1{\mu}M$ and $10{\mu}M$ do not so. 3. After an additional 24 hour culture, there is transformation of morula to blastocyst and the degenerating rate of embryo is increased all together.