• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.55-62
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• 1994

This study was carried out to test the effects of fluorescein diacetate(FDA 0${mu}ell$/ml, 0.5${mu}ell$/ml, 5${mu}ell$/ml, 10${mu}ell$/ml or 0${mu}ell$/ml, 5${mu}ell$/ml in PBS) treated before culture on the survival of vitrified mouse morulae in vitrification solution(20% glycerol＋glycerol＋10% ethylene glycol＋30% ficoll＋10% sucrose). The results were summarized as follows; 1. The survival rate of FDA-tested fresh mouse morulae after 24 hours culture was over 96%((P4.8) in the control or treatment groups with various levels of FDA. Because the rate of mouse morulae which developed to hatched blastocysts was higher with the various levels of FDA treatment(67%) than control(50%), it was considered that toxicity of FDA did not affect the survival of mouse morulae. 2. When mouse morulae were FDA-tested in FDA 0(control), 0.5, 5, and 10${mu}ell$/ml treatment after vitrification, the development rate to expanded blastocyst were 66, 82, 64 and 76%, and FDA scores were P4.2(84%), P4.7(94%), P4.2(84%) and P3.9(78%), respectively. There were no significant differences between control and FDA treatments, but there were significant difference between 0.5${mu}ell$/ml)94%) and 10${mu}ell$/ml(78%) treatment(P<0.01). 3. The survival rates of cultured mouse morulae according to FDA-scores(P0=non-fluorescence; P1~P5=according to their fluorescence) after vitrification were P5;92%, P4;67%, P3;42% and P2.P0;0%, respectively. 4. Implantation rates of morulae stage embryos cultured into early blastocysts and implanted into uterine hornes vitrification were 14 and 11% embryos treated control(0${mu}ell$/ml) and FDA 5${mu}ell$/ml and the normal fetus development was 2% embryos for both treatments. Results of this percent study indicated that toxicity of FDA does not affect not only the survival of fresh and vitrified mouse morulae but also the development rate and implantation of fetus after transfer as well. The development rates of mouse morulae with the FDA score of P5, P4 and P3 were 92, 67 and 42%, respectively, it was considered that FDA-test was fit for the judge of survival.

• Korean Journal of Animal Reproduction
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• v.15 no.3
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• pp.173-177
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• 1991

In vitro survival of the mouse morulae frozen by vitrification method(Kasai et al., 1990) was investigated in the present study. The embryos were plunged into LN2 directly after exposure to the vitrification solutions(EFS, GFS and DFS). The results were obtained as follows. The viability of morulae after freezing and thawing was high in EFS(96.7∼100.0%) and GFS vitrification solution(93.3∼96.7%), and the lowest in DFS vitrification solution(0.00∼0.03%).

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.35-40
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• 1996

This study was carried out to select the best cryoprotectant and to establish optimal concentration of the cryoprotectant in ultrarapid freezing of mouse 4-cell embryos and morulae, respectively. We investigated survival of ultrarapid frozen embryos according to various cryoprotectants such as glycerol, ethylene glycol, propylene glycol and dimethyl sulfoxide (DMSO). Suvival of the embryos frozen at different concentrations (3.0, 4.0 and 5.0 M) of indivisual cryoprotectant was also tested. Preimplantation developmental rate (96.3%, 83/86) of 4-cell mouse embryos treated with 4.0 M ethylene glycol after ultrarapid freezing and thawing was higher than those of other cryoprotectants (glycerol, propylene glycol and DMSO). In the ultrarapid freezing of mouse morulae, the highest developmental rate (98.8%, 89 /90) of the embryos to blastocysts was shown in the group of 5.0 M glycerol. Thus, these results demonstrate that 4.0 M ethylene glycol and 5.0 M glycerol are optimal for ultrarapid freezing of 4-cell mouse embryos and morulae, respectively.

• Journal of Embryo Transfer
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• v.13 no.1
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• pp.1-9
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• 1998

In order to improve the cryopreservation by vitrification or slow freezing of nuclear transplant rabbit embryos, the effects of factors affecting embryo cryopreservation such as cryoprotectants, equilibration, cooling rate and post-thaw dilution on post-thaw survial and development were determined using intact embryos of morular stage. And the post-thaw development of nuclear transplanted embryos cryopreserved under the optimal conditions examined was compared between vitrification and slow freezing. The cryoprotectant solution used was ethyleneglycol-ficoll-sucrose (EFS) or ethyleneglycol-poly-vinylpyrrolidone-galactose- I (EPG- I ) for vitrification, and EPG- II for slow freezing. To examine the viability of frozen-thawed embryos, the nuclear transplanted embryos were co-cultured in TCM-199 plus 10% FBS with bovine oviduct epithelial cells(BOEC) for 24 hrs and the intact morulae were co-cultured with BOEC for 5 days and 3 days to hatching blastocyst stage in 39 ˚C 5% $CO_2$ incubator. The results obtained were as follows: Following vitrification with EFS, the post-thaw development of rabbit morulae to hatching blastocyst was significantly(P<0.05) higher in compacted stage(82.4%) than in early morular stage(60.0%). The post-thaw development of compacted morulae to hatching blastocyst was similarly high in vitrification with EFS(82.4%), EPG- I (85.0%) and in slow freezing with EPG- II (83.3%). Following vitrification with EPG- I, the post-thaw development of intact rabbit morulae to hatching blastocyst was similar as 78.0% and 85.0% in 1-step and 2-step post-thaw dilution, respectively. The post-thaw development of nuclear transplanted rabbit embryos of compacted morulae stage to hatching blastocyst was similarly 43.6% and 40.0% in vitrification with EPG- Iand slow freezing with EPG- II, respectively. These results indicated that the rabbit nuclear transplant and intact embryos of morulae stage could be well cryopreserved with either vitrification or slow freezing procedure.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.105-111
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• 1994

The effects of human or mouse leukemia inhibitory factor(hLIF or mLIF) were examined as a means of increasing the development of in vitro matured(IVM) and in vitro fertilized (IVF) oocytes into morulae or blastocysts. Cell numbers of blastocysts were also counted using Hochest dye staining. Two-to 8-cell embryos derived from bovine IVM/IVF oocytes were cultured 5 to 6 days in CRI aa with or without mLIF or hLIF. All culture media were contained 3mg/ml bovine serum albumin. In experiment 1, the proportion of embryos developed to morulae and blastocysts in CRI aa containing 5,000U/ml mLIF(37.8%) was slightly higher than those of CRIaa containing 1,000U/ml mLIF(34.6%) and 0 U/ml mLIF(27.4%; P>0.05). In experiment 2, 0, 1,000 and 5,000U/ml of hLIF added to CR1aa media yielded 27.6%, 43.0% and 35.5% morulae and blastocysts, respectively(p>0.05). These were no significant increases in cell number among treatments(p>0.05). These results were indicating that mLIF or hLF can increase the proportion of embryos that develop into morulae and blastocysts without and increase in the cell number.

• Korean Journal of Animal Reproduction
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• v.16 no.4
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• pp.317-323
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• 1993

This study was carried out to study effects of the addition level of acetamide and non-permeable cryoprotectants(Ficoll, sucrose) in VS(20% glycerol＋10% ethyleneglycol) and equilibration time on the survival of vitrified mouse morulae. The results are summarized as follows: 1. When 10, 15 and 20% of acetamide were added to the new vitrification solution(20G 10E), FDA-scores of embryos were 4.4(control), 4.4(10%), 3.6(15, 20%), respectively. The addition of acetamide did not affect the survival of forzen-thawed morulae(P<0.05). 2. The survival rate betwen 5 min(3.5) and 10 min(4.6), 10 min(4.6) and 20 min(3.2) of equilibration in 10% sucrose, and 20 min(3.2) and 5 min(4.0), or 10 min(4.3) in 20% sucrose were significantly different(P<0.05). The highest survival(4.6) rate was obtained in mouse morulae equilibrated in VS(20G 10E) containing 10% sucrose for 10 minutes. 3. FDA-score of morulae frozen in the new vitrification solution containing 0, 10, 20 and 30% Ficoll was 4.5, 4.2, 4.4 and 4.6, respectively and had no significant effect among concentrations of Ficoll(P>0.05). The development rate after culture(24h) was 89%(20% Ficoll) and 93%(30% Ficoll), respectively.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.343-359
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• 1989

To study the effects of ibaraki virus on preimplantation mouse embryos collected from prepubertal ICR and BALB/cByJ mice (30~40days old) by superovulation, zona pellucidaintact(ZPI) or free(ZPF) embryos(n=774) of 4- to 8-cell and morulae were exposed to $10^{5.8}$ $TCID_{50}$ of the virus up to 96 hours. The embryos were examined morphologically by observing the degeneration and hatching rates, and virologically and immunologically by determining the presence of infection with the virus, in addition, the effect of washing the embryos to remove virus possibly attached to was also investigated. The ZPI 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rate than those not exposed, for 96, and for 72 to 96 hours, respectively(p<0.01). The ZPF 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rates than those not exposed, throughout the whole culture hours in vitro (p<0.01). The ZPI 4- to 8-cell embryos and morulae not exposed to the virus showed considerably higher rates of hatched blastocyst than those exposed (p<0.01). The virus infection rates of the ZPF 4- to 8-cell embryos and morulae were significantly higher than those of the ZPI embryos according to cell culture system. The viral antigen was detected exclusively on the zona pellucida of ZPI embryos, while the antigen was evenly distributed in the blastomeres of ZPF embryos by the immunofluorescent assay. In the ZPI embryos exposed to ibaraki virus, the virus was detected in the two times-washing groups, but not in the ten times-washing groups. The results indicated that zona pellucida of murine embryos would provide an effective protection and that ten times-washing of the ZPI embryos previously exposed to the virus was effective to remove virus from the embryos.

• Journal of Embryo Transfer
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• v.11 no.1
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• pp.41-50
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• 1996

This experiment was carried out to investigate the ovarian responses of the ovulation point, ovarian weight and size, the number of ovarian follicles and collected embryos, and to study the effects of the developmental stages (oocytes, 2-4 cell. 8-16 cell and morulae), additional levels of Ficoll (0, 15, 30%) on the survival rate (FDA-test) of rat embryos frozen in vitrification solution (20% glycerol + 10% ethylene glycol + 10% sucrose). Sunanarized results was as follows; 1. The mean ovulation point per head was 7, and the weight of ovaries was 0.03g. The size of ovary was 5.9 mm(L) and 4.6 mm(W), and the number of ovarian follicles over and below 2 mm was 4.7 and 8.7, respectively. The number of the collected embryos per head was 5.5 (79%). 2. 2. The FDA score of embryos frozen in 20 G 10 E 10 S without Ficoll was 2.8 (oocyte), 2.6 (2-4 cell), 3.9 (8-16 cell) and 3.6 (morula), respectively. However, there were no significant differences among treatments. 3. The FDA score of embryos frozen in 20 G 10 E 10 S with 15% Ficoll was 3.4 (oocyte), 4.0 (2-4 cell), 4.7 (8-16 cell) and 4.8 (morulae), respectively (P>0.05). 4. The FDA score of embryos frozen in 20 G 10 E 10 S with 30 % Ficoll was 3.7 (oocyte), 3.2 (2-4 cell), 4.4 (8-16 cell) and 4.4 (morulae), respectively (P>0.05). 5. As shown in the above results, the higher survival rate was obtained in the treatment of 15% Ficoll than that of 30%. And the survival rate (FDA-test)of the oocytes and 2-4 cell stages of the rat embryos was lower than that of 8~16 cell and morulae stages. It was considered that 8-16 cell and morulae could be available for the successful freezing by vitrification of rat embryos with 15% Ficoll except for oocytes.

• Journal of Veterinary Clinics
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• v.2 no.1
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• pp.121-131
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• 1985

Mouse embryos of 8-cell stage and compacted morulae(approximately 16 cells) containing different number of blastomeres were bisected and cultured in vitro to determine the developmental potentials of the divided embryos compared with those of unmanipulated control embryos. The results were as follows. 1. Micromanipulation was performed successfully by means of a simple manipulator which holds a fine glass, needle, without the use of any micro-instruments for support. 2. The percentage of bisected morulae with 7-9 blastomeres that developed to eu-blastocyst was 94.1% while only 64.8% of the bisected 8-cell embryos with 4 blastomeres developed to eublastocysts (p<0.05). 3. The percentage of eu-blastocysts decreased, while that of pseudoblastocysts and trophectodermal vesicle increased as the number of blastomeres decreased in the bisected embryos of the two stages. 4. The time of the blastocoele re-formation of the bisected and control embryos was not significantly different in morulae stage embryos, but it was significantly delayed in the 8-cell stage embryos (Eu-B, Pseudo-B) compared with control embryos (P<0.01, P<0.05 respectively).

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.335-343
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• 1997

The effect of thiol compounds on development and intracellular glutathione(GSH) concentrations of bovine embryos produced by in vitro maturation and in vitro fertilization(IVM/IVF) was examined in CRlaa medium with or without $\beta$-mercaptoethanol(0, 10, 25 and 50$\mu$MME) and cysteamine(0, 25, 50 and 75 $\mu$M). Numbers of cells comprising blastocysts were also counted using double fluorescence stain and the total glutathione levels(oxidized and reduced form) of morula and blastocyst embryos were than measured by an enzymatic method. Following routine IVM/IVF procedures oocytes and zygotes were cultured for 40 to 44h in CRlaa medium. Then 2 to 8-cell embyos had cumulus cell removed and were allotted randomly to the experimental medium. In Experiment 1, the proportion of embryos developing to and beyond morulae stages in 0, 10, 25 and 50 $\mu$M $\beta$-ME was 42.9%, 50.0%, 53.7% and 65.6%, respectively. Fifty $\mu$M $\beta$-ME group was significantly higher than those of any other groups (P<0.05). In Experiment 2, the percentages of embryos developed beyond morulae stages in 0, 25, 50 and 75 $\mu$M cysteamine was 42.9%, 40.4%, 60.0% and 59.2%, respectively. Fifty and 75$\mu$M cysteamine groups were significantly higher than in 0 and 25 $\mu$M cysteamine groups, but all of culture medium containing cysteamine(52.6%) was not significantly difference in control group(42.9%). In Experiment 3, the intracellular GSH concentrations of morulae and blastocyst embryos in 0 and 50 $\mu$M $\beta$-ME was 42.4 pM and 44.9 pM, 49.5 pM and 67.8 pM, respectively. Morulae embryos were not difference, but blastocyst embryos were significantly difference between treatments(P<0.05). In Experiment 4, the intracellular GSH concentrations of morulae in CRlaa with or without cysteamine were 39.8 pM and 45.6 pM, and blastocysts were 59.3 pM and 66.8 pM, respectively. Cell numbers of blastocysts were similar to in all experimental groups. These experiments indicate that thiol compounds can increase the proportion of embryos that developing to and beyond morulae stage and the intracellular GSH concentrations.