• Journal of Embryo Transfer
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• v.23 no.4
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• pp.269-274
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• 2008

The purpose of this study was to determine the effects of Taxol pre-treatment to in vitro matured bovine oocytes, and sucrose and trehalose added to vitrification solution on spindle morphology and embryonic development following cryopreservation. Bovine oocytes were collected from ovaries and matured in tissue culture medium 199 (TCM 199) supplemented with 10% Fetal Bovine Serum (FBS), 0.05ng/ml epidermal growth factor, 0.01 IU/ml luteinizing hormone and $1{\mu}g/ml$ estradiol for 22h in $39^{\circ}C$, 5% $CO_2$, TCM 199-HEPES containing 20% FBS was used as basic medium (BM) to prepare vitrification solution. Oocytes were pre-treated with $1\;{\mu}M$ Taxol in maturation medium for 15 min prior to vitrification. Oocytes were exposed to 1.6 M ethylene glycol (EG) and 1.3M dimethyl sulfoxide (DMSO) in BM and then were exposed to 3.2 M EG, 2.6 M DMSO and 0.5 M sucrose in BM or 3.2 M EG, 2.6 M DMSO and 0.5 M trehalose in BM. Oocytes with cumulus cells and oocytes without cumulus cells were considered as control 1 and control 2, respectively and held in TCM 199-HEPES at $39^{\circ}C$. Oocytes were frozen using modified solid surface vitrification and were stored in cryotubes in liquid nitrogen for more than 1 week. Frozen oocytes were thawed in TCM 199-HEPES containing 0.5 M, 0.25 M and 0.1 M sucrose in BM for 2 min, respectively or 0.5 M, 0.25 M and 0.1 M trehalose in BM for 2 min, respectively. Immunoflurorescence staining of oocytes was performed to assess spindle morphology and chromosome configuration of oocytes. The rates of cleavage and blastocyst were examined following in vitro fertilization. Normal spindle morphology rate of oocytes pre-treated with Taxol prior to vitrification was not higher than that of other vitrified groups. Taxol pre-treatment did not increase cleavage and blastocyst formation rates, although control groups showed significantly higher rates (p<0.05). Percentages of normal spindle and embryonic development were not significantly different among vitrified groups regardless of type of sugar. In conclusion, Taxol pre-treatment of oocytes before cryopreservation did not reduce the damage induced by vitrification and subsequently did not improve embryonic development following vitrification. Trehalose may be used as an alternative non-permeating cryoprotectant in vitrification solution.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.90-90
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• 2002

The purpose of this study was to investigate the effect of kind and combination of sugars on the viability and acrosome damage of post-thaw spermatozoa in canine. The extender used was Tris-citric acid extender (Tris-buffer) supplemented with 20% Egg-yolk, 8% glycerol, 1% Equex STM paste, and 70 mM sugars such as monosaccharide (fructose and xylose) and disaccharide(trehalose). To evaluate of sugar combination, the sugars supplemented in Tris-buffer were combined such as single (fructose, xylose, trehalose), two combinations (Fruc+Tre, Fruc+xyl, Tre+xyl) and three combinations (Fruc+Tre+Xyl). The concentration of sperm collected were adjusted of 50${\times}$10$\^$6/ per straw for freezing. The frozen spermatozoa were thawed at 37$^{\circ}C$ for 1 min and then analysis for CASA program in Livestock Improvement Main Center, NACF. The motility of post-thaw spermatozoa in Fruc+Tre was higher than those in fructose, trehalose, xylose, Fru+xyl, Tre+xyl and Fru+Tre+Xyl (79％ vs. 63, 66, 70, 71, 74 and 75%). The progressive motility after CASA analysis in Fuc+Tre group was also higher than those in fructose, trehalose, xylose, Fru+xyl, Tre+xyl and Fru+Tre+Xyl (67% vs. 53, 57, 60, 61, 62 and 64%). The acrosome damage of post-thaw spermatozoa stained was not significantly different among treatment groups such as fructose, trehalose, xylose, Fru+Tre, Fru+xyl, Tre+xyl and Freu+tre+xyl (17.7, 18.3, 28.0, 17.0, 19.7, 20.0 and 19.0%). The results indicated that the motility and progressive motility of post-thaw spermatozoa in Fru+Tre group was better, and acrosome normality was not different among all groups. The use of Tris-buffer supplemented with Fru+Tre as sugar for frezing of canine spermatosoa could be better and apply to semen banking and artificial insemination.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.143-149
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• 2003

This study was carried out to cryopreserve and to investigate characteristics of semen in Hanwoo. Semen was obtained from bulls selected by Daekwanryeong Branch station. Semen was collected each morning of the experiment, placed in water jacketed tubes at 37$^{\circ}C$, and trans-ported to the research laboratory within 10 minutes. Semen was extended with Egg yolk-glycerol extender to contain 50${\times}$10$^{6}$ sperm/ml. Semen was cooled over a 6h period in water jacketed tubes from about 25 to 5$^{\circ}C$, Egg yolk-glycerol extender was added in one step at 5$^{\circ}C$. Semen was aspirated into 0.5ml straws, which were sealed with powder. Egg yolk-glycerol extender, which is used in Hanwoo sperm frozen and stored, semen from 13 Hanwoo bulls collected, the postthawed percentages of motile sperm were 65.7%. In semen characteristics of Hanwoo bulls, number of bulls volume are 5.7 ml and total cell count are 975${\times}$10$^{6}$ m1 ejaculate.

• Journal of Embryo Transfer
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• v.9 no.1
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• pp.7-14
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• 1994

The present experiments on cryopreservation were designed to examine the effects of solution toxicity, equilibration time and cell stages on the post-thaw survival of bovine IVF embryos. The oocytes were matured in vitro(IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g /ml FSH, 10 $\mu$g /ml LH, 1 $\mu$g /ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro(IVC) with bovine oviductal epithelial cells for 7 to 9 days. The bovine IVF 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. 1. after the bovine blastocysts were exposed to EFS solution for 2 min. at room temperature and then they were washed in 0.5 M sucrose solution and TCM-199, they were cultured to examined cryoprotectant induced injury during exposure, Most of the embryos(95.0%) developed to reexpanded blastocoels. However, when the exposure time was extended to 5 and 10 min, these development rates dropped dramatically in 5 min. (69.5%) and 10 min. (47.4%), respectively, 2. When the bovine IVF embryos were vitrified in EFS solution after the equilibration for 1 and 2 min. exposure, The embryos to have reexpanded blastocoels following thawing, washing and culture processes were found to he 82.6 and 73.9%, respectively. However, when the exposure time was extended to 3 min, this survival rate dropped to 18.2%. The optimal time for equilibration of bovine IVF blastocysts in EFS solution seemed to he 1~2 min. 3. When the bovine IVF embryos were equilibrated for 1 min. the significantly (P<0. 05) higher post-thaw survival rates were obtained from the embryos of blastocyst stage(81.3%) than morulae stage(5. 1%). The optimal cell stage for viterification with EFS solution proven to he blastocyst stage in bovine IVF embryos. 4. The number of blastomeres of blastocyst stage was examined with nuclear staining with Hoechst 33342 during 7 to 9 days post-insemination. The cell counts of frozen bovine IVF embryos were found significantly(P$\geq$7.5 and those of the fresh embryos 76.6$\geq$7. 1, which were cultured in the sarne period and conditions as frozen embryos.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.51-59
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• 2003

This study was carried out to evaluate the effect of different freezing and thawing rates on the viability, motility and acrosomal changes of frozen canine spermatozoa. The ejaculated semen was extended with Tris-egg yolk buffer containing 8% glycerol and equilibrated for 60 min after cooled to 4$^{\circ}C$ for 58 min. The straws were cryopreserved gradually by slow-cooling at different distance(6, 10 and 17 cm, respectively) from the liquid nitrogen (L$N_2$) to achieve temperature rate of 3, 8.9 and 19$^{\circ}C$ /min. Thawing of the straws was performed in a water bath fur 2 min at 37$^{\circ}C$ and 55$^{\circ}C$ , respectively. The motility of frozen-thawed spermatozoa was assessed by phase-contrast microscopy. To assess their viability and acrosome content, spermatozoa were stained with a vital stain and Fluorescence conjugated lectin Pisum Savitum Agglutinin (FITC/PAS), respectively. Concentration of the ejaculated fresh semen was normal range of 3.44 $\times$ 10$^{8}$ /ml. Freezing temperature were reduced to -110, -70 and -35$^{\circ}C$, as higher distance from liquid nitrogen, 6, 10 and 17 cm, respectively. Freezing at 3$^{\circ}C$/min in distance of 17 cm from liquid nitrogen yielded better motility, viability and rate of intact acrosome than 8.9 or 19$^{\circ}C$/min and the optimal thawing was 37$^{\circ}C$ for 2 min.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.320-324
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• 2018

In this study, we examined effect of sperm penetration of oocytes after in vitro fertilization (IVF) with cauda epididymal spermatozoa in Hanwoo bull after feeding of timothy hay. One testicle with epididymides was castrated from one Hanwoo bull (14 months of age) and spermatozoa recovered from cauda epididymis and cryopreserved. As control, frozen Hanwoo semen was used. Matured cumulus oocyte complexes were co-incubated with frozen-thawed cauda epididymal spermatozoa for 12 or 18 hours. After IVF, presumptive zygotes were cultured in modified synthetic oviductal fluid. In experiment 1, we examined sperm penetration rate at 12 hours of IVF with epididymal sperm. Total penetration rate among cauda epididymis and control was similar(mean${\pm}$standard error, cauda epididymis and control vs. $49.7{\pm}11.3$ and $54.4{\pm}12.8%$). In experiment 2, cleavage and blastocyst developmental rate were evaluated at day 2 and day 8 after IVF for 18 hours. Cleavage rate among cauda epididymis and control was similar(cauda epididymis and control vs. $81.2{\pm}3.4$ and $82.7{\pm}2.5%$). However, blastocyst developmental rate of cauda epididymis group was significantly higher than that of control group(cauda epididymis and control vs. $24.4{\pm}1.6$ and $12.2{\pm}2.8%$, p<0.05). In conclusion, cauda epididymal spermatozoa in Hanwoo bull has high embryo developmental competence and can be used as an alternative to ejaculated frozen sperm in vitro.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.647-659
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• 1997

To overcome the difficulties of collecting and culture of primary cell from genital tract on embryonic development, the present study was carried out to investigate the critical effect of cell lines, such as BRL and Vero cell and its conditioned medium on the development of early Korean native cattle embryos in vitro. Oocytes collected from slaughterhouse ovaries were matured in TCM199 containing FSH, estradiol-$17{\beta}$ and FBS with granulosa cell monolayer for 24 hours and then fertilized in vitro using frozen-thawed, heparin-treated spermatozoa in TALP for 30 hours. And then early embryos (1-2cell) were cultured in TCM199 containing 10% FBS with BOEC, Granulosa, BRL, Vera cell monolayers and conditioned medium for 2~3 days. Development to morulae and blastocysts were recorded, also examined the number of blastomeres presented a valuable parameter for the evaluation of embryonic development. The early cleavage rates of in vitro fertilized embryos co-cultured, there was no differences between primary cell and cell lines(p<0.05). The rate of development to the later stage, coculture of BRL cell was significantly higher than that of the primary cell(p<0.05). The rates of development to morula and blastocyst were significantly higher in vero cell than BRL, Granulosa, Oviduct epithelial cell conditioned medium. In the result of effect of serum on development of early bovine embryos, the use of media containing serum were significantly higher than the use of not containing one on development of early and later stage of embryos. The result of number of blastomeres in blastocysts, there is no differences between primary cell and cell lines. The blastocysts from coculture were higher than from conditioned medium in blastomere cells. In summary, these experments have proved that the culture system in TCM199 with BRL, Vero cell monolayers is effective on in vitro development of early bovine embryos, In addition, it is effective to development of bovine embryos that containing serum in conditioned medium, or in co-culture rather than in conditioned medium alone. The use of cell lines opponent to primary cells is effective in bovine embryo culture.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.2
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• pp.117-124
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• 2007

Objective: The aim of this study was to compare the efficacy of slow freezing with vitrification method for cryopreservation of mouse pronuclear stage embryos. Methods: Mouse pronuclear embryos obtained from superovulated mice and classified into 2 groups of slow freezing and vitrification. Slow freezing solution consisted of 1.5 M PROH, 0.1 M sucrose, while vitrification solution consisted of 40% ethylene glycol, 18% Ficoll and 0.5 M sucrose diluted in Dulbecco's phosphate-buffered saline supplemented with 10% SSS. Recovery and survival rates after thawing and development rates to hatching balstocyst stage were compared between two groups. Results: After freezing and thawing, recovery rate of slow freezing group was 93.8%, whereas vitrification group was 66.5% (p<0.01). Survival rate of recovered embryos were similar between two groups as 83.2% in slow freezing and 87.6% in vitrification. Embryo development rates to 2-cell stage after 24 hrs (77.0% vs 59.1%), 4-cell after 48 hrs (72.6% vs 53.3%), blastocyst after 96 hrs (53.1% vs 40.1%) of thawing were significantly higher in vitrification group than those of slow freezing group, respectively. Conclusion: The vitrification method may provide better developmental competence of frozen-thawed embryos than that of slow freezing method for cryopreservation of mouse pronuclear stage embryos.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.919-927
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• 1996

In the last few years, methods for in vitro culture of early embryo stages from oocytes matured and fertilized in vitro using suitable cell culture systems have been established. But the factors affecting pregnancy rates following transfer of bovine embryos produced in vitro were not evaluated enough. So this study was performed to investigate the effects of quality and stage of embryos, parity and Corpus Luteum quality of recipients on pregnancy rates following non-surgical transfer of bovine embryos produced in vitro. Oocytes aspirated from small antral follicles of ovaries obtained at a local slaughter house were matured, fertilized with frozen-thawed semen and co-cultured for 6-7 days by utilizing co-culture system with bovine oviduct epithelial cell in vitro. After co-culture, embryos were transfered to recipients on day 7 (estrus=day 0). Recipients were monitored by ultrasonic scanning method or observation for estrus and rectal palpation after 50 days from transfer. The results of this study are follows. 1. Of the 70 recipients, 70%(49 of 70) had not showed estrus sign between day 0 and day 50, but 22.9%(16 of 70) was diagnosed not pregnant. Therefore the overall pregnancy rate of this study was 47.1%(33 of 70). 2. The pregnancy rate of recipients transfered with excellent(66.7%) and good(54.5%) embryos were higher than that of recipients transfered with fair embryos(15.8%) (p<0.05). 3. The pregnancy rate of recipients transfered with morula, compacted morula, blastocyst and expanded blastocysts were 46.2, 55.0, 62.5 and 50.0%, respectively. 4. The pregnancy rates of recipients transfered to heifer and cow were 54.5 and 55.2%, respectively. 5. The pregnancy rates of recipients with CL score I, II(66.7, 63.6%) were higher than those of recipients with CL score III (10%), (p<0.05). Success of transfer of embryos produced in vitro depends on many variables. The important factors identified in this study were the quality of embryos and the CL score of recipient animals after non-surgical transfer of embryos matured, fertilized and cultured in vitro.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.1-7
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• 2007

This study was conducted to examine the role of intact cumulus cells during in vitro fertilization (IVF) on sperm penetration, male pronuclear (MPN) formation and subsequent embryo development of oocytes matured and fertilized in vitro. Cumulus-oocyte complexes obtained from the slaughtered gilt ovaries were matured for 44 h in TCM199 containing 10% porcine follicular fluid, epidermal growth factor and hormones. After maturation culture, denuded oocytes or oocytes with intact cumulus cells were coincubated with frozen-thawed boar semen for 8h in a modified tris-buffered medium containing 5mM caffeine and 10mM calcium chloride. Putative zygotes were fixed and examined for sperm penetration and MPN formation (Experiments $1{\sim}3$), or cultured in North Carolina State University-23 medium fo. 156 h (Experiment 3). In Experiment 1, sperm penetration was examined after insemination of denuded oocytes and oocytes with intact cumulus cells at the concentration of $7.5{\times}10^5$ sperm/ml. Optimal sperm concentration for IVF of cumulus-intact oocytes was determined in Experiment 2 by inseminating intact oocytes with $2{\sim}5{\times}10^6$ sperm/ml. In Experiment 3, denuded or intact oocytes were inseminated at the concentrations of $7.5{\times}10^5$ and $4.0{\times}10^6$ sperm/ml, respectively, and in vitro embryo development was compared. Sperm penetration was significantly (p<0.01) decreased in cumulus-intact oocytes compared to denuded oocytes (35.2% vs. 77.4%). Based on the rates of sperm penetration and normal fertilization, the concentration of $4.0{\times}10^6$ sperm/ml was optimal for the IVF of intact oocytes compared to other sperm concentrations. The presence of intact cumulus cells during IVF significantly (p<0.05) improved embryo cleavage (48.8% vs. 58.9%), blastocyst (BL) formation (11.0% vs. 22.8%) and embryo cell number $(22{\pm}2\;vs.\;29{\pm}2\;cells)$ compared to denuded oocytes. In conclusion, these results suggest that intact cumulus cells during IVF inhibit sperm penetration but improve embryo cleavage, BL formation and embryo cell number of porcine embryos produced in vitro.