• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.22-27
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• 1999

Bovine oocytes with compact and complete cumulus cells were cultured in 6 groups for up to 24h in TCM199 buffered with 25 mmol/1 HEPES and supplemented with 10% FCS, 1 mg/ml $17{\beta}$-estradiol, 20 IU/ml hCG. Half of the oocytes at each group cultured in the presence of $25{\mu}g/ml$ cycloheximide at different times during maturation (0, 6, 12, 18, 20, 22 h) were fixed at 24 h of maturation to examine the nuclear progression. The rests of them were inseminated with frozen-thawed spermatozoa in medium BO with 10 mg/ml BSA and 10 mg/ml heparin and fixed after additional 18-20 h culture to evaluate the sperm head transformation. When a protein synthesis inhibitor was added at the onset of the maturation, the oocytes were prevented to proceed GVBD. A few of the oocytes (16%) were able to be penetrated and sperm head decondensation was inhibited either. Addition of cycloheximide after 6-12 h of culture resulted in an increasing percentage of GVBCD (more than 80%), but the oocytes became arrested in M-I (69.2%). More than half of the oocytes was penetrated with a decondensing sperm head. Formation of male pronucleus was first obtained at 12 h of culture in the presence of cycloheximide. When cycloheximide was added from 18 h of culture onwards, nuclear progression to M-II was increasingly restored (80.4-85.5%). The proportion of male and female pronuclear formation increased from 17.9% to 46.2%. It is concluded that protein synthesis is necessary not only for GVBD and development from M-I to M-II, but also for sperm head decendensation and male pronuclear formation in bovine oocytes.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.55-62
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• 1992

Bovine oocytes obtained from ovarian(2 to 5mm in diameter) of slaughtered cows were cultured in TCM 199 with 10~20% estrous-cow-serum(ECS) for 24~25hr at 39$^{\circ}C$ in 5% CO2-95% air. After culture, some oocytes were examined their maturation. The remainder were used to assess the fertilizability with frozen-thawed spermatozoa in a medium containing caffeine and heparin, and subsequent development in media with bovien cumulus cells(BCC) or bovine oviduct epithelial cells(BOEC). The results obtained were summarized as follows ; 1. The maturation rate of the oocytes in TCM199 with 15% ECS group(76.5%) was higher than that of 10% ECS(69.2%) or 20% ECS group(64.8%). 2. The proportions of the oocytes penetrated and the pronuclear oocytes in the presence of caffeine and heparin were 72.1%(62/86) and 93.5%(58/62), respectively. The rate of polyspermy in the fertilized oocytes was 8.1%. 3. When 73 oocytes recovered from fertilization drop were cultured in TC-199 medium with 10% fetal calf serum(FCS), 41 oocytes(56%) cleaved to 2-cell and further stages of embryos. Among these only one embryo developed upto morula stage. 4. The rate of the cleaved oocytes was higher in medium with BCC(80%:59/74) than BOEC(76%:58/76). However, the rate of developed morulae and blastocysts was higher in the medium with BOEC(40%;23/58) than with BCC(34;20/59).

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.111-116
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• 1997

We determined the effects of follicular fluid fractions in the maturation medium on bovine oocyte maturation, fertilization and subsequent development, as well as on number of cells in blastocysts following culture. Follicular fluid and oocytes from bovine follicles less than 5 mm in diameter were collected from the ovaries of slaughtered cows. Follicular fluid was separated into different molecular weight fractions by untrafiltration through a membrane using a centrifuge at 500$\times$g, for 2h. For the maturation medium, follicular fluid fractions (30%, v/v), whole fluid (30%) or PVP(3mg/ml) were added to TCM 199(0.1$\mu\textrm{g}$/ml estradiol-17$\beta$, 100IU hCG). After maturation for 24h, oocytes were fertilized in vitro with bull frozen-thawed spermatozoa and cultured on a monolayer of granulosa cells for 9 days after fertilization. There were no differences in maturation rates or fertilization rates among any maturation conditions. The rates of development to >2-cell stage of the oocytes were significantly decreased when fraction of follicular fluid below 10,000 MW were added into maturation medium, compared with control and fraction above 10,000 MW(26.0% vs 40.8% to 64.0%, respectveily. p<0.01). Likewise, the rates of development to blastocysts of fertilized oocytes were significantly decreased in maturation medium containing fraction of follicular fluid (<10,000 MW). The average cell number of blastocysts derived from oocytes that matured in the fraction(>10,000 MW) of follicular fluid was 154.7$\pm$13.7. These embryos contained more cells than those matured in whole follicular fluid, or the fraction(<10, 000 MW) of follicular fluid or control(107.0$\pm$8.4, 91.8$\pm$11.8 and 95.8$\pm$6.2, respectively). In conclusion, we found that fractions of follicular fluid contained factors stimulating or inhibiting oocyte cytoplasmic matruation. These suggest that a factor(s) inducing cytoplasmic maturation of oocytes may exist in >10,000 MW fraction of follicular fluid.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.85-91
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• 2011

The objective of this study was to evaluated the efficiency on sperm cryosurvival and ability of in vitro fertilization using Triladyl and Lactose Egg-Yolk(LEY) as extenders for cryopreservation of separated sperm by 65% percoll in miniature pig. Sperm viability was measured with SYBR-14/PI double stained sperm by flow cytometry. Ability on embryo cleavage rate and blastocyst development were observed by in vitro fertilization after frozen-thawing of sperm separated by 65% percoll. The experimental groups were designed that separated sperm by 65% percoll with Triladyl (ST) or LEY(SL) and unseparated sperm with Triladyl(UT) or LEY(UL) for cryopreservation. As a results, the viability was significantly(p<0.05) higher in ST(55.1%), SL(63.1%), UL(58.8%) than UT(38.2%) group. Sperm viability in SL(63.1%) group was significantly(p<0.05) higher than other experimental groups. On the other hand, embryo cleavage rate was significantly(p<0.05) higher in ST(79.1%), SL(83.2) than UT(74.1) and UL(75.7%) groups at 96h after in vitro fertilization. Blastocyst development was also significantly(p<0.05) higher in ST(21.5%), SL(20.9%) than UT(17.0%) and UL(18.8%) groups. In conclusion, cryopreservation of miniature boar sperm separated by 65% percoll were beneficial to viability and capacity on in vitro fertilization.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.295-300
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• 2011

The objective of this study was to evaluate efficiency of methyl-beta-cyclodextrin (MBCD) in the sperm preservation of bull. For this study, the freezing of diluted semen were added with Triladyl containing 20% egg-yolk and/or 0, 1, 5, 10 and 20 mM MBCD before freezing process. Analysis of viability in frozen-thawed sperm was estimated by SYBR14/PI double stain, hypoosmotic swelling test(HOST) and acrosome damage with FITC-PNA, and mitochondria activation with Rhodamin123 by flow-cytometry. The sperm viability was significantly in 0 mM and 5 mM concentrations of MBCD than other groups (p<0.05). However, the HOST was significantly lower at 20 mM concentration of MBCD than other concentrations (p<0.05). In addition, acrosome damage and mitochondria activation rates were significantly lower at 20 mM concentration of MBCD than other groups (p<0.05). In conclusion, the viability of sperm was not significantly different among concentrations of MBCD 0, 5 and 10 mM, but MBCD 20 mM was significantly lower than other groups. In addition, as concentrations of MBCD was high, HOST, acrosome damage and mitochondria activation rates had a negative effect in bull sperm.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.6
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• pp.754-758
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• 2001

Bovine oocytes with compact and complete cumulus cells were cultured for up to 24h in TCM199 buffered with 25mmol/l hepes and supplemented with 10% FBS (fetal bovine serum), 1mg/ml $17{\beta}$-estradiol, 20IU/ml hCG(human chorionic gonadotropin). All of the oocytes were divided into at 6 groups depending upon incubation times (control, 0 hour, 6 hours, 12 hours, 16 hours, 18 hours). To all experimental media, $200{\mu}g/ml$ puromycin was added at different incubation times mentioned above. Following these culture times, in vitro insemination was conducted with frozen-thawed bovine spermatozoa in medium BO (Brackett and Oliphant medium for in vitro insemination) with $10{\mu}g/ml$ BSA(bovine serum albumin) and 10 mg/ml heparin added. After 22h culture, the oocytes were fixed with acetic alcohol solution and stained with orcein acetic solution to evaluate sperm nuclear progression. Addition of puromycin after 0, 6 and 12 h of culture resulted in near of oocyte maturation at the M1 stage. Contrariwise, puromycin addition after 12 h of culture led to restoration of nuclear progression to M2 stage. On the one hand, puromycin affected the synthesis of Cyclin B protein that may be involved in the oocyte maturation and sperm capacitation for in vitro fertilization. The present study suggests the participation of protein synthesis, cyclin B, in the oocyte development from M1 to M2 stages in vitro.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.4
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• pp.175-180
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• 2015

Objective: Embryo loading (EL) is a major step in embryo transfer (ET) and affect on the success of in vitro fertilization (IVF). This study aimed to compare the effect of two different EL techniques on the rates of pregnancy and delivery in IVF/ET cycles. Methods: 207 fresh ET and 194 Frozen-thawed ET (FET) cycles were included in this retrospective study. Two groups (A and B) were defined based on the EL technique used. In group A, the entire catheter was flushed with Ham's F-10 medium. The embryos were then drawn into the catheter using one air bracket. In group B, $70{\mu}L$ of air was aspirated into the syringe and the catheter was flushed using Ham's F10 medium. The medium, air, embryos, air, and finally another layer of medium were then sequentially drawn into the catheter. The main outcome measures were the pregnancy and delivery rates. Results: The groups did not differ with respect to the etiology of infertility, the source of spermatozoa, the quality of the embryos, the type of EL catheter, and the ease of transfer. The pregnancy rate was similar between two groups. In fresh ET cycles, a higher delivery rate was observed in group B than it group A (78.1% vs. 60%, p=0.1). In FET cycles, the rate of delivery was significantly higher in group B than in group A to a nonsignificant extent (88.9% vs. 58.8%, p=0.06). Conclusion: EL techniques did not have a significant impact on the delivery rate in either fresh or FET cycles.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1411-1420
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• 2020

Objective: The aim of study was to investigate the effects of season and single layer centrifugation (SLC) before cryopreservation on post-thaw bull sperm quality in Thailand. Methods: Semen was collected from 6 bulls (Bos indicus) in summer, rainy season and winter 2014 through 2016. Semen characteristics, sperm morphology, sperm kinematics, viability, chromatin structure and mitochondrial membrane were evaluated. Meteorological data were available from the local meteorological station; Results: Season had an effect on semen characteristics in the raw ejaculate, with higher proportions of normal spermatozoa and lower abnormalities in winter than in the other two seasons. Sperm kinematics, viability, DNA fragmentation index, and mitochondrial membrane potential were not different between seasons. Sperm samples selected by SLC had greater normal morphology and a lower proportion with bent tails than controls and higher values of progressive motility (PRO), beat cross frequency, linearity, straightness, wobble (WOB), and lower values of slow motility, velocity average path (VAP), velocity curved line, and amplitude of lateral head displacement than controls. In addition, SLC-selection had a favorable effect on PRO, VAP, and WOB that differed among seasons. Conclusion: Our results suggested that these bulls were well adapted to their location, with season having an effect on sperm morphology. Moreover, SLC could be used prior to cryopreservation, regardless of season, to enhance normal morphology and kinematics of bull sperm samples without adversely affecting other parameters of sperm quality. However, there was considerable variation among bulls in DNA fragmentation index, mitochondrial membrane potential and sperm viability. In addition, SLC had a positive effect on sperm morphology and sperm kinematics, which could be expected to influence fertility.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.235-239
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• 2005

This study was conducted to test whether the transgenic cattle pass the transgene to their progeny through germ cells, and whether the transgene is expressed in the mammary gland of ransgenic cows. Two male ransgenic calves were born from IVF-derived embryos injected with bovine $\beta-casein/human$ lactoferrin fusion gene and then grew up to be reproducible. Semen was collected from a transgenic bull after 18 mon of age and then frozen. Bovine oocytes matured in vitro were fertilized with spermatozoa of the transgenic bull and cultured in $50\;{\mu}L$ drops of CRlaa medium supplemented with 3 mg/mL BSA. After 48 h of culture, cleaved embryos were determined for the presence of transgenes by DNA polymerase chain reaction (PCR). Proportion of transgene positives among bovine embryos fertilized with sperm of the transgenic bull was $20.9\%$ (28/134). One of transgenic bulls did not produce transgenic sperm. Out of 34 calves produced from recipient heifers inseminated with semen of the other bull, 3 $(8.8\%)$ were transgenic animals (2 females and 1 male). Thus, one transgenic bull showed a low transmission frequency below Mendelian levels in both the IVF-derived embryos and his progeny. It was demonstrated by Southern blot that copy numbers of the transgene in the transgenic progeny enhanced about 1.8 times as compared to those of the founder bull The results demonstrate that the transgenic bull carrying human lactoferrin gene could pass his transgene to the progeny through germ cells, although he is a germ-line mosaic.