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

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.9
• /
• pp.1420-1430
• /
• 2018

Objective: Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols and is considered one of the most promising bioactive compounds in green tea because of its strong antioxidant properties. However, the protective role of EGCG in bovine oocyte in vitro maturation (IVM) has not been investigated. Therefore, we aimed to study the effects of EGCG on IVM of bovine oocytes. Methods: Bovine oocytes were treated with different concentrations of EGCG (0, 25, 50, 100, and $200{\mu}M$), and the nuclear and cytoplasmic maturation, cumulus cell expansion, intracellular reactive oxygen species (ROS) levels, total antioxidant capacity, the early apoptosis and the developmental competence of in vitro fertilized embryos were measured. The mRNA abundances of antioxidant genes (nuclear factor erythriod-2 related factor 2 [NRF2], superoxide dismutase 1 [SOD1], catalase [CAT], and glutathione peroxidase 4 [GPX4]) in matured bovine oocytes were also quantified. Results: Nuclear maturation which is characterized by first polar body extrusion, and cytoplasmic maturation characterized by peripheral and cortical distribution of cortical granules and homogeneous mitochondrial distribution were significantly improved in the $50{\mu}M$ EGCG-treated group compared with the control group. Adding $50{\mu}M$ EGCG to the maturation medium significantly increased the cumulus cell expansion index and upregulated the mRNA levels of cumulus cell expansion-related genes (hyaluronan synthase 2, tumor necrosis factor alpha induced protein 6, pentraxin 3, and prostaglandin 2). Both the intracellular ROS level and the early apoptotic rate of matured oocytes were significantly decreased in the $50{\mu}M$ EGCG group, and the total antioxidant ability was markedly enhanced. Additionally, both the cleavage and blastocyst rates were significantly higher in the $50{\mu}M$ EGCG-treated oocytes after in vitro fertilization than in the control oocytes. The mRNA abundance of NRF2, SOD1, CAT, and GPX4 were significantly increased in the $50{\mu}M$ EGCG-treated oocytes. Conclusion: In conclusion, $50{\mu}M$ EGCG can improve the bovine oocyte maturation, and the protective role of EGCG may be correlated with its antioxidative property.

• Reproductive and Developmental Biology
• /
• v.38 no.4
• /
• pp.143-146
• /
• 2014

Antioxidants, as reactive oxygen species scavengers, are one of the beneficial additives in serum-free defined culture medium. In this study, three separate experiments were performed to determine the effects of 3-hyroxyflavone added to the culture medium on the developmental competence of follicular bovine oocytes during in vitro maturation (IVM) and/or in vitro culture (IVC). The rate of blastocyst developed from oocytes cultured in IVM medium with 3-hyroxyflavone was significantly higher than that from control oocytes (39.0% vs. 26.3%, p<0.001), respectively. However, oocytes cultured in the medium with addition of 3-hyroxyflavone only at IVC period did not show significance in the blastocyst development when compared with control. When 3-hyroxyflavone was added to both IVM and IVC media, the rate of blastocyst formation was even significantly lower (21.1%) than control (26.5%; p<0.05). The present findings suggested that antioxidative activity of 3-hydroxyflavone added to only IVM medium beneficially affected the developmental competence of follicular bovine.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.3
• /
• pp.307-310
• /
• 1998

The present studies were undertaken to evaluate the effects of a low concentration of dimethyl-sulfoxide (DMSO) on in vitro maturation and development of bovine oocytes fertilized in vitro. Significantly more oocytes reached the metaphase stage of the second meiotic division in TCM-199 supplemented with $50{\mu}M$ DMSO than in the control medium (p < 0.05), and the highest rates of development up to the blastocyst stage were obtained when $50{\mu}M$ DMSO was added to the maturation and culture media (p < 0.05). The avarage of cell numbers of the blastocysts, expanded and hatched blastocysts cultured with $50{\mu}M$ DMSO were 81.7, 125.7 and 129.9 cells, respectively. The proportion of blastocysts with normal chromosome numbers was 90.5%. These results suggest that the addition of $50{\mu}M$ DMSO is beneficial for the maturation of bovine oocytes and production of the blastocysts with high quality.

• Journal of Embryo Transfer
• /
• v.15 no.1
• /
• pp.39-46
• /
• 2000

This study was conducted to investigate the effect of hormones, protein sources and anti-oxidants on in vitro maturation (IVM) and in vitro fertilization(IVF) of bovine follicular oocytes. The rates of Holstein follicular oocytes classified as grade A and B(50.2% and 33.2%) were higher than those of Hanwoo cattle(40.3% and 32.0%, P<0.05). The cumulus cell expansion rates of oocytes cultured in TCM-199 and Ham's F-10 medium supplemented with 10% FCS and hormones were higher (81.9~87.6%) than those of non-treated groups (74.5~81.7%). The fertilization rates of oocytes cultured in TCM-199 and Ham's F-10 medim supplemented with 10% FCS, 1% BSA and 10% bFF was 53.8~55.0%, 51.4~52.6%, and 47.0~50.0%, respectively. The polyspermy rates was 13.6~14.2%, 10.0~11.1%, and 10.0%, respectively. When the oocytes were cultured in TCM-199 and Ham's F-10 medium with 50${\mu}{\textrm}{m}$ $\alpha$-tocopherol, the fertilization rates was 62.0 and 60.2%, respectively. In the maturation medium added of 100${\mu}{\textrm}{m}$ cysteamine, the fertilization rates was 64.7 and 66.7%, respectively. The fertilization and polyspermy rates of treated groups were higher than those of non-treated group. The results show that hormones, protein sources and anti-oxidants can provide a benefit for in vitro maturation and fertilization of bovine follicular oocytes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.1
• /
• pp.22-27
• /
• 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
• /
• v.22 no.2
• /
• pp.195-202
• /
• 1998

We demonstrated, for the first time, pronuclear formation and apposition in porcine ooc-ytes following intracytoplasmic injection of porcine, human, bovine and mouse spermatozoon. Microtubule organization and chromatin configuration were investigated in these oocytes during pronuclear apposition. Following intracytoplasmic injection of porcine spermatozoon, the microtubular aster was organized from the neck of spermatozoon, and filled the whole cytoplasm. This male derived microtubules appear to move both pronuclei to the center of oocytes. In contrast, following injection of spermatozoa from different species such as human, bovine and mouse, microtubules were organized from the cortex of the oocytes and concentrated to the pronuclei, which seems to move both male and female pronuclei to the center of oocyte. This organization is similar to what has been shown in the parthenogenetically activated por-cine oocytes. These results suggested that the porcine, human, bovine and mouse sperm chromatin can be formed pronucleus and apposited in the center of oocytes in the absence of male derived microtubule when they were injected into porcine oocytes.

• Korean Journal of Animal Reproduction
• /
• v.20 no.3
• /
• pp.353-360
• /
• 1996

The study was conducted to determine the optimal cumulus cells, glucose and superoxide dimutase(SOD) levels during the in vitro culture of bovine oocytes matured and fertilized in vitro for morulae and blastocyst development. Oocytes were cultured for 0~8 days in TCM-199 medium supplemented with 20% FCS, cumulus cells and with different glucose and SOD levels. The results are summarized as follows; 1. The in vitro developmental rates of bovine oocytes cultured in TCM-199 medium containing cumulus cells and 0.1, 0.5, 1.0, 5.0mM glucose levels 0~3 and 0~8 days after insemination were 21.1, 25.0, 23.3, 17.9 and 26.3, 25.7, 23.1, 19.4% respectively and there was significant differences on the development to the molurae and blastocysts stage among the cumulus cells and glucose levels. 2. The in vitro developmental rates of bovine oocytes cultured in TCM-199 medium containing 0.1, 0.5, 1.0, 5.0mM glucose levels 0~3 and 0~8 days after insemination were 11.3~24.5% and 17.3~25.0%, respectively. 3. The in vitro developmental rates bovine oocytes cultured in TCM-199 medium containing 100, 200, 300, 500 $\mu\textrm{g}$/ml SOD levels 0~3 and 0~8 days after insemination were 12.5~22.9% and 12.9~22.2%, respectively. Hight levels of SOD(500$\mu\textrm{g}$/ml) significantly reduced the rates ofmolurae and blastocysts stage(P<0.05).

• Journal of Embryo Transfer
• /
• v.24 no.2
• /
• pp.121-125
• /
• 2009

In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrifiedthawed bovine oocytes were examined. Also, the developmental capacity of vitrified-thawed immature oocytes following ICSI was investigated. Oocytes were cultured in TCM-199 medium supplemented with 5% FBS at $38^{\circ}$C in 5% $CO_2$ and air. The in vitro maturation rate of vitrified oocytes was 24.5 ${\pm}$ 4.2%. The in vitro maturation rate of vitrified oocytes was lower than that of the control (72.0 ${\pm}$ 3.5%, p<0.05). The in vitro maturation rate of vitrified${\sim}$thawed oocytes incubated in TCM-199 medium supplemented with 1.0${\sim}$5.0 ug CB were 26.7 ${\pm}$ 3.2%, 35.7 ${\pm}$ 3.2%, 54.0 ${\pm}$ 3.0%, 42.5 ${\pm}$ 3.6%, respectively. The in vitro maturation rate (57.0 ${\pm}$ 3.0%) of the vitrified-thawed oocytes treated with 3.0 ${\mu}$g CB for 20 min was the highest of all vitrification groups, although the maturation rate were significantly (p<0.05) lower than those of fresh oocytes. The in vitro maturation rates of the vitrified-thawed (with EDS and EDT) oocytes were 53.8 ${\pm}$ 3.4%, 51.1 ${\pm}$ 3.5%, respectively. This results were lower than the control group (72.0 ${\pm}$ 3.0%). The in vitro developmental rates of the vitrified-thawed oocytes following ICSI were 28.6 ${\pm}$ 4.5%, 25.6 ${\pm}$ 4.3%, respectively. This results were lower than the control group (40.0 ${\pm}$ 4.0%).

• Korean Journal of Animal Reproduction
• /
• v.14 no.1
• /
• pp.17-22
• /
• 1990

The present study was carried to investigate the development potential of bovine follicular oocytes matured and fertilized in vitro. Bovine oocytes matured in vitro were fertilized, cultured, and transfered to the rabbit oviduct for in vitro culture to evaluate the development potential. The rates of in vitro maturation, fertilization and polyspermy were 96%(355/369), 90%(320/355) and 15%(17/320), respectively. The percentage of oocytes cleaved after culture for 48 hours, to 2 cell, 3~4 cell, 6~8 cell stage were 17%(60/356), 21%(75/356) and 19%(67/356), respectively and overall cleavage rate was 57%(202/356). The rate of recovered embryos after 5 days in rabbit oviduct was 56%(80/142), and 21%(17/80) of recovered embryos developed over morula stage.