• Reproductive and Developmental Biology
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• v.38 no.2
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• pp.63-70
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• 2014

Plasminogen activators (PAs) are serine proteases that convert plasminogen to plasmin. Two type of PAs are urokinase-type PA (uPA) and tissue-type PA (tPA). Plasminogen is present in most extracellular fluids. PAs play in various reproductive processes including implantation, ovulation and fertilization. In the spermatozoa, PAs and PAIs play a role in sperm motility and fertilization. PAs in the sertoli cell are stimulated spermatozoa maturation and sperm activation through the phospholipase A2. The oocyte maturation is the process for fertilization and implantation. PAs in cumulus-oocyte complexes (COCs) are related to oocyte maturation by protein kinase A and C. In the ovulatory process, PAs activity are changed and it are related to reducing the tensile strength of ovarian follicle wall. The uterine environment is important for reproduction and the uterus undergo tissue remodeling. In the uterus and oviduct of mammals, expression and activity of PAs are changed during estrous cycle. Thus, expression and activity of PAs are concerned to many reproductive functions. Therefore, PAs seem to important factor of regulator in reproductive events.

• Reproductive and Developmental Biology
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• v.31 no.2
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• pp.109-113
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• 2007

This study was conducted to evaluate the effect of cytochalasin B (CB) treatment in the activation medium on the development of somatic cell nuclear transfer (SCNT) rat embryos. Fetal fibroblast cells were isolated from a Day 14.5 fetus, and the oocytes for recipient cytoplasm were recovered from 4-week old Sprague Dawley rats. After enucleation and nuclear injection, the reconstructed oocytes were immediately exposed to activation medium consisting of 10 mM $SrCl_2$ with or without CB for 4 hr, and formation of pseudo-pronucleus (PPN) was checked at 18 hr after activation. Then, they were transferred into day 1 pseudopregnant recipients (Hooded Wistar) or cultured for 5 days to check their developmental competence in vivo or in vitro. The number of PPN was not affected by CB treatment during the activation. However, CB treatment supported pre-implantation development of rat SCNT embryos. Embryos generated by the procedures of SCNT were also capable of implanting, with 1 implantation scar found from a recipient following the transfer of 87 SCNT embryos to four foster mothers. The result of the present study shows that rat SCNT embryo can develop to post-implantation stage following treatment with CB.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.165-169
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• 2010

This study was carried out to assess the effect of vitamin E against the reactive oxygen species (ROS) on chemical activation of in vitro matured oocytes. Bovine oocytes were aspirated from slaughtered ovaries and transferred to maturation medium with or without vitamin E ($100\;{\mu}M$). After 22 hours of culture, oocytes with polar bodies were selected and submitted to activation treatments with or without vitamin E. After activation, oocytes were cultured in mSOF medium and rate of development was monitored. For ROS ($H_2O_2$) detection, in vitro matured and activated oocytes were selected and stained with DCFDA and observed under fluorescence microscope. The ROS contents were not significant differences in IVM rate, activation process and embryonic development to blastocysts with or without vitamin E. The cell number of blastocyst showed significant difference (p<0.05) in embryos matured and activated with vitamin E. The results of the present study demonstrated that the exposure of vitamin E in IVM and activation process improved the quality of embryos evaluated by the cell number of blastocysts.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.1-5
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• 2001

A total of 92 unfertilized human oocytes were treated with ethanol (EtOH), calcium ionophore A23187 (CI) or electric pulse (EP) for activating pronuclear formation and subsequent development. In Experiment 1, there was a significant (P=0.0001) treatment effect on the activation of unfertilized oocytes. No spontaneous activation was occurred in the control, but activation treatments induced PN formation with various efficacy. More unfertilized oocytes (UFOs) were activated after EtOH or EP treatment than after CI treatment. EP was as effective (63.6 %) as EtOH, but fragmentation was observed in 43% of UFOs activated by EP. Proportion of UFOs that formed presumptive haploid PN (2 PNs+1 PB or 1 PN +2 PBs) was 33.3, 0 and 28.6% after EtOH, CI and EP treatments, respectively. In Experiment 2, a significant (P=0.0362) effect of immature oocytes (IOs) status on activation was fecund. IOs at the GVBD-MI oocytes had higher potential to form PN than those at the GV stage or with abnormal morphology (25 vs. 77.8%). The results of this study clearly demonstrated that the treatment of 10% ethanol for 5 min effectively induced the activation of UFOs. IOs could form pronucleus with high efficacy by ethanol treatment, as long as they grew beyond the GVBD stage.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2006.10a
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• pp.100-101
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• 2006

• Reproductive and Developmental Biology
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• v.30 no.2
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• pp.115-118
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• 2006

Cyclin B1 is known to reflect the M-phase promoting factor (MPF), a universal regulator of G2/M-phase transition, activity during the process of oocytes maturation. To investigate whether culture condition affects the maturation rate and the expression of cyclin B1 protein, bovine immature oocytes are stimulated and cultured according to the following protocols: Experiment 1: denuded oocytes (denude) only, COC only, denuded oocytes+granulosa cells (denude+GCs) and COC+GCs; Experiment 2: no-activation (control), 7% ethanol for 5 min and $10{\mu}l/ml$ ionomycin for 5 min at immediately before maturation. The maturation rates of denude and no-activation group were significantly lower in both experiments (P<0.05), respectively. Co-culture or stimulation method in bovine immature oocytes culture increases the cyclin B1 expression significantly in both experiments (P<0.05). Based on these results, culture condition affects the maturation rate and the expression of cyclin B1 protein during the first meiotic maturation in bovine immature oocytes.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.113-119
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• 1994

To improve nuclear transplantation(NT) efficiency and to produce a large scale genetically identical cloned calves, examined the in vitro development capacity after co-culture of bovine oviductal epithelial cells (BOEC) and granulosa cells in TCM-199 supplemented with 10% fetal calf serum (FCS) with early bovine embryos derived from in vitro matured fertilized(IVM-IVF) oocyte. In addition, the age dependence of IVM oocyte on electro-stimulation and the effective electric voltage on in ivtro development of bovine NT embryos were examined. The results obtained were summerized as follows; 1. The cleavage rates of IVM-IVF bovine embryos in co-culture with bovine oviductal epithelial cells and granulosa cells were not significantly different(P<0.05), but the developmental rate into morula and blastocyst stage were different showing 38.3 and 20.2%, respectively. 2. The activation (82.5%) and development in vitro(8.6%) into later embryo stages of the aging oocytes of 32 hours post-maturation (hpm) were significantly higher than those of 24 hpm at direct current (DC) voltage of 1.5kV/cm, 60$\mu$sec pulse duration and 1 pulse time. 3. The fusion rates of NT eggs of 32 hpm following to different DC voltages from range 0.75 to 1.5kV/cm were not differ, but the developmental rate into morula and blastocyst stages at DC voltages of 0.75 and 1.0kV/cm were higher(11.4 and 12.6%, respectively) than those of 1.5kV/cm(0%). From these results, it can be suggested the optimal culture system for in vitro culture of IVM-IVF bovine embryos is a co-culture system with BOEC in TCM-199 supplemented 10% FCS. The effective time and the DC voltage for activation, electrofusion and in vitro development of NT embryos derived from IVM-IVF bovine embryo are 32hpm and 0.75~1.0kV/cm. But to improve NT efficiency, the advanced research (cell cycle synchronization, micromanipulation, culture system, etc.) is needed.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.109-109
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• 2003

Even though success in birth of live offspring from nuclear transfer(NT) using somatic cells in many species, detailed information on processes or mechanisms of development are not well known. Cytoplasm of bovine oocyte has been known to support the development of nuclear transferred embryos using nuclear donor cells from different species. Therefore, interspecies NT might be used to find answers of some questions in basic aspect of nuclear transfer In this study, we examined the developmental potential of reconstructed embryos when bovine oocyte as a cytoplasm recipient and mouse embryonic fibroblast as a nuclear donor were used. The nuclear transfer units were aliocated in Group 1 (murine block media and normal media) and Group 2. (bovine block media and normal media). NT units were not blocked at 2-cell stage regardless of types of medium. On mouse media, poor development of interspecies NT units was observed compared to bovine media. However, as NT units cultured in bovine normal medium, embryos developed over 8-cell stage. Further studies performed to increase the developmental rate in condition of antioxidant treatment. Despite low development, bovine-murine interspecies nuclear transferred embryos could develop to blastocysts and they showed that blastocyts rate of antioxidant group was superior to those of non-antioxidant group. Next, we investigated gene expression pattern which is carried out for zygotic activation. The Xist gene is expressed in female mouse embryo after zygotic activation of 4-cell stage. But interspecies nuclear transferred embryos do not express Xist gene at 4-cell stage. As a result, it is suggested that the bovine cytoplasm controls the early preimplantation development in interspecies NT However, the development of later stages might require genomic control from transferred donor nucleus. Therefore, even though the involvement of several other factors such as mitochondrial incompatibility, effective development of embryos produced by interspecies NT requires proper genomic activation of donor nucleus after overcoming the cytoplasmic control of recipient oocytes.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1076-1079
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• 2004

Antibiotics are common additives in culture media during in vitro embryo development, but their effects on oocyte maturation in vitro have not been tested. The effects of penicillin, streptomycin and gentamicin on the maturational competence and subsequent development potential of goat follicular oocytes were examined after parthenogenetic activation in vitro. Maturation rates at 24 h after in vitro maturation, and parthenogenetic development at 48 h after activation, were evaluated by observing the protruding first polar body and the 4 cell stage cleavage, respectively. When streptomycin was present in the maturation medium, the percentages of matured oocytes 24 h after activation were significantly (p<0.01) lower than those from the other groups (42.5-45.7% vs. 69.1-73.8%). Penicillin and gentamicin treatment did not affect the maturation rates or the percentages reaching the 4 cell stage 48 h after activation. There was no significant difference in cleavage rates among the different antibiotic treatments 48 h after activation. Therefore, streptomycin suppresses the in vitro maturation of immature goat oocytes, but does not influence their subsequent development.

• Development and Reproduction
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• v.6 no.1
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• pp.17-23
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• 2002

In oocyte retrieval, a vein anesthetic drug is commonly used for induction and maintenance of general anesthesia. Propofol and Thiopental sodium are frequently used for ultrasound-guided transvaginal oocyte retrieval. The present study aimed to assess the effects of Propofol and Thiopental on in vitro fertilization(IVF). Immature porcine oocytes were exposed to various concentrations ot Propofo1 and Thiopental sodium. The rates of oocyte maturation, fertilization and development were observed. The parthenogenetic effects of the anesthetics were also evaluated. The rate of oocyte maturation after exposure to high concentrations of the anesthetics for long time was significantly higher than that of the control. But the rate of fertilization after long-time exposure to the high concentration of the anesthetic drugs was significantly lower than that of the control. The results support that Propofo1 serves like other anesthetics described, as a parthenogenetic activator. Oocytes exposed to Thiopental sodium showed decreased rates of maturation and fertilization. These results suggest that usage of optimum concentration of anesthetic drug is important in increasing the rates of oocyte maturation, fertilization and development in IVF.