• Proceedings of the KSAR Conference
• /
• 2004.06a
• /
• pp.242-242
• /
• 2004

This study was conducted to investigate the effects of various supplements added into maturation medium of immature porcine oocytes on quantity of cytoplasmic lipid droplets(LD), subsequent fertilization and development to the blastocyst stage in vitro. The basic maturation medium was TCM 199 + 1 ㎍/㎖ FSH, 0.57 mM cystein, 10 ng/㎖ EGF and was supplemented various supplements(10% FBS, 10% pFF, 0.4% BSA, 1.0% BSA, 0.4% PVP, 1.0% PVP). (omitted)

• Journal of Embryo Transfer
• /
• v.17 no.1
• /
• pp.61-65
• /
• 2002

This study was carried out to study the viability of oocytes when vitrified at various maturation stages. Bovine cumulus-oocyte complexes were recovered from ovaries at a slaughter and then divided into five groups: control group(unvitrified oocytes), 0 hr. group(composed of oocytes vitrified before the onset of maturation) and 10, 14, and 20 hrs groups(vitrified at 10, 14 and 20 hrs after the onset of maturation, respectively). The oocytes remained vitrified for 24 hrs, and then were thawed in 3$0^{\circ}C$. Survival and cleavage rates were investigated by results of in vitro culture and aceto-orcein staining or FDA test. No difference in the incidence of diploid oocytes was observed among the control, non-vitrified group(3.6%) and oocytes vitrified at 14 hrs(6.7%) or 20 hrs(1.7%). However, more diploid oocytes were detected after vitrification at 0 hr.(26.7%) and 10 hrs(21.7%) post maturation. The survival rate of all vitrified immature oocytes(12.0~38.0%) was low, 48.0% of unvitrified oocytes and oocytes vitrified before maturation or 0~ 10 hrs after the onset of maturation were higher than that of other groups. The overall fertilization and cleavage rates of vitrified immature oocytes (32.3 ~ 64.6% and 4.6 ~ 32.3%) were low, and 55.0% of unvitrified oocytes and the rate of immature oocytes were very higher than that of mature oocytes.

• Clinical and Experimental Reproductive Medicine
• /
• v.18 no.1
• /
• pp.55-61
• /
• 1991

In order to increase the pregnancy rate by means of cryopreservation of the excess oocytes in IVF-ET program, the survival rate of the frozen-thawed oocytes of mouse was examined according to the stages of maturation, cryoprotectants and their treatment. The results were summarized as follows. First, during the continuous treatment with cryoprotectant media, the survival rate of oocytes was higher in DMSO than in PROH, and higher at low temperature($4^{\circ}C$) than at room temperature($25^{\circ}C$). Second, as regard with the maturation of immature(GV-intact) oocytes after treatment with cryoprotectant media, the rate of maturation in DMSO-treated group(52%) was higher than in PROH-treated group(35%). Third, according to the treatment of cryoprotectant media, the survival rate of frozen-thawed oocytes in DMSO-treated group (45%) was higher than in PROH-treated group(29%), and that of oocytes in DMSO 4-step treated group was higher than any other groups. Finally, in the post-thaw oocytes frozen at various stage of maturation, the survival rate of immature oocytes with GV was the highest in all groups. These results suggest that in the cryopreservation of mouse oocytes, DMSO was better than PROH as cryoprotectant, in treatment of cryprotectant the multi-step treatment was better than single-step, and the post-thaw survival rate of oocytes was closely related to the maturity of oocytes. It is assumed that the highest survival rate of mouse oocytes with GV is due to the stability of the structures in nucleus and intracelluar organelles, and of physiological function.

• Reproductive and Developmental Biology
• /
• v.30 no.2
• /
• pp.99-105
• /
• 2006

The growing oocytes become progressively capable of resuming meiosis, and full meiotic competence appear when they are about 80% of the size of fully grown oocytes. As hormonal influences vary at different stages of reproductive cycle, the size of oocytes may vary according to the reproductive stages. The present study was designed to compare the diameter between the ovulated and freshly collected immature canine oocytes. The ovulated oocytes were collected 72 hr after ovulation by oviductal tube flushing by laparotomy under general anesthesia. Immature oocytes were collected by ovarian slicing method. Diameter of all oocytes was measured directly using epiflurescence microscope with a calibrated micro-eyepiece micrometer at ${\times}200$ magnification. The thickness of zona pellucida and diameter of cytoplasm were measured separately and recorded. A total of 2209 zona intact oocytes were collected, among them 628 from anestrus, 675 from follicular, 838 from luteal and 68 by fallopian tubes flushing methods. The average number of oocytes was 104.7, 168.8, 119.7 and 11.3 for anestrus, follicular, luteal and fallopian tubes flushing methods, respectively. The average diameters of the ooplasm and oocyte were significantly varied in different reproductive stages as well as with ovulated oocytes (P<0.05). The average diameter of ooplasm and oocyte was 115.6 and 127.7, 143.0 and 162.0, 134.6 and 150.6, 159.6 and 185.6 for anestrus, follicular, luteal and ovulated oocytes, respectively. Highest number of oocytes with larger diameter could be collected from the follicular and luteal stages. In conclusion, the follicular and luteal ovaries are the best sources of oocytes for canine IVM.

• Journal of Embryo Transfer
• /
• v.26 no.3
• /
• pp.201-207
• /
• 2011

The present study was performed to investigate the survival and subsequent embryonic developmental rate of immature and mature oocytes after vitrification and pronuclear stage embryos after slow-freezing and vitrification. We have also tried to examine the dependency of concentrations (7.5, 15%) and exposure time (5, 10, 20 min) of ED cryoprotectant on developmental rate of pronuclear stage embryos. The developmental rates of 2-ce1l and blastocyst embryos at mature oocytes were significantly (p<0.05) higher than immature oocytes. After slow freezing, vitrification and thawing of pronuclear stage embryo, the survival and developmental rates of blastocysts and hatched blastocysts were significantly (p<0.05) higher after vitrification than after slow-freezing. On contrary, the developmental rates of 2-cell embryos were significantly (p<0.05) higher after slow freezing than after vitrification. The cryopreservation methods of pronuclear stage embryos vitrified by exposed to 7.5% ED solution for 5 minutes was significantly (p<0.05) higher than other experimental group. The results of our study suggest 1hat the developmental rates of mature oocytes have been more successful than immature oocytes during vitrification. Vitrification was more efficient than slow freezing in case of pronuclear stage embryos. The effective cryopreservation method of pronuclear stage embryos was vitrified by exposed to 7.5% ED solution for 5 minutes.

• Proceedings of the KSAR Conference
• /
• 2002.06a
• /
• pp.53-53
• /
• 2002

This study was carried out to verify the incidence of oocytes when vitrified at various maturation stages. Bovine cumulus-oocyte complexes were recovered from ovaries at a slaughter and then divided into five groups: control group(unvitrified oocytes), 0 hr. group(composed of oocytes vitrified before the onset of maturation) and 10, 14, and 20 hrs groups (vitrified respectively at 10, 14 and 20 hrs after the onset of maturation). (omitted)

• 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%).

• Clinical and Experimental Reproductive Medicine
• /
• v.25 no.1
• /
• pp.71-76
• /
• 1998

This study was carried out to examine whether the developmental capacity of bovine immature oocytes frozen ultra-rapidly using electron microscope (EM) grids and EFS30 can be obtained. As freezing solution, we used EFS30 which consisted of 30% ethylene glycol, 0.5 M sucrose, 18% ficoll and 10% FBS added in D-PBS. As criterior of oocyte viability, the rates of maturation, fertilization and embryonic development were determined. The results obtained in this experiment were summarized as follows: When ultra-rapidly frozen immature oocytes were thawed, 43.2% of them were survived. The rates of maturation (84.1%) and normal 2 pronuclei formation (57.5%) of frozen immature oocytes were not significantly different when compared to those of control (92.5, 65.0%). In addition, the rates of $\geq2$-cell (65.0%) and blastocyst formation (30.8%) of freezing group were not significantly different when compared to those of control (73.7, 35.7%). These results demonstrate that developmental capacity of frozen-thawed bovine immature oocytes can be successfully obtained when survived from the ultra-rapid freezing method using EM grid and EFS30.

• Journal of Embryo Transfer
• /
• v.20 no.1
• /
• pp.63-69
• /
• 2005

This study were carried out to evaluate the possibility of nuclear progression of canine immature oocytes, of which was cultured in a reproductive tract, such as oviduct, ovarian bursa and uterus of estrus bitch for 4, 5 and 6 days following immediately collection. Cumulus intact oocytes(COC) fore collected from domestic dog following ovariohysterectomy at local veterinary clinics. In Exp. 1, COCs $of>110\;{\mu}m$ diameter were selected and cultured in vitro at $39^{\circ}C$, $5\%\;CO\_{2} $ in air atmosphere. The nuclear progression of canine oocytes checked at 24, 48 or 72 h after in vitro maturation. There was not increased the nuclear progression to the M II stage depending on culture periods at 24, 48 and 72h $(1.3\%,\;3.7\%\;and\;4.7\%)$. In Exp. 2, to evaluate of nuclear progression of immature oocytes, collected or in vitro cultured oocytes were transfer into a canine reproductive tract (oviduct, ovarian bursa and uterus). The recovery rates of canine oocytes from a reproductive tract after 4 days $(33.7\%)$ in vivo culture were significantly higher than those 5 $(17.7\%)$ 6 day $(3.4\%)$ (P<0.05). The survival rates of collected oocytes after 4 days $(60.0\%)$ were also significantly higher than those of 5 days $(30.2\%)$ and 6 days $(38.9\%)$ (P<0.05). The meiotic resumption rates of canine oocytes were not significantly difference among the culture periods at 4 days $(5.9\%)$, 5 days $(0.0\%)$ and 6 days $(0.0\%)$. These results show that the nuclear progression of canine immature oocytes from in in vivo culture was not affect the nuclear resumption of oocytes.

• Korean Journal of Animal Reproduction
• /
• v.17 no.2
• /
• pp.75-83
• /
• 1993

Purine has been identified in the preparation of follicular fluid and shown an activity in maintaining oocyte meiotic arrest. Therefore this study was performed to examine the inhibitory effect of purine on germinal vesicle break down(GVBD) in the presence and absence of human fetal cord serum(HFCS) or human mature follicular fluid(HMFF), as a protein source, in vitro culture. Immature oocytes(GV stage) were collected from ovaries of 21∼28 days old ICR mice by puncturing the antral follicles with a fine needle, at 48 hrs after PMSG injection. Some of the oocytes were denuded by drawing the cumulus-enclosed(complex) oocytes in and out of a pasteur pipet. Complex oocytes and denuded oocytes were cultured 3 hrs. in T6 media containing 0.75mM adenosine or/and 4mM hypoxanthine, with HFCS or HMFF. Their GVBD rates were observed at every 1 hr. during the culture time. Both adenosine and hypoxanthine have shown a time-dependent inhibitory effect on GVBD in complex and denuded oocytes and the inhibitory effect was maximized in culture medium containing hypoxanthine and adenosine. HFCS and HMFF increased the GVBD rates in the presence of the purines, thus HFCS and HMFF may contain a factor that could reverse the inhibitory effect of purines. Also complex oocytes were more sensitive to not only the inhibitory effect of purines but the promoting action of HMFF on GVBD than denuded oocytes. Therefore it was reconfirmed that granulosa cells play an important part in meiotic arrest and resumption.