• Korean Journal of Animal Reproduction
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• v.17 no.3
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• pp.249-255
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• 1993

Canine follicular oocytes were used to establish a reliable system for maturation and fertilization in vitro. Ovaries were obtained from either slaughter house or hormone-primed bitches of mixed breeds. The oocytes were recovered by mincing the ovaries in M2＋BSA. Good quality of oocyte-cumulus complexes (OCCs) were selected and cultured in TCM 199 containing 15% fetal calf serum(FCS) for 24~56 h in an atmosphere of 5% CO2 at 39$^{\circ}C$. Maturation rate of follicular oocytes was >87% showing metaphase I. Unlike other domestic animals the cumulus expansion did not occur fully in canine OCCs although minimum expansion was found between the cumulus cells and corona radiata cells, the clear nuclear morphology was presented for the first time by rapid staining. The IVM system used in this study may be useful to obtain fully maturated metaphase I oocyte in dog.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.99-105
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• 2018

To determine the differences in the in-vitro ovum maturation process of bovine, we compared the expression of MMPs in these oocytes and cumulus cell throughout oocytes maturated. In an attempt to investigate the effect of MMP activation and inhibitors in total protein of cumulus cell and, oocytes during oocytes maturation, we examined and monitored the localization and expression of MMPs (MMP-2 and MMP-9), TIMPs (TIMP-2 and TIMP-3), as well as their expression profiles (Real-time PCR, Gelatin Zymography and ELISA). Our results that the bovine oocytes MMP-2 and MMP-9 level was significantly associated with the rate of maturity of oocytes (P<0.05). In cumulus cell, MMP-2 was highly expressed in all stages of the oocyte's maturation. The final oocytes maturation exhibited strong gelatinase activity. There was no significant correlation between cumulus cell MMP-9 and the maturation rate of oocytes. However, for the oocyte cytoplasm MMP-9 expression was significant correlation to the maturation oocytes. There was no significant correlation between cumulonimbus cells MMP-9 and oocyte maturation rates; however, for oocyte cytoplasm, MMP-9 expression was significantly correlated with mature oocyte. However, the TIMP-1 and TIMP-2 protein expression patterns are not correlated with the maturation rate of the oocyte. Our results suggest that MMP different expression pattern may regulate the morphological remodeling of oocyte's in the cumulus cell. Further, the MMP-2 expression has a strong relation with a higher maturation rate of the oocyte.

• Korean Journal of Animal Reproduction
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• v.17 no.2
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• pp.93-101
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• 1993

These experiments were carried out to investigate whether zona hardening affect the efficiency of in vitro fertilization in mouse oocytes. The soluble properties for zona pellucida of oocytes matured in vivo, aged oocytes, and ovarian oocytes matured in vitro have been analyzed with proteolytic enzyme, 3mg/ml of $\alpha$-chymotrypsin. The mean solubility(t50) for the zona of unfertilized oocytes, oocytes not fertilized at the first inseminati and in vitro produced zygotes were 10.1, 20.3 and 32.3min., respectively. The t50 for zona lysis of fertilized oocytes was significantly difference than those observed for unfertilized oocytes and oocytes not fertilized at the first insemination(P<0.01). In addition, the t50 of zona in ovulated oocytes with and without cumulus cells incubated for 0, 3, 6, 9 and 12 hr in vitro, t50 were 13.9, 11.1, 20.7 and 28.0min., and 22.3, 21.0, 30.0 and 33.5min., respectively. In these experiments, the zona pellucida showed a gradual increase in resistance to dissolution by $\alpha$-chyjotrypsin with in vitro aging for more than 6 hrs. This effect was greater in cumulus-free as compared to cumulus-intact oocytes. Finally, in cumulus-intact and cumulus-free ovarian oocytes matured for 0, 5, 10 and 15 hr in vitro the t50 of zona pellucida were 3.0, 10.6, 18.4 and 24.5 min., and 3.0, 14.0, 26.2 and 32.0 min., respectively. Clear differences in solubility between the zona pellucida of oocytes matured in vivo and in vitro. This data were found suggest that under in vitro conditions there is a gradual change in the soluble properties of the zona pellucida, particularly in the absence of the cumulus cells.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1260-1266
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• 2001

The effect of protein supplementation, $O_2$ concentration and co-culture on the development of embryos produced by nuclear transfer using cultured cumulus cell was investigated. Recipient oocytes and cumulus cells were obtained from the ovaries of the slaughtered Hanwoo cows. Donor cumulus cells were cultured in Dulbecco's modified Eagle medium containing 10% fetal bovine serum at 5% $CO_2$ in air at $38.5^{\circ}C$. The 1 to 6 passages of cumulus cells were isolated and used as donor cells. The in vitro matured oocytes were enucleated and then the isolated donor cells were introduced. One $15{\mu}s$ pulse of 180 volts was applied to induce the fusion between karyoplast and cytoplast. The fused embryos were activated with $10{\mu}M$ calcium ionophore for 5 min and 2 mM 6-dimethylaminopurine for 3 h. To examine the effect of protein supplementation, nuclear transfer (NT) embryos were cultured in one of the following 4 treatments : 1) CR1aa + 3 mg/ml BSA for 7 days ; 2) CR1aa + 10% FBS for 7 days ; 3) CR1aa + 1.5 mg/ml BSA + 5% FBS for 7 days ; and 4) CR1aa + 3 mg/ml BSA for first 3 days and then CR1aa + 1.5 mg/ml BSA + 5% FBS for 4 days. Culture took place at 5% $CO_2$, 5% $O_2$ and 90% $N_2$ at $38.5^{\circ}C$. Although there were no significant differences in cleavage rate among different protein supplements, the rates of blastocyst formation were significantly different. When NT embryos were cultured in the medium supplemented with only BSA, they could develop to only morula not to blastocyst. However, when FBS was supplemented, NT embryos developed to blastocyst stage. In order to investigate the effect of $O_2$ concentration and co-culture, NT embryos were cultured in CR1aa + 1.5 mg/ml BSA + 5% FBS with or without cumulus cell co-culture at an atmosphere of 5% $CO_2$ in air (20% $O_2$) or 5% $CO_2$, 5% $O_2$, 90% $N_2$ (5% $O_2$) at $38.5^{\circ}C$ for 7 days. The percentage of blastocyst development was significantly higher when the NT embryos were cultured at an atmosphere of 5% $O_2$ than that of 20% $O_2$ (p<0.05). However, there was no significant difference between with and without cumulus cell co-culture at an atmosphere of 5% $O_2$ or 20% $O_2$. Fifty embryos were transferred to 25 recipients and 5 recipients were pregnant at 100 days. From 5 pregnant cows, only one cow was delivered of female twin. In conclusion, the embryos reconstructed by enucleation of metaphase II oocytes and introduction of the cycling and quiescent cumulus donor cells in Hanwoo had developmental potential to term after embryo transfer to recipient cows.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.109-113
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• 2003

The study was carried out to investigate the effects of morphology, preservation and reproductive cycle of oocytes in vitro maturation of cats oocytes and development of IVM embryos. The results were summarized as follows : 1. Nuclear status of GV and MI of in vitro cultured(24 h) oocytes with and whithout cumulus cells were 74.3% and 25.7%, 28.6% and 11.4%, 77.1% and 5.7%, respectively, The rate of oocytes with cumulus cells was higher than that of denuded oocytes. 2. Nuclear status of GV and MI of in vitro cultured(24 h) oocytes recovered from ovaries collected at different stages of the reproductive cycle(inactive, follicular and luteal) were 88.6% and 6.5%, 60.0% and 11.4%, 77.1% and 5.7%, respectively. 3. Nuclear status of fresh and salts-stored oocytes with and whithout cumulus cells were 74.3%, 25.7% and 37.1%, 11.4% and 57.1%, 13.3%, 17.1%, 3.3%, respectively. The rate of oocytes with cumulus cells(13.3%∼74.3%) was higher than that of denuded oocytes(3.3%∼57.1%).

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.53-57
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• 2004

The study was carried out to investigate the effects of morphology, reproductive cycle, incubation time and activation of oocytes on in vitro maturation of cat oocytes and development of IVM/IVF embryos. The results were summarized as follows: 1. When recovered from ovaries collected at different stages of the reproductive cycle (inactive, follicular and luteal stage), the developmental rates of oocytes to GV and MI stage were 72.5% and 27.5%, 57.5% and 7.5%, 62.5% and 17.5%, respectively. 2. The developmental rates of oocytes with cumulus cells to GV and MI stage in different conditions of incubation (5% $CO_2$ , 95% $O_2$ and 10% $CO_2$, 90% $O_2$) were 70.0% and 27.5%, 52.5% and 20.0%, 55.0% and 12.5%, respectively. 3. The developmental rates to GV and MI oocytes when cultured at different time of incubation (17∼20, 21∼24, 25∼28 and 29∼32 h) were 67.5% and 20.0%, 67.5% and 30.0%, 62.5% and 22.5%, 65.0% and 15.0%, respectively. 4. The fertilization and cleavage rates of freshly collected oocytes with and without cumulus cells were 72.5% and 25.0%, 37.5% and 7.5%, respectively. The rates were greater in oocytes with cumulus cells than those without cumulus cells. 5. The fertilization and cleavage rates of oocytes recovered from ovaries collected at different stages of the reproductive cycle (inactive, follicular and luteal stage) were 75.0% and 25.0%, 40.0% and 7.5%, 50.0% and 15.0%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1545-1552
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• 2013

This study was conducted to investigate the effects of Trichostatin A (TSA) on cumulus expansion during mouse oocyte maturation. TSA treatment inhibited cumulus expansion and significantly reduced the cumulus expansion index (CEI) (p<0.05). To determine the underlying mechanism, the expression levels of several key factors that play crucial roles in cumulus expansion including components of extracellular matrix (ECM) (Has2, Ptgs2, Ptx3, and Tnfaip6) and Growth differentiation factor 9 (GDF9) were measured in control and TSA treated samples by real-time PCR. The effect of TSA on ERK phosphorylation (p-ERK1/2) in cumulus cells and GDF9 protein level in fully grown oocytes (FGOs) were detected by Western blotting. The expression levels of the ECM genes were significantly decreased (p<0.05) by TSA treatment while GDF9 expression did not response to TSA (p>0.05). TSA treatment blocked the activation of ERK1/2 (p<0.05) and had no significant effect on GDF9 protein expression (p>0.05). Collectively, these results suggested that TSA treatment altered ECM gene expression and blocked ERK1/2 activation to inhibit cumulus expansion in the mouse.

• Development and Reproduction
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• v.5 no.2
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• pp.123-129
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• 2001

When mammalian oocytes undergo maturation, cumulus cells surrounding the oocyte exhibit remodeling of their structure known as cumulus expansion. Many molecules including hyaluronic acid participate in this remodeling. The present study aimed to investigate a possible existence of matrix metalloproteinases(MMPs) in the extracellular matrix(ECM) of human oocyte-cumulus complex. ECM was extracted from the human oocyte-cumulus complex. Gelatin gel zymogram of ECM exhibited 7 gelatinases having molecular weight of 300kDa, 240kDa, 200kDa, 180kDa, 116kDa, 97kDa, and 84kDa. This gelatinase profile was very different from that of ovarian mural granulosa cell extract or white blood cell extract, indicating that the oocyte-cumulus complex donating ECM was free from other than cumulus cells. When ethylenediaminetetraacetic acid or 1', 10'-phenanthroline was added to the reaction buffer during zymographic development, almost gelatinase activities were abolished, suggesting that they were MMPs. Following incubation of ECM in the presence of aminophenylmercuric acetate, an activator of proMMPs, 4 gelatinases of 240kDa, 180kDa, 97kDa, and 84kDa disappeared with the concomitant appearance of 80kDa, 65kDa, and 60kDa gelatinases. Based upon these observation, it is suggested that ECM of the human oocyte-cumulus complex consists of gelatinases, presumed to be MMP-2 and MMP-9 isoforms.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.155-161
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• 2012

Germ cell-specific hyaluronidases such as sperm adhesion molecule 1 (SPAM1) and hyaluronoglucosaminidase 5 (Hyal5) are in part responsible for dispersal of the cumulus cell mass, which is a critical step in establishing fertilization in mammals. In this study, we identified two testis-hyaluronidases, SPAM1 and Hyal5, in hamster and rat. These two genes were expressed specifically in the testis. At the protein level, hamster SPAM1 and Hyal5 display 78.7% and 75.4% identity with mouse SPAM1 and Hyal5. Further, the activity of the enzymes with respect to cumulus cell dispersion did not differ, although we observed that the enzymatic activity differed in pH range. These studies suggest that different sperm hyaluronidases are capable of dispersing the cumulus cell mass despite differences in enzyme activity.

• Korean Journal of Animal Reproduction
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• v.22 no.1
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• pp.51-59
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• 1998

This study was undertaken to investigate the effects of ITS and EGF on embryonic development of in vitro matured and fertilized bovine oocytes in culture medium su, pp.ementing with or without calf serum. When fertilized oocytes were cultured in TCM-199 containing 0, 0.1, 0.5 and 1.0\ulcorner/ml ITS with 5% calf serum, the rates of development to blastocyst stage and the cell number of blastocysts were not significantly different among all treatments. And also monolayer of cumulus/granulosa cells prepared in containing calf serum and ITS were no beneficial effects of embryonic development. On the other hand, when EGF was su, pp.imented to TCM-199 containing calf serum or calf serum free, embryonic development rates(24.0 2.8% to 29.2 1.7% or 8% to 9%) and cell number of blastocysts(p<0.05) were significantly increased compared with EGF-free(22.1 2.1 or 1.0%, p<0.05). But when fertilized oocytes were cultured with cumulus/granurosa cells in TCM-199 containing EGF and calf serum, the rate of embryos development to the blastocyst stage and cell number of blastocysts were not significantly different compared with EGF-free and any concentrations. These results showed that ITS and EGF was not improved the development of bovine embryo in vitro matured and in vitro fertilized with calf serum and/or monolayer of cumulus/granulosa cells.