• Clinical and Experimental Reproductive Medicine
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• 제27권4호
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• pp.345-351
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• 2000

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.352-358
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• 2016

Quercetin (QT) and taxifolin (TF) are structurally similar plant-derived flavonoids that have antioxidant properties and act as free radical scavengers. The objective of this study was to investigate effects of QT and TF on nuclear maturation of porcine oocytes. Effects of TF at 0, 1, 10, and $50{\mu}g/mL$ on oocyte nuclear maturation (polar body extrusion) were investigated. After incubation for 44 h, there were no significant differences between the treatment and control groups except in the $50{\mu}g/mL$ group which was significantly lower (59.2%, p<0.05) than the other groups (control: >80%). After parthenogenetic activation, further in vitro development of QT- or TF-treated vs control oocytes was investigated. A significantly higher proportion of QT-treated ($1{\mu}g/mL$) oocytes developed into blastocysts compared to controls (24.3% vs 16.8%, respectively); however, cleavage rate and blastocyst cell number were not affected. The TF-treated group was not significantly different from controls. Levels of reactive oxygen species (ROS) and intracellular glutathione (GSH) in oocytes and embryos in a culture medium supplemented with QT or TF were measured. Both treatment groups had significantly lower (p<0.05) levels of ROS than controls, however GSH levels were different only in QT-treated oocytes. We conclude that exogenous flavonoids such as QT and TF reduce ROS levels in oocytes. Although at high concentration ($50{\mu}g/mL$) both QT and TF appear to be toxic to oocytes.

• 한국수정란이식학회지
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• 제28권4호
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• pp.361-371
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• 2013

The present study assessed the effect of FSH and LH on oocyte meiotic, cytoplasmic maturation and on the expression level and polyadenylation status of several maternal genes. Cumulus-oocyte complexes were cultured in the presence of FSH, LH, or the combination of FSH and LH. Significant cumulus expansion and nuclear maturation was observed upon exposure to FSH alone and to the combination of FSH and LH. The combination of FSH and LH during entire IVM increased the mRNA level of four maternal genes, C-mos, Cyclin B1, Gdf9 and Bmp15, at 28 h. Supplemented with FSH or LH significantly enhanced the polyadenylation of Gdf9 and Bmp15; and altered the expression level of Gdf9 and Bmp15. Following parthenogenesis, the exposure of oocytes to combination of FSH and LH during IVM significantly increased cleavage rate, blastocyst formation rate and total cell number, and decreased apoptosis. In addition, FSH and LH down-regulated the autophagy gene Atg6 and upregulated the apoptosis gene Bcl-xL at the mRNA level in blastocysts. These data suggest that the FSH and LH enhance meiotic and cytoplasmic maturation, possibly through the regulation of maternal gene expression and polyadenylation. Overall, we show here that FSH and LH inhibit apoptosis and autophagy and improve parthenogenetic embryo competence and development.

• Clinical and Experimental Reproductive Medicine
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• 제44권1호
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• pp.15-21
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• 2017

Objective: The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of $Ca^{2+}$ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). Methods: MII-stage and arrested MI-stage mouse oocytes after IVM were fertilized, and then embryonic development was monitored. Blastocysts from each group were transferred into 2.5 days post-coitum pseudo-pregnant ICR mice. MI oocytes after IVM were treated with a $Ca^{2+}$ chelator to investigate the effect of $Ca^{2+}$ oscillations on their maturation. Results: As insemination time increased, the number of oocytes in the MI group that reached the MII stage also increased. The blastocyst rates and total cell numbers in the MII group were significantly higher than in the MI group. No pregnancy occurred in the MI group, but 10 pregnancies were achieved (10 of 12) in the MII group. The proportion of MI oocytes that matured to MII oocytes after fertilization was significantly higher in the non-treated group than in the $Ca^{2+}$ chelator-treated group. Conclusion: The findings that a higher proportion of MI-arrested oocytes progressed to MII after fertilization and that the MI-to-MII transition was blocked by $Ca^{2+}$ chelator treatments before fertilization indicate that the maturation of MI oocytes to MII oocytes is associated with intracellular $Ca^{2+}$ oscillations driven by fertilization.

• Reproductive and Developmental Biology
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• 제36권3호
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• pp.141-145
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• 2012

The present study was conducted to develop a simple method for porcine oocyte maturation without $CO_2$ regulation. In experiment 1, we evaluated that the effect of $CO_2$ non-supplement on porcine oocyte maturation. Cumulusoocyte complexes (COCs) were collected from 2~6 mm follicles and divided into three groups (Control, tube-$CO_2$, and tube-non-$CO_2$). For control, COCs were cultured in 4-well multidish in a $CO_2$ incubator. For tube-$CO_2$, COCs were cultured in a round-bottom tube in a $CO_2$ incubator, and for tube-non-$CO_2$, COCs were cultured in a round-bottom tube sealed tightly without $CO_2$ supplement in a dry incubator. The proportion of oocytes reached to metaphase II (M-II) was not significantly different among three groups (87.9% to 91.4%). In experiment 2, we evaluated the effect of $CO_2$ non-supplement during oocyte maturation on development of embryos. Oocytes with a polar body were divided into two groups (Control and tube-non-$CO_2$) and applied 1.1 kV/cm or 1.2 kV/cm voltages for parthenogenetic activation. After activation, embryos were cultured for 6 days and examined the development. The proportion of embryos cleaved was not significantly different among treatment (86.3% to 91.5%). The proportion of embryo reached to blastocyst stage was not significantly different among treatment (13.9% to 25.2%). The cell number of blastocysts was not significantly different among treatment (29.0 to 32.4). In conclusion, oocytes cultured in a dry incubator without $CO_2$ supplement have enough competence to development after parthenogenetic activation. These results would be useful for transporting oocytes or embryos a long distance.

• 한국수정란이식학회지
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• 제20권2호
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• pp.105-112
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• 2005

본 연구는 재래산양에서 복제 수정란의 생산효율을 향상시키기 위한 기초 자료를 제시하고자 체세포 핵이식을 실시하여 공핵세포의 종류, 핵이식란의 활성화 처리 방법 및 수핵난자의 조건이 체외발달율에 미치는 영향을 조사, 검토하여 핵이식란 생산을 위한 최적의 조건을 규명하고자 실시하였다. 공핵세포의 종류에 따른 핵이식란의 체외발달율은 융합이 이루어진 핵이식란의 활성화 처리 후 분할율은 귀 유래 섬유아세포를 공핵세포로 사용하였을 때가 $40.5\%$로서 태아 유래 섬유아세포를 공핵세포로 사용하였을 때의 $55.5\%$와 유의적인 차이가 없었다. 또한 상실배 또는 배반포기로의 발달율도 각각 $6.7\%$ 및 $16.0\%$로서 유의적인 차이가 없었다. 핵이식란의 활성화 방법에 따른 체외발달율은 ionomycin+6-DMAP 처리를 하였을 때 분할율은 $79.0\%$로서 전기자극을 주었을 때의 $9.5\%$보다는 유의적(P<0.05)으로 높았다. 상실배 또는 배반 포기로의 발달율도 ionomycin+6-DMAP 처리를 하였을 때는 $15.6\%$가 발달하였으나, 전기 자극을 주었을 때는 4-세포기 이후로의 발달이 전혀 이루어지지 않았다. 체세포 핵이식란은 단위발생란에 비하여 분할율$(66.1\%\;vs\;59.18\%)$ 및 상실배 또는 배반포배로의 발달율$(19.0\%\;vs\;0.0\%)$이 유의적 (P<0.05)으로 낮았다. 단위발생란의 분할율은 체내 성숙난자에서 $86.8\%$로서 난포란의 $69.0\%$보다는 유의적(P<0.05)으로 높았다 단위발생란의 상실배 또는 배반포기로의 발달율에 있어서도 체내 성숙난자$(50.0\%)$가 난포란$(23.6\%)$보다 유의적 (p.<0.05)으로 발달율이 높았다. 이상의 결과로 볼 때 재래산양의 체세포를 이용한 복제수정란의 생산효율을 향상시키기 위해서는 다수의 난자 확보를 위한 과배란처리 방법의 개선, 난포란의 이용효율 개선 및 활성화 처리방법 등이 확립되어야 하며, 후기배로의 발달율 향상을 위해서는 최적의 체외 배양조건 확립이 시급한 것으로 생각된다.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.261-267
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• 2012

The technique of SCNT is now well established but still remains inefficient. The in vitro development of SCNT embryos is dependent upon numerous factors including the recipient cytoplast and karyoplast. Above all, the metaphase of the second meiotic division (MII) oocytes have typically become the recipient of choice. Generally high level of MPF present in MII oocytes induces the transferred nucleus to enter mitotic division precociously and causes NEBD and PCC, which may be the critical role for nuclear reprogramming. In the present study we investigated the in vitro development and pregnancy of White-Hanwoo SCNT embryos treated with caffeine (a protein kinase phosphatase inhibitor). As results, the treatment of 10 mM caffeine for 6 h significantly increased MPF activity in bovine oocytes but does not affect the developmental competence to the blastocyst stage in bovine SCNT embryos. However, a significant increase in the mean cell number of blastocysts and the frequency of pregnant on 150 days of White-Hanwoo SCNT embryos produced using caffeine treated cytoplasts was observed. These results indicated that the recipient cytoplast treated with caffeine for a short period prior to reconstruction of SCNT embryos is able to increase the frequency of pregnancy in cow.

• 한국수정란이식학회지
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• 제29권2호
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• pp.101-109
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• 2014

Matrix Metalloproteinases (MMP)-2 and -9 are participated in embryo development, implantation, remodeling of epithelial cell and ovulation. The objective of this study is to evaluate an impact of MMP2 and MMP9 on embryonic developmental competence as well as gene expression profiles of in vitro-produced bovine embryos. After in vitro fertilization, embryos of all groups were transferred into IVC-2 medium treated with MMP2 and MMP9 to check the optimum concentration on the basis of embryo development competence and cell numbers. The optimum concentrations for MMP2 and 9 were 1,200 ng/ml and 300 ng/ml. The blastocyst development competence was not different among 1,200 ng/ml of MMP2 vs. 300 ng/ml of MMP9 vs. combined MMP2 + 9 vs. control groups ($41.46{\pm}10.66$ vs. $37.73{\pm}8.92$ vs. $45.11{\pm}11.41%$ vs. $41.59{\pm}11.88$, respectively). Furthermore, the developmental competences to hatching and hatched blastocysts were not also different among the same groups ($79.84{\pm}12.63$ vs. $83.3{\pm}17.46$ vs. $78.55{\pm}14.48%$ vs. $72.02{\pm}14.09$). In addition, total cell number was significantly (p<0.05) greater in blastocyst treated with MMP9 300 ng/ml among all treatment groups. On the other hand, there was no significant difference of ICM vs. TE ratio in all groups. The expression of five out of six genes (i.e., MMP2, MMP9, IFNt, SSLP1 and HNRNPA2B1) was different among the groups. The expression of IFNt and HNRNPA2B1 genes was significantly greater in MMP9 (p<0.05), but there was no difference of MMP9 expression between MMP2 and MMP9 group (p>0.05). The normalized expression of MMP2 and SSLP1 was greater in MMP2 than other groups (p<0.05). In conclusion, MMPs treatment during IVC-2 medium was remarkably effected on blastocyst developmental competence and gene expression profiles that are related to embryo quality and implantation.

• Reproductive and Developmental Biology
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• 제29권3호
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• pp.201-205
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• 2005

본 연구는 아미노산의 첨가가 돼지 수정란의 체외 발달율에 미치는 영향을 구명하고자 PEF가 함유된 NCSU-23을 기본배지로 체외성숙 및 체외배양액을 조성한 후 EA(Essential amino acid), NA(Non-essential amino acid) 및 EANA(EA+ NA)를 첨가하여 체외성숙, 체외수정 및 체외발달에 미치는 영향을 조사하였다. 체외성숙 배지에 아미노산을 첨가한 결과 MH 단계까지의 체외성숙율은 NA 첨가군이 $83.3\%$로 대조구 $70.0\%$에 비하여 유의적으로(p<0.05) 높았다. 그러나 체외 수정 이후의 배 발달율과 수정율에서는 아미노산 첨가군과 무첨가군 사이에 유의적인 차이는 없었다. 체외배양액에 아미노산을 첨가한 후 배반포의 내부세포괴(ICM) 세포와 영양배엽(TE) 세포의 발달에 미치는 영향을 조사한 결과, ICM에서는 유의차를 발견할 수 없었으나 TE 세포는 EANA 처리구가 $18.0{\pm}0.5$개로 대조구 $16.09{\pm}0.56$개에 비해 유의적(p<0.05)으로 많았다. 총세포수에서도 EANA 처리구가 $50.0{\pm}1.0$개로 대조구 $44.2{\pm}1.1$개보다 유의적(p<0.05)으로 많았다. 이상의 결과를 종합할 때, 돼지의 체외수정란 생상에 있어서 아미노산의 첨가는 배반포로의 발달율에는 영향을 미치지 못하였으나 체외성숙율을 높이고 배반포의 세포수 향상에 도움을 주는 것으로 판단된다. 특히, 영양배엽(W) 세포의 발달율이 높은 것으로 보아 아미노산의 첨가는 돼지수정란의 착상에 도움을 줄 것이라 기대된다.

• 한국가축번식학회지
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• 제26권3호
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• pp.215-221
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• 2002

본 연구는 일정량의 항산화제(NAC, ebselen 및 GSH)와 성장인자(EGF, PDGF)의 혼합첨가가 돼지 체외수정란의 체외배양에 미치는 영향을 검토하였다. 1. NCSU 23 배양액에 NAC 1nm과 NAC에 EGF 100ng/$m\ell$비 및 PDGF 5ng/$m\ell$를 각각 혼합 첨가하여 체외배양을 실시한 결과, 상실배기 이상 발육된 체외발육율은 각각 28.1%, 32.3% 및 35.3%로서 NAC와 PDGF 혼합처리구가 대조 구보다 다소 높은 체외발육율을 나타냈으나 통계적 유의성은 없었다(P>0.05). 2. NCSU 23 배양액에 ebselen 10$\mu\textrm{m}$과 ebselen에 EGF 100ng/$m\ell$ 및 PDGF 5ng/$m\ell$를 각각 혼합첨가하여 체외발육율을 조사한 결과, 상실 배기 이상 발육된 수정란의 체외발육율은 각각 17.8%, 36.9% 및 40.3%로 ebselen과 성장인자의 혼합처리구가 대조구보다 통계적 유의하게 높은 체외발육율을 나타냈다(P<0.05). 3. NCSU 23 배양액에 GSH 100$\mu\textrm{m}$과 GSH에 EGF 100ng/$m\ell$ 및 PDGF 5ng/$m\ell$를 각각 혼합 첨가배양하여 상실배기 이상 발육된 수정란의 체외발육율은 각각 24.4%, 30.5% 및 27.7%로 GSH과 EGF 혼합처리구가 여타구보다 다소 높은 체외발육율을 나타냈지만 통계적 유의성은 없었다(P>0.05). 4. 모든 처리구에서 배반포기 수정란의 세포수는 커다란 차이가 인정되지 않았으나(P>0.05), 체외배양액에 ebselen과 성장인자를 혼합첨가하여 체외배양한 처리구에서는 대조구에 비해 통계적으로 유의하게 높은 세포수를 나타냈다.(P<0.05).