• 한국가축번식학회지
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• 제21권2호
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• pp.111-116
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• 1997

We determined the effects of follicular fluid fractions in the maturation medium on bovine oocyte maturation, fertilization and subsequent development, as well as on number of cells in blastocysts following culture. Follicular fluid and oocytes from bovine follicles less than 5 mm in diameter were collected from the ovaries of slaughtered cows. Follicular fluid was separated into different molecular weight fractions by untrafiltration through a membrane using a centrifuge at 500$\times$g, for 2h. For the maturation medium, follicular fluid fractions (30%, v/v), whole fluid (30%) or PVP(3mg/ml) were added to TCM 199(0.1$\mu\textrm{g}$/ml estradiol-17$\beta$, 100IU hCG). After maturation for 24h, oocytes were fertilized in vitro with bull frozen-thawed spermatozoa and cultured on a monolayer of granulosa cells for 9 days after fertilization. There were no differences in maturation rates or fertilization rates among any maturation conditions. The rates of development to >2-cell stage of the oocytes were significantly decreased when fraction of follicular fluid below 10,000 MW were added into maturation medium, compared with control and fraction above 10,000 MW(26.0% vs 40.8% to 64.0%, respectveily. p<0.01). Likewise, the rates of development to blastocysts of fertilized oocytes were significantly decreased in maturation medium containing fraction of follicular fluid (<10,000 MW). The average cell number of blastocysts derived from oocytes that matured in the fraction(>10,000 MW) of follicular fluid was 154.7$\pm$13.7. These embryos contained more cells than those matured in whole follicular fluid, or the fraction(<10, 000 MW) of follicular fluid or control(107.0$\pm$8.4, 91.8$\pm$11.8 and 95.8$\pm$6.2, respectively). In conclusion, we found that fractions of follicular fluid contained factors stimulating or inhibiting oocyte cytoplasmic matruation. These suggest that a factor(s) inducing cytoplasmic maturation of oocytes may exist in >10,000 MW fraction of follicular fluid.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.117-117
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• 2002

The oocytes from most of animal species accumulate genetic information and other necessary materials during oogenesis for the later use in the early development. Over the years oocyte maturation has been studied extensively both in vitro and in vivo. Particularly, maturation of follicular oocyte in vitro becomes one of the important tools for the studies of basic cell biology, the in vitro technology of animal production, and in particular, the somatic cell cloning by nuclear transfer. We examined meiotic maturation and cumulus expansion in the presence of translation or transcription inhibitors for varying periods of in viかo maturation (IVM) of pig oocyte. In Experiment 1, the results revealed that translation and transcription inhibitors inhibited cumulus expansion and meiotic maturation during 35h of IVM. However, 50 to 60% of the oocytes underwent nuclear maturation without cumulus expansion during 75h of IVM. The rest of the oocytes were arrested at metaphase I (40-50%) in the presence of the inhibitors. In Experiment II, the OCCs were exposed to the drugs only for 15h to examine translation and transcription inhibitors on cumulus expansion and meiotic maturation. Transcription inhibitors for 15h did not arrest meiotic maturation when the oocytes were cultured for subsequent, necessary period of IVM, whereas cumulus expansion was completely inhibited, suggesting that initial 15h is critical transcription activity far cumulus expansion. Translation inhibitors for 15h exposure did not alter cumulus expansion and meiotic maturation during subsequent culture in the absence of the drugs. In Experiment III, the OCCs were exposed to the drugs only for later 30h to examine the influence of transcription and translation inhibitors on oocyte maturation. Interestingly, all meiotic maturation underwent normally with full expansion of cumulus. Similar results were obtained from Experiment IV where 5h of exposure from 15 to 20h of IVM culture to the drugs was performed and subsequently cultured for same period in fresh medium. Taken there results together, both transcription and translation are necessary for nuclear maturation and cumulus expansion, and first 15h IVM for cumulus expansion is critical. The arrested oocytes by the drugs were still capable of undergoing nuclear maturation, although cumulus expansion was affected.

• 한국가축번식학회지
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• 제21권1호
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• pp.19-23
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• 1997

This present study was carried out to examine the effect of maturation media and liquid boar semen on in vitro maturation and feritilization of pig oocytes. The results obtained were as follows : When the oocytes were cultured for 36∼42 hours in mTCM-199, Waymouth MB 725/1 and mTLP-PVA medium, the maturation rates were 90%, 92% and 88%, respectively. The sperm penetration rates of pig oocyte matured in vitro were 87%(mTCM-199), 90%(Waymouth MB 725/1) and 86%(mTLP-PVA), respectively. The rates of nuclear maturation and fertilization of pig oocytes among three different media did not differ. However, the rate of male pronucleus formation of pig oocytes was significantly higher in pig oocytes matured in Waymouth MB 725/1(91%) than oocytes matured in mTCM-199(66%) and mTLP-PVA(62%) medium (P<0.05). When the collected sperm-rich fraction without diluent was used fro in vitro fertilization in mTCM-199 fertilization medium, the fertilization rate was 87.9%. However, when the liquid boar semen diluted with B tschwiler diluent was used at day 3 and 5 after dilution, the fertilization rate was 40.8% and 0.0%, respectively.

• 한국수정란이식학회지
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• 제9권1호
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• pp.1-6
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• 1994

This experiment was investigated the effect of presence of granulosa cells from follicles of different size on bovine oocyte maturation, cleavage and development to late stage. The nuclear and cytoplasmic maturation of oocytes in the IVM-IVF system are critical for subsequent embryo development. Granulosa cells when the co-cultured with oocytes may interact with cumulus-oocytes complexes and influence the development competence of the oocytes. Granulosa cells from medium (2~6 mm) and large(>1O mm) size follicles were recovered by aspiration, washed 3 times by centrifugation at 500 x g for 5 min. and used for co-culture at a concentration of 2~3 x 106 cells/mi. The oocytes were matured in vitro (IVM) for 24 hrs. in TCM-199 supplemented with 35 $\mu$g/ml FSH, 10 $\mu$g/ml LH, 1 $\mu$g/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% $CO_2$ in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (I VC) with bovine oviductal epithelial cells for 7 to 9 days. The assessment of maturation revealed that Grade J oocytes showed significantly(P

• Reproductive and Developmental Biology
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• 제28권2호
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• pp.95-99
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• 2004

본 연구는 미성숙돼지 난모세포의 체외 성숙에 있어서 myo-inositol의 영향을 알아보기 위하여 실시하였다. 미성숙 돼지 난모세포을 myo-inositol을 포함하는 또는 포함하지 않은 체외 성숙배지에서 44시간 체외 성숙을 유도하였을 때 성숙율은 myo-inositol을 첨가한 성숙배지에서 성숙시킨 실험구에 유의하게 높았다(P<0.05). Myo-inositol 에 의한 성숙율 향상에 있어서 난구세포의 영향을 알아보기 위하여 난구세포의 치밀도에 따라 분류하여 미성숙 난모세포을 myo-inositol을 포함하는 체외 성숙배지에서 배양하였을 때 난구세포가 치밀한 미성숙 난모세포에서가 더 높은 성숙율을 나타내었다(P<0.05). 그러나 난구세포가 치밀하지 않은 미성숙 난모세포도 myo-inositol을 포함하는 성숙배지에서 배양하면 성숙율은 대조구에 비하여 유의하게 높았다(P<0.05). 이러한 결과는 돼지 난모세포의 체외 성숙배지에 myo-inositol의 첨가는 체외 성숙율을 향상시킬 수 있음을 나타내고 있다.

• Journal of Animal Science and Technology
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• 제57권8호
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• pp.27.1-27.6
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• 2015

This study was designed to investigate the effects of ${\alpha}$-tocopherol and granulosa cells monolayer on nuclear maturation and cleavage rates of ovine cumulus-oocyte complexes (COCs). The COCs (n = 2814) were matured in maturation medium supplemented with various concentration of ${\alpha}$-tocopherol (0, 5, 10, $15{\mu}g/ml$), oocytes were incubated at $39^{\circ}C$ with 5 % $CO_2$ for 24 h in three culture systems: (a) maturation medium (MM; n = 884), (b) co-cultured with granulosa cells (CG; n = 982) and (c) co-cultured with granulosa cells and cells were further cultured in MM for 12 h (CG + 12hMM; n = 948). Our results showed that ${\alpha}$-tocopherol had no effect on GVBD and MII as compared to control group, but when ${\alpha}$-tocopherol added to maturation medium the rate of cleavage decreased. This indicates interaction of above mentioned factors in any of the treatments showed no significant differences on the rate of maturation and cleavage stages (MII, GVBD and cleavage) (p > 0.05). The oocytes co-cultured with granulosa cells for 24 h had beneficial effects on cleavage rate. The maximum MII and cleavage rates were achieved when oocytes had extra 12 h culture in the maturation medium without granulosa cells. Results also showed our modified co-culture system (CG + 12hMM), improved rates of MII and the cleavage in comparison with other studied maturation systems.

• 한국발생생물학회지:발생과생식
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• 제17권1호
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• pp.63-72
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• 2013

A specific inhibitor of RNA polymerase II, ${\alpha}$-amanitin is broadly used to block transcriptional activities in cells. Previous studies showed that ${\alpha}$-amanitin affects in vitro maturation of cumulus-oocyte-complex (COC). In this study, we evaluated the target of ${\alpha}$-amanitin, and whether it affects oocytes or cumulus cells (CCs), or both. We treated ${\alpha}$-amanitin with different time period during in vitro culture of denuded oocytes (DOs) or COCs in comparison, and observed the changes in morphology and maturation status. Although DOs did not show any change in morphology and maturation rates with ${\alpha}$-amanitin treatment, oocytes from COCs were arrested at metaphase I (MI) stage and CCs were more scattered than control groups. To discover causes of meiotic arrest and scattering of CCs, we focused on changes of cumulus expansion, gap junctions, and cellular metabolism which to be the important factors for the successful in vitro maturation of COCs. Expression of genes for cumulus expansion markers (Ptx3, Has2, and Tnfaip6) and gap junctional proteins (Gja1, Gja4, and Gjc1) decreased in ${\alpha}$-amanitin-treated CCs. However, these changes were not observed in oocytes. In addition, expression of genes related to metabolism (Prps1, Rpe, Rpia, Taldo1, and Tkt) decreased in ${\alpha}$-amanitin-treated CCs but not in oocytes. Therefore, we concluded that the transcriptional activities of CCs for supporting suitable transcripts, especially for its metabolic activities and formation of gap junctions among CCs as well as with oocytes, are important for oocytes maturation in COCs.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1404-1410
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• 2008

This study was performed to clarify whether the variation of stress related heat shock protein 70 (HSP70) (GenBank X68213) gene was associated with the nuclear morphological change of in vitro maturation and in vitro capacitation in oocytes of pig ovaries obtained at the slaughterhouse. The nucleic acid substitution of C to G at the 483rd position was found out in HSP70 K1 (290-512) from X68213. The ovaries were categorized into CC, CG, and GG genotypes using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) (BsiHKA I). After the second in vitro maturation of immature fresh oocytes, the relation of nuclear morphological change in oocytes with the genotype of HSP70 K1 gene was such that the MII ratios of the genotype GG and CG (46.93% and 42.20%, respectively) were significantly higher than that of the CC genotype (10.71%) (p<0.05). With respect to in vitro maturation of frozen-thawed oocytes by an open pulled straw (OPS) method, the percentage of oocytes matured to MII stage of the CG genotype showed a higher trend than CC and GG genotypes. After the in vitro maturation of immature fresh oocytes and frozen-thawed oocytes by the OPS method, the relation of the pronuclei change in oocytes matured in vitro with HSP70 genotype was assessed, and the result showed that the enlarged sperm heads (ESH) of matured fresh oocytes and frozen-thawed oocytes were 80.0% and 60.0% in the CC genotype, respectively. The CC genotype group had a significantly higher rate of ESH than the CG and the GG genotype group (p<0.05). The ratios of polyspermic invasion were not different among HSP70 of the three genotypes. It was considered that the rate of in vitro maturation of fertilized oocytes was expected to differ according to genotype of the stress related gene.

• 한국가축번식학회지
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• 제27권1호
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• pp.35-44
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• 2003

The present study was performed to investigate the first polar body(PB) extrusion during in-vitro maturation(IVM) and to examine the effect of different maturation time on the embryo development of Korean Native Cows(KNC) with regard to blastocyst(BL) cell numbers and pregnancy rates. PB extrusion did not take place for the first 12 hours(hr) of IVM, and most of KNC oocytes extruded PB from 14 to 20 hr after the onset of maturation. There was no significant difference in cleavage and 8-cell stage rates among the treatment groups, but BL and BL/8-cell rates were significantly higher(P<0.05) in 18 hr maturation group(31.0$\pm$5.7 and 82.0$\pm$5.1%) than 22 and 24 hr maturation group. The proportion of BL formed on day 7 and 8 was significantly higher(P<0.05) in 18 hr maturation group(85%) than in 24 hr maturation group(55%). There was a significant difference(P<0.05) in inner cell mass, trophectoderm and total cell number between day 7 BL produced by in-vivo and IVM 18 hr and day 8 BL produced by IVM 18 hr and 24 hr. Pregnancy rates are also significantly higher(P<0.05) in in-vivo(56.3%) and IVM 18 hr day 7(50.0%) group than day 8 treatment groups(18 hr: 16.7%, 24 hr: 10.5%). These results suggest that KNC oocytes achieve developmental competency within 20 hr of IVM, and "short" IVM (18 hr) is more effective than "long" IVM(24 hr) in embryo development rates, BL cell numbers and pregnancy rates.

• 한국가축번식학회지
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• 제17권4호
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• pp.331-337
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• 1994

처녀발생은 난자의 세포질성숙을 투명대경화나 체외수정에 있어 난자 외적요소의 문제점을 배제하고 측정할 수 있는 지표이다. 본 실험에서는 체외성숙시간에 따른 소 난자의 처녀발생활성을 조사하였다. 도살장 난소로부터 회수한 미성숙난포란을 15% 소 태아혈청이 첨가된 TCM 199에서 6시간 간격으로 24~48시간까지 성숙시킨 후 7% ethanol로 7분간 활성화시켰다. 핵성숙과 세포질성숙은 rapid staining에 의해 핵형태와 전핵의 형성 유무로 판정하였다 핵성숙율은 24~48시간 사이 각각 81, 89, 72, 60 및 60%로 체외성숙 36시간에 성숙율이 최고였으나, 반면 감수분열 중기 II 염색체이상은 36시간부터 증가(0~30%)하였다. 에탄올처리에 의한 전핵형성율은 체외성숙 24~48시간에 각각 67, 68, 73, 84 및 87%였고, 그 중 이배체율은 각각 4, 5, 10, 16 및 20%로 성숙시간이 증가함에 따라 증가하였다. 위 실험의 결과 난자의 체외성숙 연장에 따라 전핵형성과 이배체수가 증가되는 것으로 나타났으며, 정상적인 핵성숙에 비해 세포질성숙은 더 많은 성숙시간이 필요한 것으로 나타났다. 이러한 결과들은 소 초기배 체외생산시와 핵치환용 핵수용란 생산시 적정 성숙시간 결정에 유용하게 이용될 수 있을 것이다.