• Development and Reproduction
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• v.21 no.2
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• pp.131-138
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• 2017

This study was conducted to investigate stimulatory effect of epidermal growth factor (EGF) on nuclear maturation and the expression level of EGF-receptor (EGFR), GM-130 (a marker of Golgi apparatus), transport protein Sec61 subunit beta ($Sec61{\beta}$), and coatomer protein complex subunit gamma 2 (COPG2) in porcine oocytes. The cumulus-oocyte complexes were collected from follicle with 3-6 mm in diameter. They were incubated in medium with/without EGF for 22 h (IVM I) and subsequently incubated hormone-free medium with/without EGF for 22 h (IVM II). Nuclear maturation state was checked by aceto-orcein stain. Protein expression of EGFR, GM-130, $Sec61{\beta}$, and COPG2 were measured by immunofluorescence. In results, nuclear maturation of oocytes in EGF non-treated oocytes were significantly lower than EGF-treated groups at IVM I or IVM II stage (P<0.05), whereas maturational rate in EGF treatment groups at both of IVM stage was higher in among the all treatment groups (P<0.05). EGFR, GM-130, $Sec61{\beta}$ and COPG2 were expressed in the cytoplasm of oocytes. Especially, GM-130 and EGFR were strongly expressed, but $Sec61{\beta}$ and COPG2 were weakly expressed in cortical area of cytoplasm. The protein level of GM-130, $Sec61{\beta}$, and COPG2 were significantly higher in the EGF-treated groups (P<0.05). However EGFR was no difference between non EGF-treated groups and control. In conclusion, EGF plays an important role in the systems for oocyte maturation with endoplasmic reticulum and Golgi apparatus. In addition, the protein levels of $Sec61{\beta}$ and COPG2 could be changed by EGF in the porcine oocytes during maturation.

• Journal of Embryo Transfer
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• v.24 no.2
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• pp.97-104
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• 2009

The objective of this study was to examine the effect of macromolecule in a maturation medium on nuclear maturation, intracellular glutathione (GSH) level of oocytes, and embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in pigs. Immature pig oocytes were cultured in maturation medium that was supplemented with each polyvinyl alcohol (PVA), pig follicular fluid (pFF) or newborn calf serum (NBCS) during the first 22 h and the second 22 h. Oocyte maturation was not influenced by the source of macromolecules during in vitro maturation (IVM). Embryo cleavage and cell number in blastocyst after PA was altered by the source of macromolecule but no difference was observed in blastocyst formation among treatments. Oocytes matured in PVA-PVA medium showed lower rates of oocyte-cell fusion (70.4% vs. 77${\sim}$82%) and embryo cleavage (75% vs. 86${\sim}$90%) after SCNT than those matured in other media but blastocyst formation was not altered (13${\sim}$27%) by different macromolecules. pFF added to IVM medium significantly increased the intracellular GSH level of oocytes compared to PVA and NBCS, particularly when pFF was supplemented during the first 22 h of IVM. Our results demonstrate that source of macromolecule in IVM medium influences developmental competence of oocytes after PA and SCNT, and that pFF supplementation during the early period (first 22 h) of IVM increases intracellular GSH level of oocytes.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.235-243
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• 2007

Our goal was to examine the effects of early denudation on the enucleation efficiency and developmental competence of embryos following somatic cell nuclear transfer (SCNT) and parthenogenetic activation (PA). Oocytes were denuded following 30 h of in vitro maturation (IVM) and then cultured with (D+) or without (D-) their detached cumulus cells for additional $10{\sim}14$ h. Control oocytes were denuded after $40{\sim}44$ h of IVM. The size of the perivitelline space was larger at 40 h of IVM ($11.7{\sim}11.8{\mu}m$) than at 30 h ($8.9{\mu}m;$ p<0.01). The distances between the metaphase II (M II) plates and the polar bodies (PBs) were shorter in D+ ($19.4{\mu}m$) and D- oocytes ($18.9{\mu}m$) than in control oocytes ($25.5{\mu}m;$ p<0.01). Enucleation rates following blind aspiration at 40 h of IVM were higher (p<0.01) in D+ (92%) and D- oocytes (93%) compared to controls (82%). Early denudation did not affect oocyte maturation or the in vitro development of SCNT and PA embryos. When SCNT embryos from D+ oocytes were transferred to four gilts, pregnancy was established in two pigs, and one of them farrowed three live piglets. In conclusion, early denudation of oocytes at 30 h of IVM could improve the enucleation efficiency by maintaining the M II plate and the PB within close proximity and support the in vivo development of SCNT embryos to term.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.31.1-31.13
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• 2022

Background: Compared to medium containing 108 mM sodium chloride (NaCl), in vitro maturation (IVM) using a simple medium with reduced (61.6 mM) NaCl increases the cytoplasmic maturation and embryonic development of pig oocytes. Objectives: This study determines the effect of a complex medium containing reduced NaCl on the IVM and embryonic development of pig oocytes. Methods: Pig oocytes were matured in Minimum Essential Medium Eagle-alpha modification (αMEM) supplemented with 61.6 (61αMEM) or 108 (108αMEM) mM NaCl, and containing polyvinyl alcohol (PVA) (αMEMP) or pig follicular fluid (PFF) (αMEMF). Medium-199 (M199) served as the control for conventional IVM. Cumulus cell expansion, nuclear maturation, intra-oocyte glutathione (GSH) contents, size of perivitelline space (PVS), and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) were evaluated after IVM. Results: Regardless of PVA or PFF supplementation, oocytes matured in 61αMEM showed increased intra-oocyte GSH contents and width of PVS (p < 0.05), as well as increased blastocyst formation (p < 0.05) after PA and SCNT, as compared to oocytes matured in 108αMEMP and M199. Under conditions of PFF-enriched αMEM, SCNT oocytes matured in 61αMEMF showed higher blastocyst formation (p < 0.05), compared to maturation in 108αMEMF and M199, whereas PA cultured oocytes showed no significant difference. Conclusions: IVM in αMEM supplemented with reduced NaCl (61.6 mM) enhances the embryonic developmental competence subsequent to PA and SCNT, which attributes toward improved oocyte maturation.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.201-201
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• 2004

In this study we examined whether vitrified Hanwoo (Korean cattle) IVM/IVF/IVC blastocysts can survive in vitro/in vivo by a quick one-step dilution method and these embryos result in live births. Blastocysts produced in vitro were vitrified by serial exposure to glycerol (G) and/or ethylene glycol (EG) mixtures of 10% (v/v) G for 5 min, 10% G plus 20% EG (v/v) for 5 min, and 25% G plus 25% EG (v/v) for 30 see. (omitted)

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.429-440
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• 1996

In order to know morphological changes on the female genital organs by Ivermectin(IVM) administration, the histopathological observation was carried out in the organs of rat and mouse treated with the overdose of IVM. In the microscopical findings of the uterus, there were many mitotic figures, epithelial hyperplasia and papillary foldings in the endometrial surface. The increased prevalance of uterine glands, uterine epithelia and glands hyperplasia were markedly presented on diverse patterns adenoma-like structure and single nodular or multiple polyp-like adenoma. In ovary, primary and mature follicles were decreased in number, and hypoplasia of ovarian follicles, atretic follicles, follicular cysts and ovarian atropy were observed. It was considered that IVM administration resulted in follicular hypoplasia and atropy of ovary, and hyperplasia of uterine gland and endometrial surface epithelium might be transformed to neoplasia of glandular structures.

• Communications for Statistical Applications and Methods
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• v.10 no.1
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• pp.225-232
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• 2003

The support vector machine (SVM) is becoming increasingly popular in classification. The import vector machine (IVM) has been introduced for its advantages over SMV. This paper tries to improve the IVM. The proposed method, which is referred to as the polychotomous machine (PM), uses the Newton-Raphson method to find estimates of coefficients, and the Rao and Wald tests, respectively, for addition and deletion of import points. Because the PM basically follows the same addition step and adopts the deletion step, it uses, typically, less import vectors than the IVM without loosing accuracy. Simulated and real data sets are used to illustrate the performance of the proposed method.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.183-188
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• 2021

In vitro maturation (IVM) of oocytes is the procedure where the immature oocytes are cultivated in a laboratory until they are mature. Since IVM oocytes generally have low developmental competence as compared to those matured in vivo, development of an optimal IVM culture system by fine-tuning culture conditions is crucial to maintain high quality. In-depth knowledge and a deep understanding of the in vivo physiology of oocyte maturation are pre-requisites to accomplish this. Within ovarian follicles, various signaling pathways that drive oocyte development and maturation regulate interaction between oocytes and surrounding somatic cells. This review discusses the sonic hedgehog (SHH) signaling pathway, which has been demonstrated to be intimately involved in folliculogenesis and oocyte maturation. Advances in elucidating the role of the SHH signaling pathway in oocyte maturation will aid attempts to improve the current inferior in vitro oocyte maturation system.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.31-36
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• 2005

The purpose of this study was an improvement of efficiency and quality in the production of Korean Native Cow embryos. We investigated effects of concentration of ammonia in in vitro maturation (IVM) medium. In addition, we examined effects of addition or exchange of IVM medium on subsequent development and the cell numbers of blastocysts. The concentrations of ammonia in IVM medium was significantly increased by the increasement of IVM duration (p<0.05). The development rates to the 2 cell-, 8 cell- and blastocyst-stage embryos with the addition of IVM medium were similar among treatment groups. The number of inner cell mass (ICM) cells and the total cell number (TCN) of blastocysts were not differ among treatment groups, whereas the trophectoderm (TE) cell number was significantly lower in the group of 4.5 h addition. The ICM/TCN ratio was significantly higher in the group of 4.5 h addition than in the group of control and 9 h addition. The development rate to the 2-cell embryo with the exchange of IVM medium was significantly higher in the group of 4.5 h exchange and 9 h exchange than in control. The development rate to the blastocyst stage was the highest in the group of 9 h exchange. The number of ICM and ICM/TCN ratio were significantly higher in the group of 9 h exchange than the other groups. The numbers of TE and TCN was similar among treatment groups.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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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.