• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.496-500
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• 2007

Holstein cow ovaries obtained at a slaughterhouse were used to study the influence of the oocyte collection methods (slicing, puncture, aspiration I and II) on recovery efficiency and subsequent in vitro maturation and embryonic development competence of immature oocytes recovered. In the slicing method, the whole ovarian was chopped into small pieces with a surgical blade. In the puncture method, the whole ovarian surface was punctured by 18-g needle. In other 2 aspiration methods, collected oocytes by aspirating from the visible follicles using an 18-g needle attached to a 5 ml syringe (aspiration I) or using a constant negetive pressure (-80 mmHg) with a vacuum pump (aspiration II). The oocytes were classified into 4 classes on the basis of the morphology of cumulus cells and cytoplasmic appearance of oocyte. Slicing ($9.6{\pm}0.4$) and puncture ($9.7{\pm}0.4$)yielded a larger number of oocytes per ovary than other two aspiration methods (aspiration I and II were $5.8{\pm}0.3$and $5.6{\pm}0.4$, respectively) (p<0.05). The number of the highest quality oocytes (grade A) per ovary was significantly higher in slicing ($4.2{\pm}0.2$) and puncture ($4.6{\pm}0.1$) methods than in other methods (aspiration I and II were $1.2{\pm}0.2$ and $1.4{\pm}0.2$, respectively) (p<0.05). The rate of nuclear maturation of the highest and higher quality oocytes (grade A and grade B, respectively) was not affected by the oocytes collection methods. The oocytes collection methods also did not influence subsequent embryonic developmental competence after in vitro fertilization with M II stage oocytes. It is concluded that slicing and puncture methods of the ovaries can be used as an alternative techniques to aspiration by the syringe or vacuum pump.

• Molecules and Cells
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• v.23 no.1
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• pp.49-56
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• 2007

One of the goals of stem cell technology is to control the differentiation of human embryonic stem cells (hESCs), thereby generating large numbers of specific cell types for many applications including cell replacement therapy. Although individual hESC lines resemble each other in expressing pluripotency markers and telomerase activity, it is not clear whether they are equivalent in their developmental potential in vitro. We compared the developmental competence of three hESC lines (HSF6, Miz-hES4, and Miz-hES6). All three generated the three embryonic germ layers, extraembryonic tissues, and primordial germ cells during embryoid body (EB) formation. However, HSF6 and Miz-hES6 readily formed neuroectoderm, whereas Miz-hES4 differentiated preferentially into mesoderm and endoderm. Upon terminal differentiation, HSF6 and Miz-hES6 produced mainly neuronal cells whereas Miz-hES4 mainly formed mesendodermal derivatives, including endothelial cells, leukocyte progenitors, hepatocytes, and pancreatic cells. Our observations suggest that independently-derived hESCs may differ in their developmental potential.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.179-187
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• 2010

Embryonic compaction is essential for normal preimplantation development in mammals. The present study was to investigate the effects of compaction patterns on developmental competence of pig embryos. The proportion of blastocyst formation derived from compacted morula was higher than those of compacting and pre-compacting morula (P<0.01). Nuclei numbers of inner cell mass (ICM), trophectoderm (TE), and total of blastocysts derived from compacted group were also superior to those of compacting and pre-compacting groups (P<0.05). Then, compaction patterns, developmental ability and structural integrity were compared between mono- and poly-spermic embryos. The rate of compacted morula in mono-spermic embryos was higher than that of poly-spermic embryos (P<0.05). Especially, the rate of blastocyst formation derived from compacted embryos in mono-spermic embryo group was higher than that of poly-spermic embryo group (P<0.05), although no difference was detected between the two groups in the structural integrity. Finally, we confirmed that beta-catenin was differentially expressed according to compaction patterns in morula and blastocyst stage embryos. In conclusion, our results suggest that the compaction patterns during preimplantation development play a direct role in developmetal competence and quality of pig embryos.

• Korean Journal of Agricultural Science
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• v.43 no.1
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• pp.52-60
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• 2016

In animal reproduction, the quality of oocytes and embryos has been evaluated by the expression of specific molecules. Follistatin (FST), which was isolated from follicular fluid, binds and bio-neutralizes the TGF-${\beta}$ superfamily members. Previous studies using the bovine model showed FST could be an important molecular determinant of embryo developmental competence. However, the effect of FST treatment on porcine embryo developmental competence has not been established. In this study, the effect of exogenous FST on porcine embryo developmental competence was investigated during in vitro culture. FST (10 ng/ml) treatment induced a significant decrease in the rate of cell arrest at the 4-cell stage. The expression levels of DNA-methyltransferase 1 (DNMT1), histone deacetylase 1 (HDAC1), and histone deacetylase 2 (HDAC2) were decreased in 4-cell stage embryos. FST treatment also resulted in significant improvements in developmental competence of embryos in terms of blastocyst formation rate and OCT-4 mRNA levels, the latter being related to pluripotency. In conclusion, during in vitro culture, FST treatment significantly ameliorated 4-cell block during embryonic development and improved embryo developmental competence. Therefore, FST treatment may potentially have a functional role in porcine embryogenesis that is broadly applicable to enhance in vitro embryo development.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.4
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• pp.347-356
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• 2020

Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.

• 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.

• Korean Journal of Veterinary Research
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• v.63 no.1
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• pp.3.1-3.9
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• 2023

The efficiency of somatic cell nuclear transfer (NT) in pigs is low and requires enhancement. We identified the most efficient method for zona pellucida (ZP) removal and blastomere aggregation in pigs and investigated whether the aggregation of NT and parthenogenetic activation (PA) of blastomeres could reduce embryonic apoptosis and improve the quality of NT-derived embryos by investigating. Embryonic developmental competence after ZP removal using acid Tyrode's solution or protease (pronase E). The embryonic developmental potential of NT-derived blastomeres was also investigated using well-of-the-well or phytohemagglutinin-L. We analyzed apoptosis in aggregate-derived blastocysts. The aggregation rate of protease-treated embryos was lower than that of Tyrode's solution-treated embryos (69.2% vs. 88.3%). No significant difference was observed between phytohemagglutinin-L and well-of-the-well (35.7%-38.5%). However, 2P1N showed a higher number of blastocysts compared to 3N (73.8% vs. 24.3%) and an increased blastocyst diameter compared to the control and 1P2N (274 ㎛ vs. 230-234 ㎛). In blastomeres aggregated using phytohemagglutinin-L, the apoptotic cell ratio was significantly higher in 1P2N and 3N than in 3P (5.91%-6.46% vs. 2.94%, respectively). Our results indicate that aggregation of one NT embryo with two PA embryos improved the rate of blastocysts with increased blastocyst diameter.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.2-11
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• 2020

Assisted reproductive technologies (ART) merely depend on improving the oocyte maturation and their developmental competence to produce good quality embryos. Oocyte maturation passes through long and complex molecular steps starts from the early embryonic life and ends with sperm fertilization. Oocyte developmental competence can be attained by improving the nuclear and cytoplasmic mechanisms together with some epigenetic maturation. In this review, we highlight the cornerstones of oocyte maturation on both nuclear and cytoplasmic levels. Interfering or supporting these molecular mechanisms would help in the development of novel regulating agents for reproductive performance of humans and livestock species.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.86-92
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• 2019

The aim of this study was to investigate effects of hyaluronidase during IVM on oocyte maturation, oxidative stress status, expression of cumulus expansion-related (PTX, pentraxin; GJA1, gap junction protein alpha 1; PTGS2, prostaglandin-endoperoxide synthase 2) and fatty acid metabolism-related (FADS1, delta-6 desaturase; FADS2, delta-5 desaturase; PPARα, peroxisome proliferator-activated receptor-alpha) mRNA, and embryonic development of porcine oocytes. The cumulus-oocyte complexes (COCs) were incubated with 0.1 mg/mL hyaluronidase for 44 h. Cumulus expansion was measured at 22 h after maturation. At 44 h after maturation, nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured. Gene expression in cumulus cells was analyzed using real time PCR. The cleavage rate and blastocyst formation were evaluated at Day 2 and 7 after insemination. In results, expansion of cumulus cells was suppressed by treatment of hyaluronidase at 22 h after maturation. Intracellular GSH level was reduced by hyaluronidase treatment (p < 0.05). On the other hand, hyaluronidase increased ROS levels in oocytes (p < 0.05). Only PTGS2 mRNA was enhanced in COCs by hyaluronidase (p < 0.05). Population of oocytes reached at metaphase II stage was higher in control group than hyaluronidase treated group (p < 0.05). Both of cleavage rate and blastocyst formation were higher in control group than hyaluronidase group (p < 0.05). Our present results showed that developmental competence of porcine oocytes could be reduce by hyaluronidase via inducing oxidative stress during maturation process and it might be associated with prostaglandin synthesis. Therefore, we suggest that suppression of cumulus expansion of COCs could induce oxidative stress and decrease nuclear maturation via reduction of GSH synthesis and it caused to decrease developmental competence of mammalian oocytes.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.307-311
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of several cells. In our previous study, inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the pig embryonic and primary cells was reported. However, its role during early bovine embryonic development is not sufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on early bovine embryonic development. We also investigated several indicators of developmental potential, including structural integrity, gene expression (apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Bovine embryos were cultured in the CR1-aa medium with or without 17-AAG for 7 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG ($33.1{\pm}9.6$ vs $21.7{\pm}8.3%$). The structural integrity of the blastocysts was examined by differential staining. Blastocysts from the dbcAMP-treated group had higher numbers of ICM, TE, and total cells than those from the untreated group. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (11.2 vs 3.9, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation bovine blastocysts. The mRNA expression of the pro-apoptotic gene (Bax) increased in 17-AAG treated group, whereas expression of the antiapoptotic gene (Bcl-XL) decreased. In conclusion, Hsp90 also appears to play a direct role in bovine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with apoptosis-related genes expression in developing bovine embryos.