• 한국수정란이식학회지
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• 제19권3호
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• pp.219-227
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• 2004

본 연구는 체외 성숙액인 TCM-199 배지를 기초로 무혈청첨가물인 PVA, PVP 및 pFF의 한정배지를 이용하여 돼지 미성숙난자의 체외성숙, 수정 및 배양 후 난자의 수정율과 배발달에 미치는 영향과 나아가 BSA 대체물로서의 이용 가능성을 알아보았다. 1. 무혈청 첨가물을 이용하여 난포란의 체외 성숙을 유기한 결과 PVA, PVP, pFF, BSA의 전체 분할율은 각각 82.4%, 78.6%, 89.4%, 90.0%로 나타났으며, GV, MI-MII율은 PVA 첨가시 각각 15.1%, 84.9%, PVP는 각각 26.5%, 73.5%, pFF는 각각 11.8%, 88.2%, BSA는 각각 11.1%, 88.9%로 PVA 혹은 pFF 첨가시에는 모두 BSA와 유사한 결과를 보였으나 PVP와는 유의적인 차이를 나타내었다 (P<0.05). 2. 체외 성숙된 난자를 수정시킨 후의 배발달율을 확인한 결과 전체 난할율은 PVA가 73%, PVP는 64.1% , pFF가 77.2%, BSA가 73%로 PVA와 pFF는 BSA와 유사하게 나타났으나, PVP는 그 발달율이 다른 처리군 들과 비교하여 유의적(P<0.05)으로 낮은 결과를 보였다. 3. 각 처리구간의 morulae와 blastocyst의 합을 비교한 결과 체외성숙 첨가물 중 PVA와 pFF는 각각 63%, 69%로 BSA(65%)와 유사한 결과를 나타내었으나 PVP는 54%로 유의적으로 낮은 결과를 나타내었다(P<0.05). 4. 전체 성숙율과 수정율을 비교해 본 결과 성숙 율은 PVA, pFF, BSA가 82.4%, 89.4%, 90.0%인 반면 PVP는 72.4%로 유의적으로(P<0.05) 낮은 결과를 보였고, 수정율은 pFF, BSA가 각각 87.1%, 89.1%로 PVA, PVP의 78.0%, 70.6%에 비해 각각 유의적(P<0.05)으로 높았다. 이상의 연구결과 돼지 난자의 체외성숙 및 배양 배지에 있어 PVA, pFF 첨가는 BSA 대체물로서 이용이 가능하나 PVP는 그 이용에 제한이 따를 것으로 판단된다.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.7-12
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• 2012

DNA methyltransferase 1 (Dnmt1) gene contains three different isoform transcripts, Dnmt1s, Dnmt1o, and Dnmt1p, are produced by alternative usage of multiple first exons. Dnmt1o is specific to oocytes and preimplantation embryos, whereas Dnmt1s is expressed in somatic cells. Here we determined that porcine Dnmt1o gene had differentially methylated regions (DMRs) in 5'-flanking region, while those were not found in the Dnmt1s promoter region. The methylation patterns of the porcine Dnmt1o/Dnmt1s DMRs were investigated using bisulfite sequencing and pyrosequencing analysis through all preimplantation stages from one cell to blastocyst stage in in vivo or somatic cell nuclear transfer (SCNT). The Dnmt1o DMRs contained 8 CpG sites, which located in -640 bp to -30 bp upstream region from transcription start site of the Dnmt1o gene. The methylation status of 5 CpGs within the Dnmt1o DMRs were distinctively different at each stage from one-cell to blastocyst stage in the $in$ $vivo$ or SCNT, respectively. 55.62% methylation degree of the Dnmt1o DMRs in the $in$ $vivo$ was increased up to 84.38% in the SCNT embryo, moreover, $de$ $novo$ methylation and demethylation occurred during development of porcine embryos from the one-cell stage to the blastocyst stage. However, the DNA methylation states at CpG sites in the Dnmt1s promoter regions were hypomethylated, and dramatically not changed through one-cell to blastocyst stage in the $in$ $vivo$ or SCNT embryos. In the present study, we demonstrated that the DMRs in the promoter region of the porcine Dnmt1o was well conserved, contributing to establishment and maintenance of genome-wide patterns of DNA methylation in early embryonic development.

• 한국수정란이식학회지
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• 제31권1호
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• pp.33-38
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• 2016

In this study, to improve the in vitro development of various cells including cloned embryos, the effects that isoproterenol and melatonin have on in vitro development of porcine parthenogenetic oocytes were investigated. Parthenogenetic activation was induced with electrical stimulation, BSA and 6-DMAP treatment. $10^{-7}M$ of melatonin and isoproterenol ($10^{-10}$, $10^{-12}$ and $10^{-14}M$) were supplemented for in vitro maturation (IVM) and in vitro culture (IVC) medium, with different concentrations. When isoproterenol and melatonin were supplemented in IVM medium with different concentrations, there was no significant (P<0.05) difference of maturation rate in the treatment groups as well as in that of only melatonin. As isoproterenol and melatonin were supplemented in IVM medium with different concentrations, blastocyst rates of isoproterenol $10^{-12}M$ treatment group (37.1%) were significantly (P<0.05) higher than control group (26.0%). Isoproterenol and melatonin were supplemented in IVC medium with different concentrations, then the cleavage rate of $10^{-12}M$ isoproterenol treatment group (82.2%) was significantly (P<0.05) higher than the group that melatonin was only supplemented (70.9%). There was no difference of blastocyst rate between the treatment groups. When isoproterenol and melatonin were supplemented for IVM+IVC medium with different concentrations, the cleavage rate of $10^{-12}M$ isoproterenol treatment group (92.5%) was significantly (P<0.05) higher than the control group (82.8%) and the group that melatonin was only treated (81.6%). The blastocyst rate of $10^{-12}M$ as 45.6% was significantly (P<0.05) higher than control group (25.2%) and melatonin treatment group (31.2%). The cell number of blastocyst in $10^{-12}M$ isoproterenol treatment group $35.5{\pm}3.4$ was significantly (P<0.05) highest. The results of this study showed that the development rate of IVC when both isoproterenol and melatonin were supplemented was higher than when melatonin was only supplemented. Therefore, it is concluded that isoproterenol is rather effective in the activation of melatonin. $10^{-7}M$ melatonin and $10^{-12}M$ isoproterenol were considered suitable concentration.

• 한국수정란이식학회지
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• 제32권1호
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• pp.25-31
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• 2017

This study was conducted to investigate the effect of activation method on the endoplasmic reticulum (ER) stress induction, apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus (ES) (E), 2) $ES+10{\mu}M$ Ca-ionophore (A23187) treatment (EC), 3) ES+2 mM 6-dimethylaminopurine (6-DMAP) treatment (ED), or 4) ES+A23187 and 6-DMAP treatments (ECD). Parthenogenetic embryos were sampled to analyze x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptosis genes at 3 h after ES and the 1-cell and blastocyst stages. In the EC group, the band intensity of spliced Xbp1 (Xbp1s) mRNA was higher than those of the other groups at the 3 h and 1-cell stage, and higher than that of the E group at the blastocyst stage. Four ER stress-associated genes were expressed at the highest level in the EC group and weakly expressed in the ED group at 3 h after activation. However, most of the genes were highly expressed at the 1-cell and blastocyst stages with some variation in the EC and ECD groups. Expression of Bcl-2-associated X protein (Bax) and caspase-3 mRNA was significantly higher in the EC group than in the other groups at all development stages. The developmental rates to the blastocyst stage were higher in the ED and ECD groups than in the E and EC groups. These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by the activation method and subsequently lead to the apoptosis of embryos.

• 한국수정란이식학회지
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• 제32권3호
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• pp.95-104
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• 2017

This study was conducted to establish the optimal chemical post-activation conditions in porcine embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) using 4 different chemical compositions (cytochalasin B (CB), cyclohexamide (CHX), demecolcine (DC), 6-dimethylaminopurine (DMAP). Porcine embryos were produced by PA and SCNT and then, cultured for post-activation with CB ($7.5{\mu}g/mL$), CB ($7.5{\mu}g/mL$) + CHX ($10{\mu}g/mL$), CB ($7.5{\mu}g/mL$) +DC ($0.4{\mu}g/mL$), and CB ($7.5{\mu}g/mL$) + DMAP (2 mM). In PA embryonic development, cleavage rates have been significantly higher in CB group (94.7%) and CB+DMAP group (94.1%) than that of CB+CHX and CB+DC group (88.1 and 84.3%, respectively). There have been no significant differences in blastocyst formation rates among the four groups. In cell number of blastocyst was shown in CB group (42.3%) significantly higher than CB+CHX and CB+DC group (40.6 and 40.6%, respectively). In SCNT embryonic development, CB+DMAP group (89.7%) significant differences were found on embryo cleavage rates when compared with other three groups. Blastocyst formation rates in CB+DMAP group (26.9%) were significantly higher when compared with CB, CB+CHX, and CB+DC groups (25.5, 20.2, and 22.1%, respectively). In blastocyst cell number, CB+DMAP group (41.4%) was found higher significant difference compared with other three groups. Additionally, we have investigated survivin expression in early development stages of porcine SCNT embryos for more confirmation. Our results establish that CB group and CB+DMAP group for 4 h during post-activation improves pre-implantation improvement of PA and SCNT embryos.

• 한국수정란이식학회지
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• 제33권4호
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• pp.211-220
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• 2018

Nitric oxide (NO) has an important role in oocyte maturation and embryonic development in mammals. This study examined the effect of exogenous NO donor S-nitroso-N-acetylpenicillamine (SNAP) in a maturation medium on meiotic progression and embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. When oocytes were exposed to $0.1{\mu}M$ SNAP for first 22 h of in vitro maturation (IVM) in Experiment 1, SNAP significantly improved blastocyst development in both defined and standard follicular fluid-supplemented media compared to untreated control (48.4 vs. 31.7-42.5%). SNAP treatment significantly arrested meiotic progression of oocytes at the germinal vesicle stage at 11 h of IVM (61.2 vs. 38.7%). However, there was no effect on meiotic progression at 22 h of IVM (Experiment 2). In Experiment 3, when oocytes were treated with SNAP at 0.001, 0.1 and $10{\mu}M$ during the first 22 h of IVM to determine a suitable concentration, $0.1{\mu}M$ SNAP (54.2%) exhibited a higher blastocyst formation than 0 and $10{\mu}M$ SNAP (36.6 and 36.6%, respectively). Time-dependent effect of SNAP treatment was evaluated in Experiment 4. It was observed that SNAP treatment for the first 22 h of IVM significantly increased blastocyst formation compared to no treatment (57.1% vs. 46.2%). Antioxidant effect of SNAP was compared with that of cysteine. SNAP treatment significantly improved embryonic development to the blastocyst stage (49.1-51.5% vs. 34.4-37.5%) irrespective of the presence or absence of cysteine (Experiment 5). Moreover, SNAP significantly increased glutathione (GSH) content and inversely decreased the reactive oxygen species (ROS) level and mitochondrial oxidative activity in IVM oocytes. SNAP treatment during IVM showed a stimulating effect on in vitro development of SCNT embryos (Experiment 7). These results demonstrates that SNAP improves developmental competence of PA and SCNT embryos probably by maintaining the redox homeostasis through increasing GSH content and mitochondrial quality and decreasing ROS in IVM oocytes.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.68-68
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• 2001

Blastocyst formation, consisting of the inner cell mass (ICM) and trophectoderm (TE), is the first differentiation process during embryonic development in mammals. It has been hypothesized that the proportion of ICM to TE in the blastocyst may be crucial for subsequent developmental competence of early embryos, which it may be expressed as a sensitive indicator for evaluating in vitro systems. In this study ICM/total cell ratio of nuclear transfer (NT) embryos was compared with IVF-derived and in vivo embryos. Somatic cell nuclei obtained from a fetus at Day 40 of gestation were transferred into the enucleated oocyte and then cultured in NCSU 23 medium for 6 days as previously described (Koo et al., Biol. Reprod. 2000; 63:986-992). ICM and TE cells of blastocysts were determined by using a differential staining method (Han et al., Biol. Reprod. 1999; 60:1110-1113). Development rate (9.8$\pm$2.5%, 23/225) to the blastocyst stage of NT embryos was lower than IVF embryos (23.8$\pm$2.7%, 53/223). Thus, a difference was detected in the in vitro developmental rate to blastocyst stage between NT and IVF-derived embryos (P<0.05). In the next experiment, we investigated ICM and TE nuclei to assess the quality of blastocysts that produced by NT, IVF and in vivo, respectively. NT blastocysts (27.6$\pm$8.3) showed a smaller total cell number than IVF-derived (42.6$\pm$17.4) and in vivo embryos (283.9$\pm$103.5) (P<0.05). Ratios of ICM/total cells in NT, IVF and in vivo blastocysts were 15.1$\pm$ 18.6% (n=56), 12.3$\pm$9.2% (n=57) and 30.4$\pm$6.8% (n=40), respectively. Individual blastocysts for the ratio of ICM/total cells were assigned to 3 groups (I; <20%, II; 20 to 40% and III;>40%). As the results, most in vivo blastocysts (97.5%, 39/40) were distributed into group II while most NT (78.6%, 44/56) and IVF-derived blastocysts (82.5%, 47/57) were allocated to group I. Thus, our data show that NT or IVF-derived embryos have aberrant morphology during early development in vitro systems, suggesting that these anomalies may result in developmental failures of the NT embryos to term.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 춘계학술세미나 및 워크숍
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• pp.19-25
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• 2002

Researches on manipulation pluripotent stem cells derived from blastocysts or promordial germ cells (PGCs) have a great advantages for developing innovative technologies in various fields of life science including medicine, pharmaceutics, and biotechnology. Since the first isolation in the mouse embryos, stem cells or stem cell-like colonies have been continuously established in the mouse of different strains, cattle, pig, rabbit, and human. In the animal species, stem cell biology is important for developing transgenic technology including disease model animal and bioreactor production. ES cell can be isolated from the inner cell mass of blastocysts by either mechanical operation or immunosurgery. So, mass production of blastocyst is a prerequisite factor for successful undertaking ES cell manipulation. In the case of animal ES cell research, various protocol of gamete biotechnology can be applied for improving the efficiency of stem cell research. Somatic cell nuclear transfer technique can be applied to researches on animal ES cells, since it is powerful tool for producing clone embryos containing genes of interest. In this presentation, a brief review was made for explaining how somatic cell nuclear transfer technology could contribute to improving stem cell manipulation technology.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.966-975
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• 1999

Technologies on preimplantation porcine embryos have been developed quickly and significantly. Successful development of systems for culture of porcine zygotes to the blastocyst stage has made it possible to utilize follicular oocytes for in vitro production of embryos and thus stimulated research on various embryo technologies. Recent technological development of embryo cryopreservation, separation of X- and Y-bearing spermatozoa and non-surgical embryo transfer has also made it easy to utilize in vivo- and in vitro-produced embryos for artificial manipulation to produce clones and transgenic pigs. Further progress in overcoming various problems associated with each embryo technology will result in acceptable efficiency to utilize porcine embryos with a high or increased quality. Combining these technologies will accelerate further expansion of the swine industry not only for meat production but also for the production of therapeutic recombinant proteins and xonografts.

• Reproductive and Developmental Biology
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• 제36권4호
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• pp.237-241
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• 2012

Embryonic genome activation (EGA) is the first major transition that occurs after fertilization, and entails a dramatic reprogramming of gene expression that is essential for continued development. Although it has been suggested that EGA in porcine embryos starts at the four-cell stage, recent evidence indicates that EGA may commence even earlier; however, the molecular details of EGA remain incompletely understood. The RNA polymerase II of eukaryotes transcribes mRNAs and most small nuclear RNAs. The largest subunit of RNA polymerase II can become phosphorylated in the C-terminal domain. The unphosphorylated form of the RNA polymerase II largest subunit C-terminal domain (IIa) plays a role in initiation of transcription, and the phosphorylated form (IIo) is required for transcriptional elongation and mRNA splicing. In the present study, we explored the nuclear translocation, nuclear localization, and phosphorylation dynamics of the RNA polymerase II C-terminal domain in immature pig oocytes, mature oocytes, two-, four-, and eight-cell embryos, and the morula and blastocyst. To this end, we used antibodies specific for the IIa and IIo forms of RNA polymerase II to stain the proteins. Unphosphorylated RNA polymerase II stained strongly in the nuclei of germinal vesicle oocytes, whereas the phosphorylated form of the enzyme was confined to the chromatin of prophase I oocytes. After fertilization, both unphosphorylated and phosphorylated RNA polymerase II began to accumulate in the nuclei of early stage one-cell embryos, and this pattern was maintained through to the blastocyst stage. The results suggest that both porcine oocytes and early embryos are transcriptionally competent, and that transcription of embryonic genes during the first three cell cycles parallels expression of phosphorylated RNA polymerase II.