• Korean Journal of Animal Reproduction
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• v.27 no.2
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• pp.103-113
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• 2003

This study was conducted to investigate the optimal condition for produce of large quantity recipient oocytes on porcine cloned embryos. In order to determined the optimum concentration and exposure time of ethanol, $Ca^{2+}$-ionophore, 6-DMAP and cycloheximide, in vitro matured oocytes were activated in TCM-199 containing various chemicals and 15% FBS. The activated oocytes were cultured in Whitten's medium containing 10% FBS at 5% $CO_2$. 1. When the porcine oocytes were activated with the ethanol, the best pronucleus formation, cleavage, and in vitro development rate were obtained in the 10% for 10 minutes, which was significantly higher than all of the other treatment(53.4%, 51.6% and 39.9%, respectively). 2. When the porcine oocytes were activated with the $Ca^{2+}$-ionophore, the pronucleus furmation, cleavage, and in vitro development rate were found significantly higher in the 25$\mu$M fur 2min. treatment than those of other concentration and exposure time(59.7%, 62.2% and 43.9%, respectively). 3. When the porcine oocytes were activated with the 6-DMAP, the best pronucleus formation, cleavage, and in vitro development rate were obtained in the 2mM for 2hr~4.5hr(57.3%, 58.4% and 29.0%, respectively). 4. When the porcine oocytes were activated with the cycloheximide, result showed that pronucleus formation, cleavage, and in vifro development rate were 52.1%, 47.7% and 31.8%, respectively, in the 5$\mu\textrm{g}$/ml for 4hr~6hr treatmrent, which was significantly higher than all of the other treatment. These results suggested that the active condition of porcine oocytes was established by optimum concentration and exposure time among different chemicals for produce of large quantity recipient oocytes.s.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.13-20
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• 2006

The purpose of this study was to develope the transgenic cattle expressing hFSH into the urine using the nuclear transfer. To produce the interest gene in urine, the specific vector was ligated with hFSH gene undo. maUII promoter. The fetal fibroblast cells (KbFF) were isolated from a 45-day male fetus. The hFSH gene was co-transfected with pcDNA3 (neo) vector to KbFF cells by electroporation. The gene-transfected cells were cultured with G-418 selection medium for 2 weeks. Selected colonies were confirmed by PCR. For nuclear transfer, enucleated bovine oocytes were transferred with hFSH transfected or nontransfected fetal fibroblasts. The cleavage and blastocyst formation rates were significantly lower (p<0.05) in cloned embryos transfected with hFSH gene (68.7% and 15.7%) than in those non-transfected (67.6% and 24.5 %), respectively. Apoptosis analysis showed no difference between hFSH transfected and non-transfected blastocysts (p>0.05). The blastocysts were transfected to 77 (control 24, hFSH 53) recipient cows. Two calves were born (1.9%) following transfer with NT embryos transfected with hFSH gene, but they were confirmed not to be transgenic calves. This result shows that the hFSH colonies were mixed with transfected and non transfected cells. Further research will be needed for selection and establishment of gene transfected cells.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.127-132
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• 2004

This study was conducted to examine the effects of electric stimulation conditions on in vitro developmental ability of caprine embryos after somatic cell nuclear transfer. Recipient oocytes were surgically collected after superovulation by using CIDR and FSH, PMSG, hCG and estrous synchronization in Korean native goats. The caprine ear cells were cultured in vitro in serum-starvation condition (TCM-l99 + 0.5% FBS) for 3 to 5 days of cell confluence. The zona pellucida of in vivo and in vitro matured oocytes were partially drilled using laser system. Single somatic cell was individually transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3M mannitol. After the electofusion, embryos were activated by electric stimulation or Ionomycin + 6-DMAP. Nuclear transfer embryos were cultured in mSOF medium supplemented with 0.8% BSA 6∼7 days at 39 , 5% $CO_2$, 5% $O_2$, 90% $N_2$. The fusion rate of donor cells was 60.4% and 40.3 % in ear cell and fetal fibroblast, and cleavage rate were 40.6% and 48.2%, respectively. No significant difference was found in the fusion and cleavage rate in different donor cells. Nuclear transferred oocytes were fused by electric pulses of 1.30∼1.40, 2.30∼2.39 and 2.40∼2.46 ㎸/cm. There was no significant difference among different electric pulses in fusion rates (26.7, 34.8 and 43.8%). The cleavage rate was higher (p<0.05) in 1.30∼1.40 ㎸/cm (82.9%) than 2.30∼2.39 ㎸/cm (43.8%) and 2.40∼2.46 ㎸/cm. (51.8%). The fusion rates of recipient oocyte source were 1st (43.5% and 23.6%), 2nd (55.7％ and 39.2%) and 3rd (66.1% and 52.8%) in in vivo and in vitro oocytes. However, fusion ratee were significantly higher (p<0.05) in in vivo than in vitro oocyte. The cleavage rate of fused oocytes from in vivo and in vitro sources were 52.6% and 54.4%, respectively. No significant difference was found in the cleavage rate according to the recipient oocyte source. These results suggest that factors such as field pulse of electric stimulation and oocyte source could affect in vitro developmental ability of nuclear transplanted caprine oocytes.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.266-273
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• 2007

Heat shock proteins (HSPs) are a family of highly conserved proteins playing an important role in the functioning of unstressed and stressed cells. The HSP70 family, the most widely studied of the hsps, is constitutively expressed (hsc70) in unstressed cells and is also induced in response to stressors (hsp70), especially those affecting the protein machinery. The HSP/HSC70 proteins act as molecular chaperones and are crucial for protein functioning, including folding, intracellular localization, regulation, secretion, and protein degradation. Here, we report the identification and characterization of the putative amino acid sequence deduced from one cDNA clone identified as heat shock protein 70. The alignment showed that the putative sequence is 100% identical to the heat shock protein 70 cognate (HSC 70) of olive flounder. The 5'-flanking region sequence (approximately 1 kb) ahead of the hsc70 gene was cloned by genome walking and a putative core promoter region and transcription elements were identified. We characterized the promoter of the olive flounder hsc70 gene by examining the ability of 5'-upstream fragments to drive expression of green fluorescent protein (GFP) in live embryos.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.187-195
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• 2003

This study was carried out to improve of enucleation efficiency on porcine recipient oocytes preactivated. In ethanol or $Ca^{2+}$ ionophore, effect of repeating and combinational activation with 6-DMAP or cycloheximide compared with alone activated treatment. Recipient oocytes's activation by $Ca^{2+}$ ionophore combined with 6-DMAP or cycloheximide were significantly higher than alone treatment(P<0.05). Between repeating and alone treatments were not significantly different. In ethanol, repeating treatment was significantly lower than alone(P<0.05), and combination treatments were not significantly different. On the basis of these results, efficiency of enucleation, electrical fusion and in vitro development compared preactivated with non-preactivated recipient oocytes. Enucleation and fusion rates of preactivated oocytes were improved significantly compared with non-preactivated oocytes(90.7%, 71.8 vs 77.8%, 61.1%; P<0.05). Behind the back, cleavage and in vitro development rates were significantly lower than non-preactivated oocytes(38.7%, 19.3% vs 68.8%, 30.6%; P<0.05).

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.83-91
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• 2005

Somatic cell nuclear transfer in cattle has limited efficiency in terms of production of live offspring due to high incidence of fetal failure after embryo transfer to recipients. Such low efficiency of cloning could possibly arise from abnormal and poorly developed placenta. In the present study the placental proteome in late pregnancy established from in vitro fertilization (IVF) and nuclear transfer (NT) was analysed. Proteome alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI- TOF). Comparing placenta from NT embryos to those from IVF counterparts, significant changes in expression level were found in 18 proteins. Of these proteins 12 were not expressed in NT placenta but expressed in IVF counterpart, whereas the expression of the other 6 proteins was limited only in NT placenta. Among these proteins, cytokeratin 8 and vimentin are considered to be involved in regulation of post-implantation development. In particular, cytokeratin 8 and vimentin may be used as makers for placental development during pregnancy because their expression levels changed considerably in NT placental tissue compared with its IVF counterpart. Data from 2-DE suggest that protein expression was disorientated in late pregnancy from NT, but this distortion was eliminated with progression of pregnancy. These findings demonstrate abnormal placental development during late pregnancy from NT and suggest that alterations of specific placental protein expression may be involved in abnormal function of placenta.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.215-220
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• 2007

This study was conducted to examine the establishment of bovine ES-like cells having pluripotency. The hatched blastocysts derived from culture of in vitro fertilized embryos for 10 to 12 days dissociated mechanically into ICM-and trophectoderm-rich clumps using needle, and cultured onto mitotically-inactivated MEF feeder layer. The primary colonies originated from ICM cells were detached mechanically 7 days after seeding and subsequent subculture was conducted at intervals of every 5 to 7 days. Two ES -like cell lines were established and maintained over 40 passages. Self-renewal of the established lines was confirmed by examining the alkaline phosphatase activity, stem cell-specific marker profiles including SSEA isotopes, Oct-4 and STAT3. Moreover, the established cell lines could produce anchorage-independent embryoid bodies (EBs) with gradual decrease of Oct-4 transcript level in time-dependent manner.

• Journal of Embryo Transfer
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• v.31 no.1
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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.

• Journal of Embryo Transfer
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• v.16 no.3
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• pp.223-231
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• 2001

The success of nuclear transplantation with mammalian oocytes depends critically on the potential of oocytes activation, which mainly caused to prevent the re-accumulation of maturation promoting factor (MPF). This study was conducted to compare the effect of combined treatment of lonomycin with a Hl-histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on activation of bovine oocytes. In vitro matured bovine oocytes with the first polar body (PB) and dense cytoplasm were assigned to 3 experimental groups. For activation treatment, oocytcs were exposed to 5 $\mu$M lonomycin for 5 min (Group 1), and followed by 1.9 mM dimethylaminopurine (DMAP) for 3 h (Group 2) or followed by 2 mM sodium pyrophosphate (SPP) for 3 h (Group 3). The activation effects in the three treatments and the control group (untreated) were judged by the extrusion of the second PB and formation of a pronucleus (PN). Differences among groups were analysed using one-way ANOVA after arc-sine transformation of proportional data. All three treatments led to high activation rates (90% to 95%), with significant difference from the control. However, the extrusion of the second PB and the rate of PN formation differed remarkably among treatments. In Group I and 3, about 95% of the oocytes had extruded the second polar body, but one PN had formed in a higher proportion of oocytes in Group 3 than in Group 1 (90% vs. 5%). In experiment 2, the rates of cleavage and development into blastocysts in Group 1 were significantly lower than those of Group 2 and 3 (8.7% and 0% vs. 50.5% and 11.6%, and 44.6% and 7.2%, respectively, P<0.05). In experiment 3, ~80% of parthenotes in Group 1 were developed with haploid chromosomal sets. However, when ionomycin was followed immediately by DMAP (Group 2). only 20% of parthenotes were haploid. In Group 3, combined treatment with ionomycin and SPP, the appearance of abnormal chromosomal tracts was significantly (P〈0.05) reduced and the proportion of haploid parthenotes was increased to 85% (17/20) than in Group 2. These results demonstrate that SPP acted as a cdc2 kinase inhibitor and formed the haploidy in oocyte activation. Thus, the present study suggests that cdc2 kinase inhibitor, such as sodium pyrophosphate, may have an effective role in oocyte activation for the production of cloned embryos/animals by nuclear transplantation.