• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.87-92
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• 1998

This study was carried out to investigate in vitro/in vivo development of vitrified mouse oocytes. Mouse oocytes were vitrified using EFS30, 35 and 40 (30, 35 and 40% ethylene glycol, 18% ficoll and 0.5 M sucrose in M2 medium). After being exposed or vitrified-thawed, oocytes of normal morphology were inseminated in vitro by $1-2\times10^6/ml$ of epididymal sperm. The rates of fertilization, in vitro/in vivo development and cell number (inner cell mass and tropectoderm cell) of blastocysts in each treatment group were examined. The results obtained in these experiments were summarized as follows: The cleavage rates were obtained in EFS35 containing 35% ethylene glycol higher than in EFS30 and EFS40. The development rate of vitrified-thawed oocytes to two-cell stage after in vitro fertilization (51.1%) was significantly different compared to that of exposed to vitrification solution without cooling (60.0%) and control (68.2%) (p<0.05). However, there were no differences in the blastocyst formation from the cleaved embryos among groups (75.0, 73.3 and 80.0%). Also, the mean number of cells per blastocysts of vitrified group $(92.5{\pm}2.9)$ was similar to that of the exposed $(98.5{\pm}5.3)$ and control $(100.9{\pm}4.8)$. In vivo development of the blastocysts derived from vitrified-thawed oocytes resulted in fetal development (50.7%) and implantation rates (80.0%) which are very similar to those of control (58.2, 78.2%). These results suggest that mouse oocytes could be cryopreserved using vitrification solution (EFS35) based on ethylene glycol.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.345-351
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• 2000

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

• Journal of Aquaculture
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• v.8 no.4
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• pp.295-306
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• 1995

The present study was performed to produce supermales and superfemales in Oreochromis niloticus by combination of induced sex reversal and diploid gynogenesis. More than $95\%$ of female was obtained by oral administration of $17\beta-estradiol$ (480 mg/kg diet) to the eutheroembryonic larvae of this species. The result of progeny tests with XY pseudofemales showed that incidences of male progeny were ranged from $71.4\%\;to\;73.7\%$. p.opo.lion of male from XY pseudofemale was not significantly different (P>0.05) from that of $\chi^2$ (1:3), but it was significantly different (P<0.01) from that of $\chi^2$(1:1) Gynogenetic diploids were produced by applying cold shocks 3 min after insemination to the eggs of XY pseudofemale sperms were genetically inactivated by ultraviolet rays of 4,050 $erg/mm^2$. Fertilization rates of gynogenetic diploids were not different from that of their controls, however, hatching rates and early survival rates were silghtly lower than those of controls. In the cytogenetic studies, there was no difference in the size of cell and nucleus between the gynogenetic diploids and the controls. At 80 days after hatching, frequencies of gynogenetic male were higher than those of gynogenetic female (P<0.01) in their population.

• Journal of Aquaculture
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• v.8 no.4
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• pp.317-326
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• 1995

In order to evaluate three species of diatoms as the live food sources for rearing larvae of sea urchin, Strongylocentrotus intermedius, six different feed experiments were conducted for 35 days. We measured sizes, survival rates on elapsed day after hatching and required days of each larval stages of sea urchin in the different feeding experiments. Sizes of the larvae of sea urchin cultured with Isochrysis + Chaetoceros, Isochrysis, Chaetoceros and Pavlova were $735{\mu}m$, $718{\mu}m$, $701{\mu}m$ and $642{\mu}m$, respectively. The highest daily growth rates of the larvae of sea urchin showed Isochrysis within 6 armed and Chaetoceros after 6 armed. Survival rates of the larvae of sea urchin cultured with Chaetoceros, Isochrysis + Chaetoceros, Isochrysis and Pavlova were $37.2\%,\;35.0\%,\;32.4\%,\;and\;18.4\%$, respectively. The required days from fertilization to the 8 armed (Senior) stage in the larvae of sea urchin, fed Chaetoceros, Isochrysis, Paviova, chaetocerost+pavlova, pavloua + Isochrysis and Isochrvsis + chaetoceros were 24, 27, 33, 28, 30 and 25 days, respectively.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.131-137
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• 1997

This study was carried out to investigate the in vivo development rates of vitrified-thawed mouse expanding, hatching and hatched blastoc ysts(BL). In vitro fertilization produced blastocysts were vitrified in EFS40(40% ethylene glycol, 30% Ficoll and 0.3 M sucrose in phosphate buffer saline containing 10% FBS). Expanding a and hatching blastocysts were equilibrated in 20% ethylene glyco](EG) for 5 min. before exposure to EFS40 at 25°C for 1 min., they were then vitrified in liquid nitrogen. Hatched blastocysts which cultured in m-CR1 medium supple mented 0.4% bovine serum albumin on day 5. were equilibrated in 10% EG for 5 min. and then vitrified in EFS40 for 30 sec. After thawing, re-expanding blastocysts were transferred to recipients(3 day of pseudopregnant) on one or both uterine horns(6-8 embryos per a horn). Preg¬n nancy rates of recipients and implantation were a assccessed by autopsy on 15 gestation. The res¬u ults obtained in these experiments were summar¬1 ized as follows; 1) The pregnancy and live fetus rates, for vitrified expanding BL(77.8 and 25.0%) and hatching BL(77.8 and 26.4%)n vitro were not significantly difference in those of control BL (66.7 and 42.9%: 83.3 and 40.4%), respectively, 2) in vitro development of vitrified hatched BL was 34.0%. and 3) in vivo developmental rate of vitrified hatched BL was only 33.3%. These results suggested that proposed rapid vitrification p procedures used EFS40 cryoprotectant can be effectively performed in mouse expanding Ihatching blastocysts and that mouse blastocysts a after being hatched from zona pellucida can be successfully cryopreserved.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.63-69
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• 2001

This study was carried out to examine the effects of nitric oxide compounds (hemoglobin and L-NAME) on the development of porcine in vitro maturation (IVM) and in vitro fertilization (IVF) oocytes. Cumulus cell free embryos derived from porcine IVM/IVF oocytes were cultured in NCSU23 medium containing 1~5 $\mu\textrm{g}$/$m\ell$ hemoglobin added to 44 and 96hrs in culture times, and in NCSU23 medium containing 0, 10, 50 or 100mM L-NAME. The developmental rates beyond morulae stage in 0, 1 and 5 $\mu\textrm{g}$/$m\ell$ hemoglobin groups add to 44hrs in vitro culture times were 52.4%, 57.6% and 57.4%, respectively. The addition of hemoglobin groups made it slightly higher than the control group. The proportion of embryos developed to morulae and blastocysts in 1 $\mu\textrm{g}$/$m\ell$ hemoglobin add to 96hrs after in vitro culture (70.8%) was a little higher than those of 0 and 5 $\mu\textrm{g}$/$m\ell$ hemoglobin (66.2% and 62.8%). There was no significant difference in all groups (P〉0.05). The developmental rates beyond morulae stage in 0, 10, 50 and 100mM of L-NAME groups add to 96hrs after in vitro culture were 65.2%, 73.5%, 70.1% and 53.3%, respectively 10mM and 50mM L-NAME groups were significantly higher than in 0 and 100mM of L-NAME groups (P＜0.05). In conclusions, these results indicate that L-NAME (10mM, 50mM) can increase the proportion of embryos that develop into morulae and blastocysts but hemoglobin did not affect.

• Journal of Embryo Transfer
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• v.23 no.4
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• pp.269-274
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• 2008

The purpose of this study was to determine the effects of Taxol pre-treatment to in vitro matured bovine oocytes, and sucrose and trehalose added to vitrification solution on spindle morphology and embryonic development following cryopreservation. Bovine oocytes were collected from ovaries and matured in tissue culture medium 199 (TCM 199) supplemented with 10% Fetal Bovine Serum (FBS), 0.05ng/ml epidermal growth factor, 0.01 IU/ml luteinizing hormone and $1{\mu}g/ml$ estradiol for 22h in $39^{\circ}C$, 5% $CO_2$, TCM 199-HEPES containing 20% FBS was used as basic medium (BM) to prepare vitrification solution. Oocytes were pre-treated with $1\;{\mu}M$ Taxol in maturation medium for 15 min prior to vitrification. Oocytes were exposed to 1.6 M ethylene glycol (EG) and 1.3M dimethyl sulfoxide (DMSO) in BM and then were exposed to 3.2 M EG, 2.6 M DMSO and 0.5 M sucrose in BM or 3.2 M EG, 2.6 M DMSO and 0.5 M trehalose in BM. Oocytes with cumulus cells and oocytes without cumulus cells were considered as control 1 and control 2, respectively and held in TCM 199-HEPES at $39^{\circ}C$. Oocytes were frozen using modified solid surface vitrification and were stored in cryotubes in liquid nitrogen for more than 1 week. Frozen oocytes were thawed in TCM 199-HEPES containing 0.5 M, 0.25 M and 0.1 M sucrose in BM for 2 min, respectively or 0.5 M, 0.25 M and 0.1 M trehalose in BM for 2 min, respectively. Immunoflurorescence staining of oocytes was performed to assess spindle morphology and chromosome configuration of oocytes. The rates of cleavage and blastocyst were examined following in vitro fertilization. Normal spindle morphology rate of oocytes pre-treated with Taxol prior to vitrification was not higher than that of other vitrified groups. Taxol pre-treatment did not increase cleavage and blastocyst formation rates, although control groups showed significantly higher rates (p<0.05). Percentages of normal spindle and embryonic development were not significantly different among vitrified groups regardless of type of sugar. In conclusion, Taxol pre-treatment of oocytes before cryopreservation did not reduce the damage induced by vitrification and subsequently did not improve embryonic development following vitrification. Trehalose may be used as an alternative non-permeating cryoprotectant in vitrification solution.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.56-56
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• 2003

Beta-catenin is very important in early development including involvement in cell adhesion, cell signaling, and developmental fate specification. Cell-cell interaction is an important process during mammalian embryonic development. In preimplantation embryos, embryonic compaction is the process of increased cellular flattening and adhesion of junctional complexes and results in a polarized distribution. Beta-catenin is associated with embryonic compaction in mammals. Here, we examined the relationship between beta-catenin expression and compaction in porcine embryos derived from in vitro fertilization. First of all, we investigated beta-catenin expression in each embryonic developmental stage and also focused on expression pattern according to full, partial and non-compaction at morula stage. We used the immunocyto-chemical method in this research. To confirm compaction affects on the embryonic development, we compared between compaction and developmental rates to the blastocyst. The result showed that compaction and non-compaction rates were 14.6% and 63.8% at 4 days after IVF, respectively The developmental rates to the blastocyst and their total cell number were 50.9% vs 36.4% and 41.4$\pm$11.5 vs 26.8$\pm$12.7 in compaction and non-compaction groups. Although no difference was detected in the ratio of ICM to total cells between two groups, total cell number of the blastocysts in compaction group was superior to that of the blastocysts in non-compaction group (P<0.05). Expression of beta-catenin appeared in the boundary of membrane surface between blastomeres in 2- and 4-cell stage, and observed irregular pattern from 8-cell to blastocyst stage. We also investigated beta-catenin expression pattern according to the degree of compaction in the 3 groups; full, partial (>50%) and non-compaction. The expression signal in fully compacted embryos was stronger than those of partial and non-compacted embryos. Especially, beta-catenin expression appeared various patterns in morula stage suggesting the aberrant distribution of beta-catenin is affected by compaction patterns. Our results suggest that abnormal beta-catenin expression was affected by embryo quality and further development in porcine embryos in vitro.

• Journal of Animal Science and Technology
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• v.58 no.3
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• pp.11.1-11.6
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• 2016

Background: This study was investigated the effects of culture media conditions on production of eggs fertilized in vitro of embryos from ovaries of high grade Korean native cow, Hanwoo. Methods: The IVMD 101 and IVF 100 were used for in vitro maturation of selected Hanwoo oocytes and In vitro embryo culture after in vitro fertilization, respectively. The IVMD 101 and IVD 101 were used for in vitro culture and completely free of serum. Results: The cleavage rates of 2-cell embryos in reference to Hanwoo oocytes were 86.7, 92.9, and 90.1 % in the control group, IVDM101 medium and IVD101 medium, respectively which indicates that the IVDM101 medium and IVD101 medium may result favorable outcomes. The in vitro development rates of blastocysts were 12.4, 38.4 and 32.4 % in the control group, serum free IVMD101 medium and IVD101 medium, respectively. For hatched blastocysts, it was 5.3, 33.9, and 28.6 % in the control group, serum free IVMD101 medium and IVD101 medium, respectively. Hence, more favorable results were expected for the hatched blastocysts in which the IVMD101 medium and IVD101 medium were used than the control group. Average cell numbers of blastocysts were 128.3, 165.7, and 163.6 in the groups of TCM-199 + 10 % FBS medium, IVMD 101 medium, and IVD 101 medium, respectively which clearly show that the IVMD 101 and IVD 101 medium consequence significantly higher cell numbers compared to the control group (i.e., TCM-199 +10 % FBS medium). Pregnancy rate after embryo transfer was 39.6 % when the serum free medium was used which is higher than that of the medium supplemented with serum (32.8 %). In addition, stillbirth rates were 4.9 % in the group of serum free medium whereas it was 13.6 % in the serum supplemented medium (13.6 %). Conclusions: Taken altogether, serum free media, the IVMD 101 and IVD 101 represented more favorable results in the embryo development rate of embryos, cell numbers of blastocyst, and pregnancy rate. Of note, the IVMD 101 medium showed better outcomes hence, it might be a better option for future applications for in vitro culture of bovine embryos.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.261-266
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• 2001

Effects of elevated carbon dioxide ($CO_2$) on soil microbial processes were studied in a northern peatland. Intact peat cores with surface vegetation were collected from a northern Welsh fen, and incubated either under elevated carbon dioxide (700 ppm) or ambient carbon dioxide (350 ppm) conditions for 4 months. Higher algal biomass was found under the elevated $CO_2$ condition, suggesting $CO_2$ fertilization effect on primary production, At the end of the incubation, trace gas production and consumption were analyzed using chemical inhibitors. For methane ($CH_4$ ), methyl fluoride ($CH_3F$) was applied to determine methane oxidation rates, while acetylene ($C_2H_2$) blocking method were applied to determine nitrification and denitrification rates. First, we have adopted those methods to optimize the reaction conditions for the wetland samples. Secondly, the methods were applied to the samples incubated under two levels of $CO_2$. The results exhibited that elevated carbon dioxide increased both methane production (210 vs. $100\;ng\;CH_4 g^{-1}\;hr^{-1}$) and oxidation (128 vs. $15\;ng\;CH_4 g^{-1}\;hr^{-1}$), resulting in no net increase in methane flux. For nitrous oxide ($N_2O$) , elevated carbon dioxide enhanced nitrous oxide emission probably from activation of nitrification process rather than denitrification rates. All of these changes seemed to be substantially influenced by higher oxygen diffusion from enhanced algal productivity under elevated $CO_2$.