• Journal of Embryo Transfer
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• v.28 no.3
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• pp.163-168
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• 2013

Embryo transfer (ET) technology is of high importance in modern cattle breeding programs. ET is one step in the process of removing one or more embryos from the reproductive tract of an outstanding donor female and transferring them to one or more recipient females. Embryos also can be produced in the laboratory via techniques such as in vitro fertilization (IVF). But the actual transfer of an embryo is only one step in a series of processes that may include some or all of the following: superovulation and insemination of donors, collection of embryos, isolation, evaluation and short-term storage of embryos, micromanipulation and genetic testing of embryos, freezing of embryos and embryo transfer. Cryopreservation and direct transfer of frozen-thawed embryos is common-place with pregnancy rates near that of fresh embryos. Polymerase chain reaction (PCR) technology is currently being used for sexing embryos, and this technology will be used for "embryo diagnostics" and "embryo genomics" in the future. Although, many limitations and problems remain to overcome, these and other new technologies promise to change livestock breeding drastically in the next decade.

• ALGAE
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• v.24 no.3
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• pp.139-147
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• 2009

Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.478-481
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• 1997

A technique or the preparation of porous polyurethane vascular prostheses was investigated. Small-diameter vessels are not in general clinical use due to their limited long-term biocompatibility and low patency rates in experimental trial. These limits are mainly due to the failure of mechanical unction of the vascular grafts. This failure has been suggested to result partially from compliance mismatch. The long-term patency is considered to depend critically on the properties of the material and the fabrication process of the graft. So the control of pores is very important and main points to develop a available vascular grafts. Two-kind polymer sheets was compared. One was the porous PU-sheet made at room temperature by the solvent/non-solvent exchange. And the other was the porous PU-sheet which was fabricated by thermal phase transition and solvent-/non-solvent exchange using the thermal controller. The polymer sheets had a uniform pore size and pore occupation. According to the result of the above experiments, polyurethane solution was injected into a mold designed or U-type tube. The average pore size and pore occupation were easily changed by changing polyurethane concentration, freezing temperature, and methods. This technique can give a proper pore size ($10{\sim}45\;{\mu}m$) or tissue in growth, and suitable compliances or matching with arteries and veins. Besides, the fabrication of more complicated shaped vessels such as the U-type vascular grafts is easily controlled by using the fixed mold. this method might give a desired compliant graft or artificial implantation with the presently valid medical polymers.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.183-191
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• 1995

This experiment was carried out to study the determination of survival of vitrified and thawed mammal follicular oocytes by FDA-test. Oocytes were divided into 3 groups according to attachment of cumulus cell. Group A oocytes were tightly surrounded by cumulus cell, group B oocytes were partially surrounded by cumulus cell, and group C oocytes were poorly surrounded by cumulus cell. Vitrification solution developed by our previous study (Kim et al, 1992) which consisted of permeable agent (20 % glycerol + 10 % ethylene glycol) and nonpermeable agent (30 % Ficoll + 10 % sucrose). Oocytes (7~10) loaded into 0.25 ml straw after 10 min equilibration were plunged into liquid nitrogen (- 196$^{\circ}C$) directly. The FDA-score of vitrified and thawed group A oocytes was higher in rat (4.2) than in rabbit (3.9), cow (3.8), mouse (3.4) and porcine (2.4), however that of cumulus cell was higher in rabbit (4.7) than in rat (4.1), cow (2.9), porcine (2.6) and mouse (1.4). The FDA-score of vitrified and thawed group B oocytes were 3.1 (cow), 2.9 (rabbit), 2.9 (mouse), 2.6 (rat) and 2.5 (porcine), respectively. However that of cumulus cell was higher in rabbit (3.7) than in porcine (2.6), rat (2.3), cow (1.7) and mouse (0.3). The FDA-score of vitrified and thawed group C oocytes was higher in mouse (4.1) than in cow (2.9), rabbit (2.6), rat (1.3) and porcine (1.1). As shown in the above results, The survival rates of oocytes were higher in group A than in group B and C except in mouse and cow. These results suggest that the survival of cumulus cell as well as follicular oocytes can be reliably judged by their fluorescence with FDA-test.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.261-265
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• 2004

The present study was conducted to assess sperm characteristics in miniature-pig. The semen samples were transported to the laboratory at 17℃ within 3 hours after collection. The extended semen was stored at 17℃, and sperm quality was evaluated at 0, 1, 3, 5 and 7 days after storage. The semen volume of miniature-pig (62±22㎖) was significantly (p<0.05) lower than that of Duroc (155±25㎖) and Yorkshire (154±23㎖). Significant differences were also observed in sperm concentrations. During 3 days of storage, sperm viability did not differ among miniature-pig, Duroc and Yorkshire. However, the viability was significantly (p<0.05) lower in miniature-pig than in Duroc and Yorkshire semen after Day 3 of storage. In abnormality, acrosome intactness and intensity, there were no differences among miniature-pig, Duroc and Yorkshire semen. On the other hand, the viability of frozen-thawed sperm in miniature-pig was significantly (p<0.05) lower than in that of Duroc and Yorkshire. This study also examined CTC patterns in frozen-thawed spermatozoa. The rates of AR pattern were higher in miniature-pig than in Duroc and Yorkshire. However, no difference was found in F, B and AR patterns. The results of present study suggest that further research is necessary to develop of semen extender and freezing methods to improve sperm quality in miniature-pig.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.657-665
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• 2020

The objective of this study was to investigate whether supplementation of pentoxifylline (PTX; phosphodiesterase inhibitor) to thawed boar semen improves the post-thaw motility of sperm and affects the efficiency of artificial insemination (AI) and further development. To determine the concentration of PTX for AI, frozen-thawed semen was incubated with 0, 5, 10, and 20 mM PTX in an extender freezing medium, respectively, after thawing. Kinematic properties of sperm were examined with a computer-assisted semen analysis (CASA) system. In addition, viability and mitochondrial activity were also tested by LIVE/DEAD and a MitoTracker kit. There were no significant differences in the kinetic parameters of thawed sperm between control and treatment groups, but overall assessment parameters such as motility and rapid progressive were higher in the 10 mM PTX group. In the viability and mitochondrial assay, there were no significant differences observed in the PTX treatment, compared to the control. For further analysis, artificial inseminations were performed using frozen semen and 10 mM PTX treated cryopreserved semen, respectively. There were no differences in pregnancy rates and fetus weights among the groups until 30 and 40 days, but litter size was reduced and relatively low-birth weight was observed in the PTX group. In summary, our findings suggest that enhancement of in vitro sperm quality or non-toxicity supplemented by PTX may have detrimental effects on fetus development.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.281-287
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• 2009

As a simple and economical method for in vitro produced embryos, we have used BSA instead of serum for the production and embryo transfer of Hanwoo in vitro fertilized (IVF) embryos and obtained the following results: 1) When using serum (FBS; fetal bovine serum) or BSA-containing culture media as the initial culture media for immature oocytes, it is regarded as inappropriate to add only BSA to the culture solutions from maturation of the immature oocytes to development stage culture, but serum still needs be added though there is no significant difference in the concentration, with a change from 5% to 10%. 2) The results of culturing IVF embryos after development (4 cell stage) in the Medium199 solutions containing BSA instead of serum (FBS) showed that 0.3% BSA concentration is not optimal and 0.5% or higher BSA concentration has no significant difference among 0.5%, 0.7%, 1% and 2% (p > 0.05). 3) The post-freezing survival ratio after development in 5% FBS-Medium199 showed that 1% BSA concentration of the culture solution is the most suitable in the BSA concentrations of 0.3% (51%), 0.5% (67%), 0.7% (69%), 1% (77%) and 2% (75%). 4) The pregnancy rates of the transplanted fresh(not frozen) blastocyst had no significant concentration dependency (p > 0.5), and the average pregnancy rate was 63.8%. 14% of overweight calves were found among the calves given birth to by the transfer of IVF blastocysts cultured in the serum-added culture solution, but none was found in the experimental groups in which BSA was added instead of serum.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.299-306
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• 2021

Vitrification methods are commonly used for mammalian reproduction through the long-term storage of blastocyst produced in vitro. However, the survival and quality of embryos following vitrification are significantly low compared with blastocyst from in vitro production (IVP). This study evaluates that the survival of frozen-thawed bovine embryos was relevant to mitochondrial superoxide derived mitochondrial activity. Here we present supplementation of the cryopreservation medium with Mito-TEMPO (0.1 µM) induced a significant (p < 0.001; non-treated group: 56.8 ± 8.7%, reexpanded at 24 h vs Mito-TEMPO treated group: 77.5 ± 8.9%, re-expanded at 24 h) improvement in survival rate of cryopreserved-thawed bovine blastocyst. To confirm the quality of vitrified blastocyst after thawing, DNA fragmentation of survived embryos was examined by TUNEL assay. As a result, TUNEL positive cells rates of frozen-thawed embryos were lower in the Mito-TEMPO treated group (4.2 ± 1.4%) than the non-treated group (7.1 ± 3.5%). In addition, we investigated the intracellular ROS and mitochondrial specific superoxide production using DCF-DA and Mito-SOX staining in survived bovine embryos following vitrification depending on Mito-TEMPO treatment. As expected, intracellular ROS levels and superoxide production of vitrified blastocysts after cryopreservation were significantly reduced (p < 0.05) according to Mito-TEMPO supplement in freezing medium. Also, mitochondrial activity measured by MitoTracker Orange staining increased in the frozen-thawed embryos with Mito-TEMPO compared with non-treated group. These results indicate that the treatment of Mito-TEMPO during cryopreservation might induce reduction in DNA fragmentation and apoptosis-related ROS production, consequently increasing mitochondrial activation for developmental capacity of frozen-thawed embryos.

• Journal of Embryo Transfer
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• v.16 no.2
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• pp.117-125
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• 2001

Vitrification of oocytes has been applied recently fur pigs, but remains elusive. The purpose of this study is to investigate the effects of vitrification in open pulled straws (OPS) on in vitro survival of porcine oocytes. When immature follicular oocytes frozen-thawed were cultured for in vitro maturation, maturation rates to metaphase-II stage were higher in oocytes with (25%) than without (15%) cumulus cells. After In vitro fertilization of oocytes frozen-thawed, the maturation rates were also significantly (P<0.05) higher in oocytes with (41%) that than without (17%) cumulus cells. However, the penetration rates were higher in oocytes without (19%) that than with (9%) cumulus. In another experiment, porcine oocytes matured in vitro were frozen and thawed for in vitro fertilization. The penetration rates were higher than in oocytes without (35%) that than with (26%) cumulus cells. However, the proportions of oocytes dead after in vitro fertilization were significantly (P<0.05) higher in oocytes with that than without cumulus cells. On the other hand, the rates of penetration and dead oocytes at 6 h after in vitro fertilization were not significant differences between oocytes with and without cumulus cells. However, the proportions of dead oocytes with (18%) and without (16%) cumulus cells were higher than in oocytes of control group (0%). These finding indicated the possible broader application for OPS, as they demonstrated that the maturation and fertilization in vitro by frozen-thawed oocytes may be accompained by cumulus cells and culture periods according to the requirements of the survival ability after freezing of mature and immature oocytes in pigs.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.247-256
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• 1999

The present study was performed to improve the reproductive disturbance as well as the elimination of microbiological contamination for animals bred under conventional conditions followed by in vitro fertilization and embryo transfer techniques including embryo and sperm freezing, using a mouse strain(M. m. molossinus-tt＠Kist) showing the abnormal behavior disorder derived from Korean wild mice (Mus musculus molossinus). Moreover, hematological and serum biochemical analyses were also carried out to obtain the basic data of this mouse strain The results are summarized as follows: 1. In comparison with hematological data, the numbers of RBC and platelet of this mouse strain were appeared as the higher value those that of the same aged inbred strains such as BALB/c, DBA/2, C57BL/6 and C3H /Hen. However, no differences were found in values of WBC, Hb and Ht. Moreover, total cholesterol of this strain showed a low value but triglyceride, total protein and albumin values were similar as in inbred strains. 2. The average numbers of superovulated oocytes treated with 2.5/2.5 IU and 5.0/5.0 IU of PMSG/hCG were 11.6 and 12.7, respectively. The fertilization rates of 2.5/2.5 IU PMSG /hCG treatment(87.9%) was higher than 5.0/5.0 IU treatment(52.0%) (p＜0.05) and the developmental rate of 2 cell stage embryos were 외 so appeared as higher value 99.0% and 90.6%, respectively. 3. The rates of in vitro fertilization treated with frozen sperm(24.8%) was significantly lower than of that fresh sperm(87.9%), (p＜0.05). 4. The five, six and ten heads of offspring were obtained from frozen-thawed 2 cell embryos by in vitro fertilized, 2 cell embryos from in vitro fertilized by frozen-thawed spermatozoa. and 2 cell embryos by in vitro fertilization, respectively. These offspring developed the expected disease about 2 weeks after birth, which was confirmed that the disease character of this mutant mouse strain was reliably reproduced. 5. MHV(Mouse hepatitis virus) and Staphylococcus aureus were successfully eliminated from conventional animals by in vitro fertilization-embryo transfer and the use of SPF recipient animals.