• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.399-407
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• 2001

The microinjection of retroviral vectors into the perivitelline spaces of MII-stage oocytes increased production of transgenic bovine embryos. However, oocytes have various sizes of perivitelline space, and there is the tendency that the oocyte membranes are damageable by micropipettes during the injection of retroviral vectors into perivitelline spaces or oocytes. Thus, it was not always possible to stably inject retroviral vector into perivitelline spaces of oocytes. Here we used sucrose to minimize the damage of the oocyte membrane. When the oocytes were suspended in 0.5% sucrose, poor quality oocytes showed rough cytoplasmic membranes, while good quality oocytes maintained smooth membranes. However, when the tatters were subjected to in vitro fertilization, no significant differences were observed in cleavage rates (82% of control Vs. 84% of sucrose treated oocytes). The Same trends were obtained from the oocytes fertilized after microinjection of LN$\beta$-EGFP and LNC-hGH genes into the perivitelline spares. The rates of cleavage and blastocyst from microinjection of LN$\beta$-EGFP genes were 81 and 25%, and from microinjection of LNC-hGM genes were 53 and 30%, respectively. The result indicated that microinjected oocytes could develop to the blastocyst stages after in vitro fertilization with no significant difference from control group. Moreover, the integration of hGH-gene (by PCR analysis) was detected in 52% of infected cleaved embryos and the expression of EGFP-gene (under a fluoresrence microscope) was also observed in 34% of infected blastocyst. These results indicated that 0.5% sucrose treatment could be an efficient method not only to select good quality embryos but also to inject retroviral vectors into perivitelline spares without any harm and hence improving developmental rates.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.153-158
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• 2011

Objective: The aim of this study was to investigate whether anti-M$\ddot{u}$llerian hormone (AMH) levels could be predict ovarian poor/hyper response and IVF cycle outcome. Methods: Between May 2010 and January 2011, serum AMH levels were evaluated with retrospective analysis. Three hundred seventy infertile women undergoing 461 IVF cycles between the ages of 20 and 42 were studied. We defined the poor response as the number of oocytes retrieved was equal or less than 3, and the hyper response as more than 25 oocytes retrieved. Serum AMH was measured by commercial enzymelinked immunoassay. Results: The number of oocytes retrieved was more correlated with the serum AMH level (r=0.781, $p$ <0.01) than serum FSH (r=-0.412, $p$ <0.01). The cut-off value of serum AMH levels for poor response was 1.05 ng/mL (receiver operating characteristic [ROC] curves/area under the curve [AUC], $ROC_{AUC}$=0.85, sensitivity 74%, specificity 87%). Hyper response cut-off value was 3.55 ng/mL $ROC_{AUC}$=0.91, sensitivity 94%, specificity 81%). When the study group was divided according to the serum AMH levels (low: <1.05 ng/mL, middle: 1.05 ng/mL - 3.55 ng/mL, high: >3.55 ng/mL), the groups showed no statistical differences in mature oocyte rates (71.6% vs. 76.5% vs. 74.8%) or fertilization rates (76.9% vs. 76.6% vs. 73.8%), but showed significant differences in clinical pregnancy rates (21.7% vs. 24.1% vs. 40.8%, $p$=0.017). Conclusion: The serum AMH level can be used to predict the number of oocytes retrieved in patients, distinguishing poor and high responders.

• Journal of Aquaculture
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• v.10 no.4
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• pp.463-472
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• 1997

Floating and hatching rates, size and survival activity index(SAI) of spawned eggs of red spotted grouper, Epinephelus akaara were studied to understand egg qualities during the spawning periods in 1992, 1993 and 1995. The fish spawned from mid-July to mid-August when temperature ranged 23~$28^\circC$. Floating, fertilization and hatching rates were higher in the eggs from early to middle than those from late during the spawning period. SAI ranged 1.8~9.6, and it was closely related to survival rate until mouth operning time (SMOT). Egg diameter decreased gradually with the time of spawning, while diameter of oil globule was constant during the spawning periods. Induced spawnings were carried out with one injection of HCG over 5, 000 IU/kg body weight. Floating, fertilization and hatching rates of the induced spawning eggs were higher than those of untreated ones. Thus, induced spawning method with HCG was recommended for collecting fertilized eggs in bulk. Optimal time for the collection of high quality eggs was supposed to be from early to middle during the spawning periods. Considering that egg qualities were vulnerable within the period, hatchability, incidence of malformed larvae, SMOT and SAI were factors to be considered together to get good quality of eggs.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.78-78
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• 2002

The role of heat shock proteins in shielding organism from environmental stress is illustrated by the large-scale synthesis of these protein by the organism studied to date. However, recent evidence also suggests an important role for heat shock protein in fertilization and early development of mammalian embryos. Effects of elevated in vitro temperature on in vitro produced bovine embryos were analysed in order to determine its impact on the expression of heat shock protein 70 (HSP70) by control and frozen-thawed after in vitro fertilization (IVF) or nuclear transfer (NT). The objective of this study was to assess the developmental potential in vitro produced embryos with using of the various containers and examined expression and localization of heat shock protein 70 after it's frozen -thawed. For the vitrification, in vitro produced embryos at 2 cell, 8 cell and blastocysts stage after IVF and NT were exposed the ethylene glycol 5.5 M freezing solution (EG 5.5) for 30 sec, loaded on each containers such EM grid, straw and cryo-loop and then immediately plunged into liquid nitrogen. Thawed embryos were serially diluted in sucrose solution, each for 1 min, and cultured in CRI-aa medium. Survival rates of the vitrification production were assessed by re-expanded, hatched blastocysts. There were no differences in the survival rates of IVF using EM grid, cryo-loop. However, survival rates by straw were relatively lower than other containers. Only, nuclear transferred embryos survived by using cryo-loop. After IVF or NT, in vitro matured bovine embryos 2 cell, 8 cell and blastocysts subjected to control and thawed conditions were analysed by semiquantitive reverse transcription polymerase chain reaction methods for hsp 70 mRNA expression. Results revealed the expression of hsp 70 mRNA were higher thawed embryos than control embryos. Immunocytochemistry used to localization the hsp70 protein in embryos. Two, 8-cell embryos derived under control condition was evenly distributed in the cytoplasm but appeared as aggregates in some embryos exposed frozen-thawed. However, under control condition, blastocysts displayed aggregate signal while Hsp70 in frozen-thawed blastocysts appeared to be more uniform in distribution.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.259-264
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• 1996

This study was carried out to investigate on the survival rates and in vitro developmental rates of bisected bovine embryos were by manipulator and micropipette. Bisected embryos were co-cultured in 20% FCS(v/v)＋TCM-199 media containing hormones, oviductal epithelial cells and cumulus cells 0 to 72 hrs after bisection. Survival rate and in vitro fertilization rate were defined as development rate on in vitro culture or FDA-test. The results are summarized as follows ; 1. The in vitro developmental rate of biseciton embryos co-cultured in 20% FCS＋TCM-199 medium containing PMSG, hCG, PMSG＋hCG, hCG＋$\beta$-estradiol 0 to 20 hrs and 20 to 40 hrs were 36.7, 26.7, 33.3, 40.0, and 30.0, and 30.0, 33.3, 30.0, 26.7, and 26.7%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing hormones was significantly higher than that of non co-culture(25.0%). 2. The in vitro developmental rates of bisection embryos co-cultured in 20% FCS＋TCM-199 medium containing oviductal epithelial cells 4 to 5 hrs and 20 to 24 hrs were 40.0 and 33.3%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing oviductal epithelial cells was significantly higher than that of non co-culture(25.0%). 3. The in vitro developmental rates of bisection embryos co-cultured in 20% FCS＋TCM-199 medium containing cumulus cells 4 to 5 hrs and 20 to 24 hrs were 43.3 and 36.7%, respectively. The survival rate of bisection embryos co-cultured in TCM-199 medium containing cumulus cells was significantly higher than that of non co-culture (25.0%).

• Clinical and Experimental Reproductive Medicine
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• v.20 no.2
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• pp.101-105
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• 1993

This study was carried out to improve pregnancy rate in IVF-ET program through Assisted Hatching (AH) by the use of micromanipulation technique. Among 72 IVF patient, randomized 29 IVF patients were performed for AH by Partial Zona Dissection(PZD). Two to eight cell embryos were micromanipulated just before uterine transfer. The results were as follows: 1. The implantation rates of embryos between PZD group and control group were 10.0%, 4.9%, respectively. 2. The clincal pregnancy rates of both groups were 34.5%,20.9%, respectively. 3. Among 131 PZD embrys, only 2 embryos were damaged mechanically. Although there were no statistical difference in the rates of implantation and pregnancy between PZD group and control group due to small sample size, the PZD group had increasing trend in the rates of implantation and pregnancy. In conclusion, it would be thought that PZD could be adequately used to improve implantation rate and pregnancy rate in IVF-ET program as an assisted technique if much more studies were done. Also the risks resulting from this study can be reduced because of technical stability, which showed the low rate of damaged embryos.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.378-380
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• 2012

BACKGROUND: In Korea, green manure has been cultivated for reducing chemical fertilizer application, maintaining soil fertility, and feeding livestock in winter season. We evaluated the phosphate balance under green manure-rice cultivating system with different removal rates of green manure for maintaining soil fertility. METHODS AND RESULTS: The barley and hairy vetch mixture was selected as the green manure in this study. The barley and hairy vetch was sowed at a rate of 135 and 23 kg/ha, respectively, without fertilizer application. Total aboveground biomass was 12000 (barley: 5400 kg/ha, hairy vetch: 6600 kg/ha) kg/ha, and these green manure were incorporated with different input rates before rice planting. The input rates of green manure in this study were 0 (NPK+0%), 25 (NPK+25%), 50 (NPK+50%), 75 (NPK+75%) and 100 % (NPK+100) and the standard fertilization (NPK) without green manure cultivation. All treatments were applied with standard fertilizer (N-P-K: 90-19.6-48.3 kg/ha) before rice planting. The highest rice yield was observed in NPK+50% which was 20% higher compared with NPK. The phosphate balance with different incorporation rates of green manure was-104.0,-76.8,-52.9,-27.4, and 6.0 kg/ha for NPK+0%, NPK+25%, NPK+50%, NPK+75%, and NPK+100%, respectively. CONCLUSION(S): The use of green manure for livestock feeding in green manure-rice cropping systems could remove a huge amount of phosphate. This cropping system strongly requires phosphate application before green manure seeding for maintaining soil fertility.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.105-110
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• 2017

Objective: The purpose of this study was to evaluate the efficacy of frozen mixed double-embryo transfer (MDET; the simultaneous transfer of day 3 and day 5 embryos) in comparison with frozen blastocyst double-embryo transfer (BDET; transfer of two day 5 blastocysts) in patients with repeated implantation failure (RIF). Methods: A total of 104 women with RIF who underwent frozen MDET (n = 48) or BDET (n = 56) with excellent-quality embryos were included in this retrospective analysis. All frozen embryo transfers were performed in natural cycles. The main outcome measures were the implantation rate, clinical pregnancy rate, multiple pregnancy rate, and miscarriage rate. These measures were compared between the patients who underwent MDET or BDET using the chi-square test or the Fisher exact test, as appropriate. Results: The implantation and clinical pregnancy rates were significantly higher in patients who underwent MDET than in those who underwent BDET (60.4% vs. 39.3%, p=0.03 and 52.1% vs. 30.4%, p=0.05, respectively). A significantly lower miscarriage rate was observed in the MDET group (6.9% vs. 10.7%, p=0.05). In addition, the multiple pregnancy rate was slightly, but not significantly, higher in the MDET group (27.1% vs. 25.0%). Conclusion: MDET was found to be significantly superior to double blastocyst transfer. It could be regarded as an appropriate approach to improve in vitro fertilization success rates in RIF patients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.73-78
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• 2000

This study was conducted for 2 years at Chinju region to establish suitable seeding rate and fertilizing levels of nitrogen, phosphorous and potassium in spring-sown Jinyangbori. Heading and maturing were delayed by increasing fertilizers, especially nitrogen. Number of spikes per were secured by much seeding and increased application of nitrogen. One thousand grain weight reduced with increasing fertilization at any seeding rate. Relatively high harvest indices were observed with 12-10-4 at 10kg. 10a$^{-l}$ seeds planted, followed by 6-10-8 at 15 kgㆍ 10a$^{-1}$, and 6-10-4kgㆍ 10a$^{-l}$ at 20kg ㆍ 10a$^{-l}$ of N-P-K fertilizing combinations, respectively. There was no distinct differences on yield for various seeding rates in spring-sown barley. When seeding rate increased up to 15kgㆍ10a$^{-1}$, the positive effect of fertilizers was recognized as the function of balanced-application. It was possible to recommend 10kgㆍ10a$^{-1}$ as seeding rate and 6-5-4(N-P-K)kgㆍ10a$^{-1}$ as fertilizing combination in spring-time seeding considering low input and sustainable agriculture. There was no significant difference of protein content in grain by seeding rate. Increase of nitrogen fertilizer enhanced protein content in grain.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.479-485
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• 2020

We evaluated the hatchability of fertilized eggs from six hybrid combinations of highly valued grouper species inhabiting temperate and warm waters, with the goal of establishing a novel hybrid with enhanced growth and viability during the culturing period in the temperate waters of Korea. Hybrid combinations with red-spotted grouper females exhibited high hatchability with high a fertilization and hatching rate of fertilized eggs and a low deformity rate of hatched larvae. Conversely, hybrid combinations with kelp grouper females had very low hatching rates and very high deformity rates; commercial production of seed from such crosses would be difficult without improving hatchability. The hatchabilities of convict grouper ♀×giant grouper ♂ and kelp grouper ♀×red-spotted grouper ♂ were lower than those of maternal purebreds, but these two hybrid combinations were expected to produce potentially large quantities of hatched larvae. In the above evaluation, promising hybrid combinations were identified for commercial production of seed. For these hybrids to contribute to the development of Korea's mariculture industry, mass production of fertilized eggs and seeds is necessary, along with the development of advanced rearing techniques, such as the identification of a suitable rearing temperature.