• Journal of Animal Science and Technology
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• 제66권5호
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• pp.920-935
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• 2024

Embryo transfer plays a crucial role in enhancing the breeding value of livestock; it has been applied in Hanwoo cattle, which is a popular breed for beef production in Korea. Both in vivo-derived (IVD) and in vitro-produced (IVP) embryos are used for this purpose; however, IVP embryos have been preferred recently owing to advancements in ovum pick-up (OPU) technology and genomic selection. Despite technological advancements, comprehensive data on large-scale OPU/IVEP/embryo transfer in Hanwoo cows are lacking. In this study, 16 elite Hanwoo donor cows were selected on the basis of specific criteria. Oocytes were retrieved from 241 cows using OPU. The collected cumulus-oocyte complexes (COCs) were matured, fertilized, and cultured in vitro to produce transferable embryos. Embryos were classified according to their developmental stage and then transferred to 675 recipient cows. A total of 3,317 COCs were collected, with an average of 13.76 COCs per cow. The number of transferable embryos produced per cow was 3.7. Hanwoo OPU-derived IVP embryos exhibited a higher production yield than the global average, indicating a stable IVEP environment. Both fresh and frozen IVP embryos yielded similar conception rates; hence, the use of vitrified-thawed embryos in transfer plans feasible. However, frozen-thawed embryos at Stage 7 had a lower conception rate than those at earlier stages. There was no significant difference between the conception rates of sexually mature heifers and postpartum cows used as recipients. The male-to-female offspring ratio increased as the developmental stage progressed. Seasonal effects on conception rates were not observed; however, higher abortion rates and a higher proportion of male offspring were observed during winter. This study provides valuable data for the Korean embryo transfer industry, enabling more strategic growth of the domestic Hanwoo embryo industry.

• 한국수정란이식학회지
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• 제17권3호
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• pp.211-218
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• 2002

본 연구는 체외에서 소 난포란유래의 배반포 생산에 있어서 배지 내에 첨가하는 외인성 고정질소 원으로써 아미노산과 FBS의 첨가효과를 검토하였다. 소 난포란의 체외성숙은 TCM-l99용액, 체외 수정은 Fer-TALP용액으로 행하였으며, 체외수정후 24시간째(day 1)의 수정난자를 체외배양에 제공하였다. 체외배양용 기초배지는 YS용액, 기초 배양법은 25개 난자/10 ${\mu}\ell$ 배지의 단순.미소적배양법을 이용하였다. 본 연구의 결과를 요약하면 다음과 같다. 1. 체외 수정란의 배양에 있어서 비필수 아미노산(MEM 유래) 첨가가 무첨가군보다 높은 배반포 발달율을 나타냈다. 2. 체외 수정란의 배양에 있어서 필수 아미노산(RPMI 1640 유래) 첨가가 무첨가군보다 유의하게 높은 배반포 발달율을 나타냈다. (P<0.05) 3. Day 1에 비 필수 아미노산, day 5에 필수 아미노산을 첨가하였을 경우 부화 배반포로의 발생율 및 배반포로의 부화율을 향상시켰다. 4. Day 1에 비필수.필수 아미노산을 첨가한 후 day 3, day 4, day 5에 각각 필수 아미노산만을 배지로부터 제거 시 배반포의 부화율은 현저하게 낮았다. 5. FBS의 첨가시기는 배양 후기(day 5)에 첨가할 수록 배반포율 또는 부화 배반포율이 유의하게 상승하였다(p<0.05). 이상의 결과에서 소 난포란 유래 배반포의 체외생산에 있어서 배지에 첨가하는 외인성 고정 질소 원들의 첨가에 있어서 첨가시기 및 농도를 조절함으로써 양질의 배반포 생산을 향상시킬 수 있는 것으로 사료된다.

• 대한수의학회지
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• 제38권1호
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• pp.209-216
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• 1998

The purpose of present study is to improve the efficiency of fusion and the developmental rates of nuclear transplanted embryos to produce genetically identical twins from Korean native cattle. The diameter of aspirated follicles had no significant effect on the recovery rates of oocytes collected by ovum pick-up technique. The fusion rates of nuclear transplanted embryos were significantly higher in 50 and $100{\mu}s$ DC duration groups(73.3 and 72.0% ; respectively) than that in $30{\mu}s$ group(55.6% ; p<0.05). The cleavage rates of nuclear transplanted embryos appeared to be significantly higher in donor nuclei derived from in vivo (65.0%) than in those from in vitro (50.5% ; p<0.01), but the developmental rates to morulae and blastocysts were not significantly different between them(13.7 vs 10.9%, respectively).

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.301-308
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• 2011

결빙억제제(CPA)의 종류, 농도 및 침지시간이 참전복 Haliotis discus hannai 발생배의 생존활성에 미치는 영향을 조사하였다. 4세포, 담륜자 및 피면자를 dimethyl sulfoxide, ethylene glycol, propylene glycol 농도별로 10분, 20분 및 30분간 침지하였다. CPA 침지 후 각 발생배의 발생진행률은 각 CPA 농도가 낮을수록, CPA 침지시간이 짧을수록 높았다. 또한, 피면자에서 비틀림전까지의 발생진행률은 4세포에서 담륜자까지의 것보다 높았다. CPA 침지 후 발생진행률 및 유생활성지수는 ethylene glycol에서 가장 높았다. 참전복 발생배의 냉동보존 효과를 높일 수 있는 CPA 및 농도는 ethylene glycol 2.0 M, 평형시간은 30분인 것으로 추정된다.

• 한국수정란이식학회지
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• 제11권3호
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• pp.201-210
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• 1996

This experiment was carried out to evaluate the effect of early mouse embryonic development in vitro by co-culture with bovine and porcine oviductal epithelial cells (BOEC and POEC). The 2-cell embryos were collected from the oviducts of the superovulated and mated cultured in D-PBS /15% FCS at 48 hours after hCG injection. The in vitro developmental rate of blastocyst formation in the embryos were examined under the fllowing treatments; 1) TCM 199 added 15% HCS, 2) Ham's F-10 added 15% HCS, 3) MediCult IVF medium, 4) TCM 199 added 15% HCS + BOEC, 5) TCM 199 added 15% HCS + POEC, 6) Ham's F40 added 15% HCS + BOEC, 7) Ham's F-10 added 15% HCS + POEC,8) MediCult IVF medium + BOEC, 9) MediCult IVF medium + POEC. For a comparative study of in vitro development for 96 hours after hCG injection, were cultured with oviductal epithelial cell and media only. The obtained results were 2-cell embryos developed to the blastocyst stage in TCM 199, Ham's F-10 and MediCult IVF medium at the rates of 84.4,83.2 and 81.6%. respectively. The higher developmental rates(91~97%) of blastocyst formation was appeared when the embryos were co-cultured with a monolayer of bovine or porcine oviductal epithelial cells in TCM 199 or Ham's F-10 and MediCult IVF media. No significant difference in developmental rates was shown between bovine and porcine oviductal epithelial cells but significant difference in co-culture system in comparison between media only system and co-cultures. In conclusions, oviductal epithelial cells, BOEC and POEC, when co-culture with mouse early embryos improved the rates of development, blastocyst and hatching. Therefore, it is suggested that co-culture system using oviductal epithelial cells improve early embryonic developtnent in mouse.

• Animal Bioscience
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• 제35권9호
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• pp.1360-1366
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• 2022

Objective: The present study analyzed the influence of co-transferring embryos with high and low cloning efficiencies produced via somatic cell nuclear transfer (SCNT) on pregnancy outcomes in dogs. Methods: Cloned dogs were produced by SCNT using donor cells derived from a Tibetan Mastiff (TM) and Toy Poodle (TP). The in vivo developmental capacity of cloned embryos was evaluated. The pregnancy and parturition rates were determined following single transfer of 284 fused oocytes into 21 surrogates and co-transfer of 47 fused oocytes into four surrogates. Results: When cloned embryos produced using a single type of donor cell were transferred into surrogates, the pregnancy and live birth rates were significantly higher following transfer of embryos produced using TP donor cells than following transfer of embryos produced using TM donor cells. Next, pregnancy and live birth rates were compared following single and co-transfer of these cloned embryos. The pregnancy and live birth rates were similar upon co-transfer of embryos and single transfer of embryos produced using TP donor cells but were significantly lower upon single transfer of embryos produced using TM donor cells. Furthermore, the parturition rate for TM dogs and the percentage of these dogs that remained alive until weaning was significantly higher upon co-transfer than upon single transfer of embryos. However, there was no difference between the two embryo transfer methods for TP dogs. The mean birth weight of cloned TM dogs was significantly higher upon single transfer than upon co-transfer of embryos. However, the body weight of TM dogs did not significantly differ between the two embryo transfer methods after day 5. Conclusion: For cloned embryos with a lower developmental competence, the parturition rate and percentage of dogs that remain alive until weaning are increased when they are co-transferred with cloned embryos with a greater developmental competence.

• 한국가축번식학회지
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• 제18권3호
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• pp.217-228
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• 1994

These experiments were carried out to establish the optimal condition of electrostimulatin inducing cell fusion and oocyte activation for nuclear transplantation in mouse embryos. Eggs selected for cell fusion or activation by electrostimulation were equilibrated for 5~10 min. in 0.3M sucrose solution and electrostimulated for 60$\mu$sec using 1 pulse of 60, 70, 80, 90 or 100 volts DC with electrodes 0.2 mm apart. Then they were cultured in 20${mu}ell$ dropsof Tyrode's solution. The results of these experiments are as follows : 1. When one pulse of 60, 70, 80, 90 or 100 volts DC for 60$\mu$sec were applied to 2-cell embryos for fusion of blastomeres, fusion rates were 50.0, 81.7, 91.7, 100 and 100%, respectively ; and developmental rates of fused embryos to blastocyst were 76.7 to 81.5%. Higher fusion rates were observed in 90V and 100V. 2. The average cell number in fused embryos developed to blastocyst was about half of the cell number in diploid controls; and the cell number decreased with increasing of voltages. 3. When pulse numbers were increased, fusion rates improved, but developmental rates were not signficiantly different from the group for which the number of pulse was not increased. And the cell number of blastocyst decreased even more. 4. Oocytes aged for 6hrs after ovulation were electrostimulated for oocyte activation by the same method used for cell fusion. Rates of oocyte activated by electrostimulation were 45.3 to 60.4%, and fragmentation rates were 7.5~15.1%. The lysis rates were 17.0~34.0%. The results of these experiments indicate that the optimal condition for achieving cell fusion and activation is 1 pulse, duration 60$\mu$sec in 90 Volt. The results also show that this condition is suitable for nuclear transplantation using mouse eggs.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제26권2호
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• pp.112-119
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• 2015

Objectives : The purpose of this study was to examine the prenatal, perinatal and developmental risk factors of attention-deficit hyperactivity disorder (ADHD), compared to unaffected siblings (SIB), and typically developing children (TC). Methods : Subjects with ADHD, their SIB, and TC were recruited from the child psychiatry outpatient clinic of the Asan Medical Center Children's Hospital. The parents of the children completed questionnaires on perinatal and developmental risk factors. Results : Fifty-eight subjects with ADHD (41 boys, $7.7{\pm}1.3years$), 21 SIB (8 boys, $8.2{\pm}1.8years$), and 22 TC (8 boys, $8.5{\pm}2.1years$) were included. The ADHD group showed higher rates of maternal stress during pregnancy than the SIB group (p=.002), and the ADHD group showed higher rates of familial psychiatric history than the TC (odds ratio, 8.76 ; 95% confidence interval, 1.69 to 45.45). Conclusion : These findings suggest that among perinatal and developmental factors, maternal stress during pregnancy contribute to the development of ADHD. Future prospective studies will be needed in order to determine the causal relationship between perinatal risk factors and development of ADHD.

• 한국수정란이식학회지
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• 제22권4호
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• pp.251-255
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• 2007

This study was carried out to examine on developmental competence of Hanwoo embryos cultured in vitro according to culture conditions and freezing methods. The in vitro developmental competence to blastocyst stage at Day 8 of culture in SOF was significantly (p<0.05) higher than that in CR1aa (30.3% vs. 18.4%). The in vitro developmental rate of morula and blastocysts cultured in group culture was significantly (p<0.05) higher than that in individual culture (41.4% and 36.0% vs. 21.1% and 10.5%, respectively). The cell number of Day 8 blastocysts in group culture was significantly (p<0.05) higher than that in the individual culture ($120.1{\pm}12.8\;vs.\;94.1{\pm}12.1$, respectively). The survival rates of frozen-thawed balstocysts that were exposed in 1.5 M ethylene glycol or 1.5 M ethylene glycol containing 0.1 M sucrose were 77.5% and 78.7%, respectively. The survival rates of blastocysts cultured for 48 h in slow freezing and vitrification was not significantly different (73.3 and 74.0%). In conclusion, in vitro developmental competence of bovine embryos was influenced on the culture medium (SOF) and culture method (Group culture). Survival rate of frozen-thawed of bovine embryos was not influenced on freezing solutions and freezing methods.

• 한국수정란이식학회지
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• 제23권2호
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• pp.77-80
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• 2008

In the present study, effects of concentration of cryoprotectant solutions on the nuclear maturation of vitrified-thawed porcine oocytes were examined. Also, the developmental capacity of vitrified-thawed immature porcine oocytes following ICSI was investigated. Oocytes were cultured in NCSU-23 medium supplemented with 5% FBS at $38^{\circ}C$ in 5% $CO_2$ and air. The in vitro maturation rate of vitrified-thawed oocytes ($24.1{\pm}2.5%$) was lower than that of the control ($46.0{\pm}3.2%$, p<0.05). The in vitro maturation rate of vitrified-thawed oocytes treated with $1.0{\sim}5.0\;ug$ CB + NCSU- 23 medium were $22.2{\pm}3.0%$, $30.7{\pm}3.2$, $46.3{\pm}3.1%$, $38.5{\pm}3.2%$, respectively. The in vitro maturation rate ($46.3{\pm}3.4%$) of the vitrified-thawed oocytes treated with $3.0\;{\mu}g$ CB for 30 min was the highest of all vitrification groups. When the in vitro developmental rates of the vitrified-thawed (with EDS and EDT) oocytes following ICSI were $18.5{\pm}2.5%$, $16.4{\pm}2.1%$, respectively. This results were lower than the control group ($24.0{\pm}2.5%$).