• Clinical and Experimental Reproductive Medicine
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• 제44권2호
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• pp.79-84
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• 2017

Objective: Optimizing in vitro maturation (IVM) media to achieve better outcomes has been a matter of interest in recent years. The aim of this prospective clinical trial was to investigate the effects of different media on the IVM outcomes of immature oocytes at the germinal vesicle (GV) stage. Methods: A total of 400 immature oocytes at the GV stage with normal morphology were retrieved from 320 infertile women aged $31{\pm}4.63years$ during stimulated intracytoplasmic sperm injection (ICSI) cycles. They were divided into groups of homemade IVM medium (I, n = 100), cleavage medium (II, n = 100), blastocyst medium (III, n = 100), and Sage IVM medium (IV, n = 100) and cultured for 24 to 48 hours at $37^{\circ}C$. ICSI was performed, and the rates of fertilization and embryo formation were compared across the four groups. Results: In the 400 retrieved GV oocytes, the total maturation rates showed significant differences in groups I to IV (55%, 53%, 78%, and 68%, respectively, p<0.001). However, there were no significant differences in the fertilization, embryo formation, or arrest rates of metaphase II oocytes across these groups. In all groups, GV maturation was mostly completed after 24 hours, with fewer oocytes requiring 48 hours to mature (p<0.01). Moreover, the rate of high-quality embryos was higher in group IV than in the other groups (p=0.01). Conclusion: The quality of the IVM medium was found to affect clinical IVM outcomes. Additionally, blastocyst medium may be a good choice in IVM/ICSI cycles as an alternative IVM medium.

• 한국수정란이식학회지
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• 제31권2호
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• pp.131-136
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• 2016

Since the first success of animal cloning, somatic cell nuclear transfer presented various ideas in many research areas such as regenerative medicine. However, SCNT embryos has poor survival rate. Therefore, numerous researches carried out to enhance the developmental capability of porcine nuclear transfer embryos. Cytochalasin B, demecolcine, latrunculin A, cycloheximide and 6-dimethylaminopurine are efficient chemicals treated in post-activation procedure to increase the efficiency of SCNT. This review study is aim to investigate the effects of these chemicals applied to post-activation in porcine SCNT. Cytochalasin B, demecolcine, latrunculin A are cytoskeletal manuplators inhibit extrusion of pseudo-polar body. Cytochalasin B and demecolcine showed considerably higher blastocyst formation proportion (26-28%) compared to when they are not treated (16%). And when latrunculin A was treated for postactivation, blastocyst formation proportion was increased in SCNT embryos exposed to LA (38%) than those in control (14%). On the other hand, cycloheximide and 6-dimethylaminopurine are protein synthesis and kinase inhibitors. And they help to maintain $Ca^{2+}$ fluctuation in oocytes. Cleavage and blastocyst rates of NT embryos were increased when they were exposed to CHX (16.9% and 5.4% with no CHX).And 6-DMAP also showed higher blastocyst formation (21.5% compared to 15.7%, control). Although all these chemicals have different mechanisms, they showed developmental competence enhancement in NT embryos. However, there are only few studies comparing each chemical's post-activation effect. Therefore, further research and study should be conducted to find optimal chemical for improving the efficiency of SCNT.

• 한국수정란이식학회지
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• 제31권3호
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• pp.179-183
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• 2016

Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell-derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.

• 농업과학연구
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• 제45권3호
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• pp.493-498
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• 2018

There has been widespread warming and a general increase in summer temperatures over the Korean peninsula ($0.5^{\circ}C$/10 years from 2001 to 2010). South Korea is transforming into a subtropical region, and the productivity of livestock is affected by the climatic changes. In this study, we investigated whether the summer heat waves affect the developmental competency of Korean native cattle (Hanwoo), a taurine type of cattle with a small portion of indicine varieties. We collected oocytes during the summer (heat stress, HS) and autumn (non-HS condition) and examined the developmental competencies including in vitro maturation and preimplantation embryo development. No significant differences were observed between the HS and non-HS oocytes in nuclear maturation (extrusion of the polar body); however, the cleavage and blastocyst rates were significantly lower in the HS group than those in the non-HS group. The lower developmental competence of the HS oocytes compared to the non-HS is, in part, due to insufficient cytoplasmic maturation because of a higher production of Reactive oxygen species (ROS) levels as well as peri/cortical distributed mitochondria in the HS oocytes after in vitro maturation. Next, we examined the ROS and mitochondria distribution and found a significant increase in the levels of ROS in the HS oocytes and a polarized distribution (pericortical cytoplasm) of mitochondria in the HS oocytes. In summary, impaired cytoplasmic maturation of oocytes from exposure to HS affects the preimplantation embryo development by dysfunction of mitochondria. To improve reproductive performance, embryo transfer using cryopreserved embryos/oocytes is recommended in the hot summer season of South Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1095-1101
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• 2016

Ginsenoside Rg1 is a natural compound with various efficacies and functions. It has beneficial effects on aging, diabetes, and immunity, as well as antioxidant and proliferative functions. However, its effect on porcine embryo development remains unknown. We investigated the effect of ginsenoside Rg1 on the in vitro development of preimplantation porcine embryos after parthenogenetic activation in high-oxygen conditions. Ginsenoside treatment did not affect cleavage or blastocyst formation rates, but did increase the total cell number and reduced the rate of apoptosis. In addition, it had no effect on the expression of four apoptosis-related genes (Bcl-2 homologous antagonist/killer, B-cell lymphoma-extra large, Caspase 3, and tumor protein p53) or two metabolism-related genes (mechanistic target of rapamycin, carnitine palmitoyltransferase 1B), but increased the expression of Glucose transporter 1 (GLUT1), indicating that it may increase glucose uptake. In summary, treatment with the appropriate concentration of ginsenoside Rg1 ($20{\mu}g/mL$) can increase glucose uptake, thereby improving the quality of embryos grown in high-oxygen conditions.

• 한국수정란이식학회지
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• 제26권3호
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• pp.171-180
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• 2011

In this study I report that in vitro development rates of bovine nuclear transfer embryos activated either with boar sperm cytosolic factor (SCF) or with ionomycin followed by cycloheximide (CHX) and subsequent in vivo developmental rates after embryo transfer are related to blastocyst quality as evaluated by apoptosis analysis. SCF was extracted from porcine semen then purified for post-activation injection after nuclear transfer. The optimal timing for SCF injection was determined to be at least 22 h post-IVM for parthenogenetic activation of bovine oocyies. A total of 364 oocytes were successfully enucleated and 268 (73.6%) fused and were injected with SCF. The survival rate of fused and injected embryos was 109/113 (96.5%) after 2 h. The cleavage rates of nuclear transfer embryos after 3 d of culture in the ionomycin/CHX treated group were significantly higher than those of the SCF-activated group (93.3% vs 81.7%, p<0.01, respectively). However, at 7 d and 9 d there was no significant difference between the total developmental rates to blastocyst for either treatment group. Total blastocyst cell numbers were also not significantly different between the two activation treatments (ionomycin/CHX: 149.5${\pm}$7.7 vs. SCF: 139.3${\pm}$4.4 cells). In contrast, the apoptotic levels in the SCF blastocysts were higher than those produced after the chemical treatment (28.2${\pm}$5.1% vs. 8.8${\pm}$0.6%, respectively). A total of 18 expanded or hatching blastocysts was transferred to nine synchronized recipients in each activation group; 5/9 (55.5%) and 2/9 (22.2%) were pregnant at 40 d in the ionomycin/CHX treatment and SCF activated group, respectively. However, only one went to term in the ionomycin/CHX treatment while none of the pregnancies from the SCF group were maintained by 90 d. In conclusion, these results suggest that SCF derived from different species is a limited activator to be used for activation after bovine nuclear transfer in lieu of a chemical activation protocol.

• 한국수정란이식학회지
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• 제17권1호
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• pp.13-21
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• 2002

Intracytoplasmic Sperm Injection (ICSI) has been widely used fur both human infertility and basic research. However, the high incidence of chromosomal abnormality is severe problem in cattle. Various oocyte activation stimuli, therefore, were compared by assessment of developmental capacity and chromosome analysis. Motile sperm selected by Percoll-density gradient were treated with 5 mM dithiothreitol (DTT) and injected into an oocyte matured fur 24 h. Eggs were then allocated into 5 treatment groups. Group 1 (control), sperm injection was performed without any further activation stimuli to the oocytes. Group 2 (handled control), sham injection was performed without sperm. In Group 3, oocytes exposed to 5 (M ionomycin for 5 min at 39(C. Group 4. ionomycine + 1.9 mM demethylaminopurine (DMAP, 3 h) and Group 5, ionomycine + 3 h culture in Ml99 + DMAP. Cleavage and the later development rate in Groups 1, 2 and 3 were significantly (P<0.05) lower than those in Groups 4 and 5. The incidence of chromosomal abnormality in the embryos treated directly with DMAP after ionomycine was relatively higher than in the embryo of Group 3 h, delayed DMAP treatment. From this results DMAP caused to be arrested the release of the 2nd polar body, resulting in changes of chromosomal pattern. Therefore, the time interval between ionomycin and DMAP is a crucial role in bovine ICSI.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1117-1123
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• 2009

This study investigated the effects of IGF-I and EGF on the development of blastocysts or hatched blastocysts during the in vitro culture of embryos from immature porcine oocytes. After the in vitro maturation and fertilization of cumulus-oocyte complexes (COCs) and their culture in vitro in PZM3 medium, we examined the embryo development rate for 168 h. When different concentrations of IGF-I (0, 1, 10, 20 ng/ml) were supplemented to fertilized porcine embryos in vitro, there were no significant differences in cleavage rate, blastocyst development rate or blastocyst hatching rate among the treated groups. On the other hand, when different concentrations of EGF (0, 1, 10, 20 ng/ml) were supplemented to the in vitro culture medium, blastocyst development rate was highest in the group in which EGF was not supplemented and, specifically, it was higher than in the 20 ng/ml treatment group (p<0.05). When 10 ng/ml IGF-I and 1 ng/ml EGF were supplemented separately or simultaneously, there were no significant differences among the treated groups in blastocyst hatching rate and the number of cells in each condition. This study demonstrated that the addition of IGF-I and EGF into PZM3 medium did not enhance development of the blastocyst stage and total cell number in blastocysts.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 1998년도 제4차 학술발표대회 및 정기총회
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• pp.12-18
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• 1998

Tremendous progress has been made over the past quarter-century studying the genetics of gametogenesis and the resulting gametes and embryos. Studies merging molecular techniques and conventional cytogenetics are now beginning to bridge the gap between what we have learned about the meiotic process in males and females and what we know of the mitotic chromosomes of zygotes. Numerical abnormalities in sperm, oocytes and embryo can now diagnosed by fluorescence in situ hybridization (FISH). "At risk" couples can, therefore, have only unaffected embryos replaced in the sterus and avoid the possibility of terminating a pregnancy that might only be diagnosed as affected later gestation. Single-cell genetic analysis has also provided powerful tools for studying genetic defects arising during early human development. Recent studies of sperms, oocytes and cleavage-stage human embryos have revealed an unexpectedly high incidence. These genetic abnormalities are likely to contribute to early pregnancy loss and have important implications for improving pregnancy rates in infertile couples by assisted reproduction. The widespread use of preimplantation genetic diagnosis (PGD) awaits further documentatio of safety and accuracy. Other issues also must be addressed. First, the ethical issues regarding germ cell and embryo screening must be addressed including what diseases are serious enough to warrant the procedure. Another concern is the use of this technology for non-genetic disorders such as gender selection. Finally, the experimental nature of these procedure must continually be discussed with patients, and long-term follow-up studies must be undertaken. Development of more accurate and less expensive assays coupled with improved assisted reproductive technology success rates may make PGD a more widely use clinical tool. The future awaits these development.velopment.

• Reproductive and Developmental Biology
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• 제30권1호
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• pp.21-26
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• 2006

본 연구는 체외성숙 배지에 첨가하는 PVP의 농도, EGF, cysteine 및 PVP의 단독 또는 혼합첨가가 한우 체외수정란의 체외발생에 미치는 영향을 검토하였다. 체외성숙 배지에 PVP의 첨가농도$(0.1{\sim}3.0%)$에 따른 분할율은 차이가 없었으나, 배반포 발달율은 0.5% PVP 첨가군이 가장 높았다(P<0.05). PVP, EGF 및 cysteine의 단독 및 혼합 첨가에 따른 분할율은 cysteine 단독첨가군이 높았으나(P<0.05), 배반포 발달율은 차이가 없었다. Inner cell mass 수는 대조군과 cysteine 첨가군이 PVP 첨가군에 비하여 유의하게 높았고(P<0.05), 총 세포수도 cysteine 첨가군에서 가장 높았다. 수정란이식 결과는 대조군, EGF, cysteine 및 EGF+cysteine 군의 임신율은 $46.1{\sim}63.6%$로서 비슷하였으나, PVP 첨가군은 10%로서 다른 군에 비하여 유의하게 낮았다(P<0.05). 본 연구 결과는 체외성숙 배지에 PVP의 첨가로 배 발생은 가능하지만, 세포의 품질에는 악영향을 미치는 것을 보여준다.