• Clinical and Experimental Reproductive Medicine
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• 제47권2호
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• pp.140-146
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• 2020

Objective: To investigate whether the degree of post-warming embryo or blastocyst development is associated with clinical pregnancy in vitrified embryo or blastocyst transfer cycles. Methods: Ninety-six vitrified cleavage-stage embryos and 58 vitrified blastocyst transfer cycles were selected. All transfer cycles were performed from February 2011 to March 2019, and all vitrified embryos or blastocysts were warmed from 4 PM to 6 PM and then transferred the next morning from 9 AM to 10 AM. The scores of the cleavage-stage embryos and blastocysts were assessed at warming and at transfer using the modified Steer method and the Gardner method, respectively. The mean embryo or blastocyst score, score of the single top-quality embryo or blastocyst, and the difference in the score between warming and transfer were compared between nonpregnant and pregnant women. Results: In the cleavage-stage embryo transfer cycles, both the top-quality embryo score at transfer and the difference in the score between warming and transfer were significantly associated with clinical pregnancy. A top-quality embryo score at transfer of ≥ 60.0 (area under the curve [AUC], 0.673; 95% confidence interval [CI], 0.531-0.815) and a difference in the score between warming and transfer of ≥ 23.0 (AUC, 0.675; 95% CI, 0.514-0.835) were significant predictors of clinical pregnancy. In blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor associated with clinical pregnancy. A top-quality blastocyst score at transfer of ≥ 38.3 was a significant predictor of clinical pregnancy (AUC, 0.666; 95% CI, 0.525-0.807). Conclusion: The top-quality embryo score at transfer and the degree of post-warming embryo development were associated with clinical pregnancy in vitrified cleavage-stage embryo transfer cycles. In vitrified blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor affecting clinical pregnancy.

• 한국수정란이식학회지
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• 제28권3호
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• pp.185-191
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• 2013

The purpose of this study is to improve production efficiency of vitrified-thawed transgenic bovine embryos. Transgenic bovine embryos were produced by injection of FIV-GFP lentiviral vector into perivitelline space of in vitro matured MII stage oocytes, and then in vitro fertilization. EGFP-expressing transgenic bovine blastocysts were cultured in serum-containing and serum-free medium. These blsatocysts were vitrified by pull and cut (PNC) container made with 0.25 cm plastic straw. Results indicate that total developmental rates of normal IVF embryo cultured in serum-containing and-free medium into blastocyst were not significantly different (22.3 vs 21.5%) and those of GFP-expressing transgenic bovine embryo into blastocyst showed no significant difference between serum-containing (13.9%) and-free medium (13.1%). However, developmental rate of GFP transgenic embryo was significantly (P<0.05) lower than its of normal IVF embryos. In additional study, we vitrified GFP transgenic normal bovine blastocysts using PNC vitrification method. Survival rate of vitrified-thawed GFP transgenic blastocyst (23.1%) was significantly (P<0.05) lower than its of normal blastocysts (68.9%). Although, survival rate of vitrified-thawed GFP transgenic blastocyst was lower than its of normal blastocyst, our result may suggested that PNC vitrification method is feasible to cryopreserve transgenic embryos. Our next plan will be the production of GFP express transgenic bovine derived from vitrified-thawed embryos using PNC method.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.76-76
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• 2001

The objective of this study was to optimize the vitrification method of in vitro produced bovine embryos. Thus, in vitro produced embryos at 8 cell, morula and blastocyst stages were vitrified on electron microscope grids (EM grids) or in open pulled straws (OPS) with EG5.5 (5.5 M ethylene glycol, 1.0 M sucrose and 10% FBS in m-DPBS medium) freezing solution and their survival rates after thawing were compared. The embryos on EM grids or in OPS were briefly exposed to EG5.5 freezing solution and plunged directly into liquid nitrogen within 30 to 35 sec. Post-thawed embryos were serially diluted in 0.5, 0.25 and 0.125 M sucrose in m-DPBS, each for 1 min, and then cultured in CRI aa medium supplemented with 10% FBS. Embryonic survival rate was assessed as re-expanded and hatched rates of those embryos after warming. The rates of re-expansion embryos did not significantly different between EM grid (8 cell: 42.10%, morula: 66.66% and blastocyst: 77.08%) and OPS (8 cell: 47.36%, morula: 61.90% and blastocyst: 83.33%) methods. In addition, the hatched rates in EM grid (8 cell: 31.57%, morula: 57.14% and blastocyst: 72.91%) were similar to those in OPS (8 cell. 34.21%, morula: 50.00% and Blastocyst: 77.08%). Interestingly, even at the same blastocyst stage, the in vitro survival of day 7 embryos (EM grid: 79.48 and OPS: 87.18%) was higher than those of day 8 embryos (EM grid: 72.10 and OPS: 82.06%). The total cell number of blastocyst developed in vitro after vitrification was examined with Hoechst 33342 staining to compare the embryo quality among different treatment groups. The total cell number of blastocyst was not significantly different between vitrified groups (EM grid: 162.4$\pm$8.0 and OPS: 158.4$\pm$7.1) and unvitrified control (168.0$\pm$5.6). These results indicate that both vitrification containers can provide the high rate of embryo survival. Moreover, the OPS container may not need a cap to protect the container from floating after immersion in L$N_2$. Therefore, this study suggest that bovine embryos can be cryopreserved easily, effectively and successfully by vitrification method using EM grid or OPS with EG5.5 freezing solution. In the future, the Pregnancy rate would be investigated after transfer of our vitrified embryos into the appropriated recipients.

• 한국수정란이식학회지
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• 제9권2호
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• pp.173-180
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• 1994

The present experirnents on cryopreservation were carried out to investigate effect of solution toxicity, equilibration time and cell stages on the post-thaw survival of mouse morulae and blastocyst embryos cryopreserved by vitrification in EFS solution. The mouse embryos were exposed to the EFS solution in one step at room temperature, kept in the EFS solution during different period for toxicity test, vitrified in liquid nitrogen and thawed rapidly. After the mouse morulae embryos were exposed to EFS solution for 2 and 5 ruin. at room temperature and then they were washed in 0.5 M sucrose solution and basal mediurn(D-PBS + 10% FCS), they were cultured to examined cryoprotectant toxicity induced injury during exposure, most of embryos developed to expanded blastocysts(100 and 90.0%). However, when the exposure time was extended to 10 and 20 min, these development rates dropped dramatically in 10 ruin. (75.0%) and 20 ruin. (4.5%), respectively. When the compacted morulae were vitrified in EFS solution after equilibration for 2 and 5 min, the embryos have developed to normal blastocyst following thawing, washing and culture processes was 89.3 and 89.6%. However, when the exposure time was expanded to 10 ruin, this survival rate dropped to 68.8%. When the blastocyst were vitrified in EFS solution after equilibration for 2, 5 and 10 minutes, the survival rate of embryos which developed to normal blastocyst following thawing and culture processing were 58.5, 46.7 and 22.4%, respectively. The optimal time of equilibration of mouse morula and blastocysts in EFS solution seemed o be 2 and 5 ruin.

• 한국동물생명공학회지
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• 제36권4호
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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.

• Reproductive and Developmental Biology
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• 제31권4호
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• pp.235-240
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• 2007

This study was conducted to examine the viability of Korean native striped cattle (Bos namadicus Falconer, Chikso) clone embryos after embryo transfer. Chikso somatic cell nuclear transfer (SCNT) embryos were produced by fusion of ear skin cells derived from a female Chikso with enucleated oocytes matured in vitro for 18-24 hr. After in vitro culture of SCNT embryos for 7 to 8 days, fresh or vitrified blastocysts derived from SCNT were transferred into a uterine horn of recipient cows. Fifteen of total 43 recipients were pregnant at Day 50 and 4 recipients were maintained to term. Three IVF-derived calves and 1 clone Chikso calf were born. Pregnancy rate was higher when fresh embryos were transferred to recipients compared to vitrified embryos, but development to term was not different between both groups. The clone Chikso calf died at 5 days after birth due to the fullness of amniotic fluid in rumen and the infection of umbilical cord. The result of the present study shows that clone Chikso calf can produced from the embryo transfer of SCNT embryos, however, solution of abortion problem is necessary to improve the cloning efficiency.

• 한국가축번식학회지
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• 제22권4호
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• pp.307-317
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• 1998

본 연구는 체외수정란올 손쉽고, 간편하게 장기간 동결보존 할 수 있는 초자화 동결방법을 검토하기 위하여, 초자화 동결 보존용액의 구성성분과 dextrose가 우 체외수정란의 동결보존 융해후 체외 발육율과 생존성에 미치는 영향에 대하여 조사하였다. 1. ETP 용액에서 초자화 동결 시킨후 융해하여 24∼48시간 체외배양하여 얻은 생존율에 있어서 체외배양일에 따라 생산된 배반포 및 확장배반포기 수정란의 체외생존율은 6일, 7일, 8일 및 9일에 각각 11.9% 19.8%, 23.4% 및 15.3%로서 처리구간에 커다란 차이는 없었으나, 발육단계별 성적은 배반포기가 15.2% 로서 확장배반포기의 23.3% 보다 유의하게 낮았다 (P＜0.05). 2. ETP 초자화 동결 보존액에 당의 청가 (0.375M dextrose)가 초자화 동결 융해후 생존성에 미치는 효과을 검토한 결과, 체외배양일에 따른 동결 융해후 생존성은 7일에 생산된 수정란이 54.5%로서 여타구 (6일, 34.6% ; 8일, 37.9% ; 9일, 13.0%)보다 높은 성적을 얻었으며, 발육단계별 동결융해후 생존성에서는 확장배반포기 수정란이 45.8%로서 배반포기 수정란의 25.0% 보다 통계적으로 유의하게 높아 (P＜0.05), 실험 1의 결과와 유사한 경향을 보였으며, 당을 첨가할 경우 다소 높은 생존율을 나타냈다. 3. ETP 초자화 동결용액에서 PVP 농도가 생존성에 미치는 영향을 검토한 결과, 12% PVP 첨가구(20.0%) 와 20% PVP 첨가구 (19.8%)에서 동결 융해하여 24∼48 시간 체외배양한 후 생존성에는 커다란 차이가 인정되지 않았으며, 발육단계별 성적에서도 차이가 인정되지 않았다. 4. GESD 동결용액을 이용한 초자화 동결에 있어서 7일∼9일 사이에 생산된 체외수정란을 동결융해하여 24∼48시간 체외배양하여 얻은 생존율은 8일째에 생산된 수정란의 동결 융해후 생존성이 94.6%로서 7일 (71.4%)와 9일 (40.5%)에 생산된 수정란보다 유의하게 높은 성척을 얻었다(P＜0.05). 한편 초자화 동결 수정란을 융해하여 체외배양시킨 후 hatching 까지 배양된 체외 발육율은 8일째에 생산된 수정란이 35.1%로서 7일의 28.6% 와 9일의 16.2% 보다 우수한 결과를 얻어 24∼48시간 체외배양 성적과 동일한 경향을 보였다. 5. GETP 동결용액을 이용한 초자화 동결에 있어서 체외배양일 (7일∼9일)에 따라 생산된 수정란을 동결융해하여 일정시간 동안 체외배양시킨 후 생존성과 hatching 배반포기까지의 체외발육율은 배양일에 따라 생산된 수정란들간에 커다란 차이가 포기가 37.0%로서 배반포기 인정되지 않았으나 (P＞0.05), 발육단계별 성적에서는 확장배반수정란의 9.6% 보다 유의하게 높은 성적을 얻었다(P＜0.05).

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2005년도 제5회 발생공학 국제심포지엄 및 학술대회
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• pp.146-146
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• 2005

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2005년도 제5회 발생공학 국제심포지엄 및 학술대회
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• pp.146-146
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• 2005

• 한국동물생명공학회지
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• 제37권4호
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• pp.231-238
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• 2022

Reactive oxygen species (ROS) production and F-actin cytoskeleton dynamics play important roles in the survival rate of blastocysts after the vitrified-warming process. However, the protective effects of Mito-TEMPO against cryo-injury and viability through F-actin aggregation and mitochondrial-specific ROS production in vitrificated-warmed bovine embryos have not been investigated. The aims of the present study were to: (1) determine the effects of Mito-TEMPO on embryonic developmental competence and quality by F-actin stabilization during in vitro culturing (IVC), and (2) confirm the effects of Mito-TEMPO through F-actin structure on the cryotolerance of vitrification-warming in Mito-TEMPO exposed in vitro production (IVP) of bovine blastocysts. Bovine zygotes were cultured with 0.1 μM Mito-TEMPO treatment for 2 days of IVC. Mito-TEMPO (0.1 μM) exposed bovine embryos slightly improved in blastocyst developmental rates compared to the non-treated group. Moreover, the viability of vitrified-warmed blastocysts from Mito-TEMPO treated embryos significantly increased (p < 0.05, non-treated group: 66.7 ± 3.2% vs Mito-TEMPO treated group: 79.2 ± 5.9%; re-expanded at 24 hours). Mito-TEMPO exposed embryos strengthened the F-actin structure and arrangement in the blastocyst after vitrification-warming. Furthermore, the addition of Mito-TEMPO into the IVC medium enhanced embryonic survival and quality through F-actin stabilization after the vitrification-warming procedure. Overall, our results suggest that supplementing the culture with 0.1 μM Mito-TEMPO improves the embryonic quality and cryo-survival of IVP bovine blastocysts.