• Journal of Embryo Transfer
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• v.10 no.1
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• pp.83-90
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• 1995

Production of calves after transfer of nuclear transplant embryos is the latest technology to be applied in commercial livestock breeding. The objective of this study was to establish an efficient procedure to produce offsprings from nuclear transplant embryos. The fusion rates (72.7% vs. 80.8%), cleavage rates (62.5% vs. 71.4%) and rates of development in vitro (12.0% vs. 15.2%) of nuclear transplant embryos were not significantly different between 30 and 40h maturation age of cytoplast. The in vivo and in vitro-derived embryos as nuclei donor were used in this system of bovine nuclear transplantation. Fusion rates of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (73.0 and 79.2%, respectively). The percentage of embryos reaching the morulae or blastocysts were 21.8% for in vivo-derived embryos and 11.9% for in vitro-derived embryos (p<0.01). Pregnancy rates after embryo transfer of nuclear transplant embryos were not significantly different between in vivo and in vitro-derived embryos (45.9 and 40.5%, respectively). However, calving rates after embryo transfer of nuclear transplant embryos were significantly higher in the in vivo-derived embryos than in vitro (p<0.01). Further research for age of cytoplast and use of in vitro-derived embryos as nuclei donor is required in this system. In conclusion, these results clearly show that the use of in vitro-derived oocytes as recipient cytoplast can improve the nuclear transplant system for genetic progress in cattle.

• Journal of Embryo Transfer
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• v.12 no.1
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• pp.37-48
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• 1997

I. The Factors Influencing In Vivo Embryo Production by Condition of Superovulation Treatment These studies were carried out to establish an effective and practical system for comrnercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on superovulation treatment in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors.The results obtained from the studies on the factors influencing in vivo embryo production by superovulation treatment were as follows : FSH-P had a significiant advantage(83.0%) over SUPER-OV in the percentage of fertilized embryos(P<0.01). No difference was found loetween FSH-P and SUPER-OV in the percentage of transferable and freezable embryos.2. The response of superovulation by SUPER-OV was greater than that of FSH-P The donors having 8~9 and more than 10 of corpora lutea(CL) derived by FSH-P were 40.0%(most frequent) and 33%, respectively. The donors having more than 12 and 10 CL derived by SUPER -OV were 33.3% (most frequent) and 56.6%, respectively.3. Embryo production after treatment of repeated superovulation was remarkablely decreased at 3rd time by FSH-P but did not differ among 1, 2 and 3rd times by SUPER-OV. Embryo production on intervals of repeated superovulation was significantly different for the number and percentage of fertilized, transferable and free-zable' embryos in FSH-P (P<0.01) and rernarkablely decreased in repeated superovulation of 81~120 interval days. The SUPER-OV showed no differences in interval days of repeated superovulation and was found better than FSH-P in the response of repeated superovulation. (Key words : in Vivo embryo, superovulation, FSH -P, SUPER-OV)

• Animal Bioscience
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• v.35 no.2
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• pp.177-183
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• 2022

Objective: The present study evaluated the efficiency of embryo development and pregnancy of somatic cell nuclear transfer (SCNT) embryos using different source-matured oocytes in Camelus dromedarius. Methods: Camelus dromedarius embryos were produced by SCNT using in vivo- and in vitro- matured oocytes. In vitro embryo developmental capacity of reconstructed embryos was evaluated. To confirm the efficiency of pregnancy and live birth rates, a total of 72 blastocysts using in vitro- matured oocytes transferred into 45 surrogates and 95 blastocysts using in vivo- matured oocytes were transferred into 62 surrogates by transvaginal method. Results: The collected oocytes derived from ovum pick up showed higher maturation potential into metaphase II oocytes than oocytes from the slaughterhouse. The competence of cleavage, and blastocyst were also significantly higher in in vivo- matured oocytes than in vitro- matured oocytes. After embryo transfer, 11 pregnant and 10 live births were confirmed in in vivo- matured oocytes group, and 2 pregnant and 1 live birth were confirmed in in vitro- matured oocytes group. Furthermore, blastocysts produced by in vivo-matured oocytes resulted in significantly higher early pregnancy and live birth rates than in vitro-matured oocytes. Conclusion: In this study, SCNT embryos using in vivo- and in vitro-matured camel oocytes were successfully developed, and pregnancy was established in recipient camels. We also confirmed that in vivo-matured oocytes improved the development of embryos and the pregnancy capacity using the blastocyst embryo transfer method.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.69-74
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• 2016

Skin-derived precursors (SKPs) have potential to differentiate to various cell types including osteoblasts, adipocytes and neurons. SKPs are a candidate for cell-based therapy since they are easily accessible and have multipotency. Most mammalian cells are exposed to a low oxygen environment with 1 to 5% $O_2$ concentration in vivo, while 21% $O_2$ concentration is common in in vitro culture. The difference between in vitro and in vivo $O_2$ concentration may affect to the behavior of cultured cells. In this report, we investigated the effect of hypoxic condition on stemness and proliferation of SKPs. The results indicated that SKPs exposed to hypoxic condition for 5 days showed no change in proliferation. In terms of mRNA expression, hypoxia maintained expression of stemness markers; whereas, oncogenes, such as Klf4 and c-Myc, were downregulated, and the expression of Nestin, related to cancer migration, was also downregulated. Thus, SKPs cultured in hypoxia may reduce the risk of cancer in SKP cell-based therapy.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.779-791
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• 2023

This study aimed to assess the effects of embryonic developmental stage, quality grade, and fresh or frozen/thawed conditions on the pregnancy rate and sex ratio of live offspring in Hanwoo (Bos taurus coreanae) cows. The quality and developmental stage of in vivo-derived (IVD) transferred embryos were evaluated using the standard criteria of the International Embryo Technology Society. The recipient cows were synchronized using conventional (estradiol benzoate and progesterone) protocols before embryo transfer. Embryos were transferred to 297 cows, and pregnancy was monitored for 60-70 days after embryo transfer. The pregnancy rates of fresh and frozen/thawed embryos were 56.90% and 52.49%, respectively. Pregnancy rates varied according to embryo quality (56.18% for grade 1 vs. 36.67% for grade 2). Pregnancy rates also varied by developmental stage and cryopreservation (67.86% vs. 63.49% for stage 4-1, 64.00% vs. 54.72% for 5-1, and 50.00% vs. 47.83% for 6-1, in fresh embryos vs. frozen/thawed embryos, respectively). For stage 7-1, the pregnancy rates were 72.73% for fresh embryos and 20.00% for frozen/thawed embryos. In 66 fresh embryos, the sex ratio of live offspring was 5:5, whereas it was 4(female):6(male) for frozen/thawed embryos among the 95 frozen/thawed embryos. The miscarriage rate was approximately 3% higher for frozen/thawed embryos than for fresh embryos (18.1% for fresh vs. 21.1% for frozen). Seasonal fertility rates were 33.3% in spring, 55.67% in summer, 52.8% in autumn, 60.0% in winter. The following male-to-female ratios were observed in different seasons: 6.7:3.3 in spring, 4.0:6.0 in summer, 5.5:4.5 in autumn, and 3.3:6.7 in winter. The current data revealed no significant differences in pregnancy rates between fresh and frozen/thawed IVD embryos. However, there was a lower pregnancy rate with advanced-stage frozen/thawed embryos (stage 7-1). The current study provides comprehensive results for the better optimization of embryo transfer in Hanwoo cattle to obtain the desired fertility rate, pregnancy rate, and sex ratio of calves. These results provide important insights into the factors that influence the viability and success of IVD embryo transfer in Hanwoo cows and may have practical applications for improving breeding programs and reducing production costs.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.269-275
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• 2011

The objective of this study was to develop a rapid and reliable PCR method for sexing of morula or blastocyst stage bovine embryo. BOV97M and bovine 1.715 satellite DNA sequences were selected for amplification of male and bovine specific DNA, respectively. But the unbalanced number of copies of these two repetitive sequences required some modification of PCR method. Karyotyping of blastomeres were carried for the confirmation of sex determination in bovine embryos. The coincidence rate of sex between biopsied-single blastomere and matched blastocyst was 80.0%. When in vivo- and in vitro- derived embryos were compared, 61.8% and 56.7% were male in in vitro- and in vivo-derived embryos, respectively. In vivo-derived embryos showed better hatching rate than in vitro-derived embryos following biopsy of blastomeres. In conclusion, rapid and effective PCR could be applied to sexing of bovine preimplantation embryos using single blastomere. The sensitivity of this assay may eliminate the need for biopsy of more than one nucleated blastomere and reduce trauma to the embryos derived from biopsy procedure.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.189-193
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• 2010

We investigated the cleavage rate and blastocyst yield for each culture condition to enhance tolerance of cryo-preservation of bovine IVF embryo with relatively lower cryo-tolerance compared to in vivo embryo. The cleavage rate and blastocysts yield for CR1aa, IVMD, IVD, CR1aa+10% FBS were 73.2, 69.3, 72.8, 68.5% and 44.1, 30.8, 33.3, 48.0%, respectively. The values did not differ among each treatments without serum. For embryo vitrification, In vivo and In vitro blastocysts were exposed to VS1(10% glycerin, 0.1 M glucose, 0.1 M sucrose, PEG 1%) for 5 min, and VS2 (10% glycerin, 10% EG, 0.2 M glucose, 0.2 M sucrose, PEG 2%) for 5 min and then VS3 (10% glycerin, 30% EG, 0.3 M glucose, 0.3 M sucrose, PEG 3%) for 1 min. The exposed embryos were then loaded into the 0.25 ml plastic straws and then plunged into liquid nitrogen. The straws were held for period of 1 to 2 weeks before thawing. In embryo viability, no differences in blastocyst re-expansion rates were found between in vivo and in vitro embryos. whereas expansion-BL rates was significantly higher for in vivo-derived embryos (72.7%) when compared to in vitro-derived embryos (51.4%), respectively (P<0.05). In conclusion, our results indicate that combined use of CRIaa culture medium with vitrification might enhance tolerance of cryopreservation for bovine IVF embryo production.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2001.10a
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• pp.25-34
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• 2001

The Committee has, for the 9th consecutive year, compiled statistics of embryos collected and transferred worldwide. Geographically, all regions have participated in the survey; however, there are still some places where it has been impossible to retrieve such data (particularly in Asia). The statistics, therefore, are partially underestimated. By contrast, in other areas, the system has proven to be more efficient than before, particularly in North and South America. This has resulted in the present report, which gives a somewhat more satisfactory picture of the current situation of the ET industry. For the second year, it has also been possible to collect data for several species other than cattle. In cattle, the number of in vivo-derived embryos collected and transferred has once again increased with more than half a million embryos trans-ferred in 1999(520,712), a new record. The number of bovine in vitro-produced embryos has remained stable this year as compared with the previous year(approximately 30,000 embryos transferred). However, there are still teams that have not Yet reported their data. More than 10,000 embryos in each of the ovine and caprine species and close to 2,000 cervid embryos were reported transferred in 1999. Some 500 embryos of the equine species and a few thousand in the porcine and rabbit species have also been transferred in 1999. It is concluded that the ET industry continues to be very active, and, in many species, it encompasses a larger segment of the livestock population overall, which is to the farmer s benefit.

• Journal of Embryo Transfer
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• v.26 no.3
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• pp.195-199
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• 2011

The objective of this study was to evaluate the efficiency of the conventional slow freezing and vitrification methods for cryopreserving in vivo and in vitro-produced bovine embryos. Morphology of post-thawed embryos was evaluated and normal embryos were used for successive culture for 72 h. In experiment I, In embryo viability, There was no significant differences in blastocyst re-expansion rates were found between in vivo and in vitro embryos(89.6% vs. 81.5%). whereas hatched-BL and total cell number rates was significantly higher (p<0.05) for in vivo-derived embryos (76.9%, 136${\pm}$3.6 vs. 43.4%, 107${\pm}$3.8). In experiment II, There was no significant differences in blastocyst re-expansion and Expansion-BL rates were found between in slow freezing and vitrification methods (91.3% vs. 85.7% and 71.4% vs. 75.0%, respectively). in conclusion, These results suggested that the field application for bovine embryo transfer is in part supported by improvements of technologies in embryo conventional slow freezing and vitrification cryopreservation.

• Clinical and Experimental Reproductive Medicine
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• v.41 no.1
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• pp.1-8
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• 2014

Objective: Estrogen related receptor ${\beta}$ (Esrrb) is a member of the orphan nuclear receptors and may regulate the expression of pluripotencyrelated genes, such as Oct4 and Nanog. Therefore, in the present study, we have developed a method for delivering exogenous ESRRB recombinant protein into embryos by using cell-penetrating peptide (CPP) conjugation and have analyzed their effect on embryonic development. Methods: Mouse oocytes and embryos were obtained from superovulated mice. The expression of Oct4 mRNA and the cell number of inner cell mass (ICM) in the in vitro-derived and in vivo-derived blastocysts were first analyzed by real time-reverse transcription-polymerase chain reaction and differential staining. Then 8-cell embryos were cultured in KSOM media with or without $2{\mu}g/mL$ CPP-ESRRB protein for 24 to 48 hours, followed by checking their integration into embryos during in vitro culture by Western blot and immunocytochemistry. Results: Expression of Oct4 and the cell number of ICM were lower in the in vitro-derived blastocysts than in the in vivo-derived ones (p<0.05). In the blastocysts derived from the CPP-ESRRB-treated group, expression of Oct4 was greater than in the non-treated groups (p<0.05). Although no difference in embryonic development was observed between the treated and non-treated groups, the cell number of ICM was greater in the CPP-ESRRB-treated group. Conclusion: Treatment of CPP-ESRRB during cultivation could increase embryos' expression of Oct4 and the formation rate of the ICM in the blastocyst. Additionally, an exogenous delivery system of CPP-conjugated protein would be a useful tool for improving embryo culture systems.