• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
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• pp.6-8
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• 2006

• 한국수정란이식학회지
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• 제9권2호
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• pp.167-172
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• 1994

This experiment was arried out to investigate the development of ea4y rabbit embryos in vivo. Twenty-six New Zealand White does were superovulated by treatment with PMSG(Intervet Co; I. M single injection, 150. U./rabbit) followed 3 day later by simultaneous I.V injection of 100 I.U HCG (Intervet Co, )and natural service with fertile male. All of does was killed at the specific times (24, 27, 30, 36, 42, 50 and 93 h post-hCG) to find out the early embryonic development in vivo respectively. Embryos at the specified stages of development were obtained at the following times after injection of hCG; one-ceH at 24 h, two-cell at 24~27h, four-cell at 27~36 h, morulae at 50 h and early blasto-cyst at 93 h and expanded or hatching blastocyst at 144 h. Number of embryos recovered per rabbit superovulated was 26.1 and average of recovery rate was 83.7%. The results suggest that superovulation was efficient for the increase of embryo number in rabbits, and as shown in results, asynchronous cleavage was prevalent among the recovered embryos.

• 한국수정란이식학회지
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• 제25권4호
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• pp.221-227
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• 2010

Early cleavage is a reliable prognostic tool for successful embryo transfer in assisted reproduction because early cleaved embryo show better pregnancy rate after transfer. There for, preparation of good embryo recipient is important factor to optimize efficiency of pig cloning. The present study was performed to evaluate the effect of early cleavage on the in vivo development of cloned embryos and to analyze breed, parity and estrous synchrony to optimize recipient for pig cloning. In vitro matured porcine oocytes derived from local slaughterhouse and fibroblasts derived from miniature pig fetuses were used for somatic cell nuclear transfer (SCNT). Reconstructed embryos were transferred to recipient pigs on the same day of SCNT or after 1~2 days of in vitro culture for selecting early cleaved embryos. Breed, parity and date of standing estrous of recipients were recorded for analysis. After 25~35 days after embryo transfer pregnancy was diagnosed using ultrasonography, and pregnant recipients were monitored till delivery. Between purebred and crossbred, no significant difference was founded in both pregnancy and delivery rates. However, early cleaved embryos showed significantly higher pregnancy (46.2%) and delivery (12.8%) rates compared to non-selectively transferred group (24.8% and 4.5%, respectively). The results also showed that the recipients showing standing estrous on the same day of SCNT and less than 4 parities were most suitable for pig cloning.

• Clinical and Experimental Reproductive Medicine
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• 제19권2호
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• pp.125-131
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• 1992

The possible effect of human follicular fluid(hFF) on the growth and development of fertilized oocytes and embryos is important because the fallopian tubes are exposed to FF after follicular rupture and the processes of fertilization and embryo cleavage occur inside the fallopian tubes. Previously, it was suggested that human FF might adversely affect on the development of early mouse embryos. In order to investigate the effect of hFF on the development of embryos, early mouse embryos were cultured in media containing various protein sources as bovine serum albumin(BSA), fetal cord serum(FCS) and FF. And we evaluated the development of early mouse embryos in terms of the morphology, cleavage rate, and cell count of blastcysts. There were no significant differences in the morula and blstocyst formation rates of 2-cell mouse embryos cultured in the media containg three different protein sources and three different concentrations of FF. The blastocyst formation rate of 1-cell mouse embryo cultured in FF group was significantly higher than that cultured in BSA group(P<0.05). The morula and blastocyst formation rates of 2-cell mouse embryos of the group cultured in the media containing FF were comparable with those of other two groups, in addition, the cell count of blastocysts of FF group in the 2-cell embryo culture was higher than those of BSA group and HCS group(P<0.01), and this finding was also noted in 1-cell embryo culture. There was no difference in the morula and blastocyst formation rates of the 2-cell mouse embryos cultured in the media containing different concentrations of FF. These results suggest that mature human follicular fluid has no inhibitory activity on the development of early mouse embryos even in high concentration and may be a good protein source which is positively associated with the development of mouse embryos in vitro especially in 1 cell embryo culture.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.153-160
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• 2014

Adaptive development of early stage embryo is well established and recently it is explored that the mammalian embryos also have adaptive ability to the stressful environment. However, the mechanisms are largely unknown. In this study, to evaluate the possible role of aquaporin in early embryo developmental adaptation, the expression of aquaporin (AQP) 5 gene which is detected during early development were examined by the environmental condition. To compare expression patterns between in vivo and in vitro, we conducted quantitative RT-PCR and analyzed localization of the AQP5 by whole mount immunofluorescence. At in vivo condition, Aqp5 expressed in oocyte and in all the stages of preimplantation embryo. It showed peak at 2-cell stage and decreased continuously until morula stage. At in vitro condition, Aqp5 expression pattern was similar with in vivo embryos. It expressed both at embryonic genome activation phase and second mid-preimplantation gene activation phase, but the fold changes were modified between in vivo embryos and in vitro embryos. During in vivo development, AQP5 was mainly localized in apical membrane of blastomeres of 4-cell and 8-cell stage embryos, and then it was localized in cytoplasm. However, the main localization area of AQP5 was dramatically shifted after 8-cell stage from cytoplasm to nucleus by in vitro development. Those results explore the modification of Aqp5 expression levels and location of its final products by in vitro culture. It suggests that expression of Aqp5 and the roles of AQP5 in homeostasis can be modulated by in vitro culture, and that early stage embryos can develop successfully by themselves adapting to their condition through modulation of the specific gene expression and localization.

• Asian-Australasian Journal of Animal Sciences
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• 제11권4호
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• pp.398-403
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• 1998

The objective of the present study was to examine the developmental rates, and the stage of development in relation to time since fertilization, of in vitro produced buffalo embryos. Buffalo cumulus-oocyte complexes obtained from slaughterhouse ovaries were matured and fertilized in vitro. The fertilized oocytes (n = 248) were then co-cultured with buffalo oviductal epithelial cells and evaluated for the developmental stages on Days 2, 4, 6, 7, 8, 9 and 10 post-insemination. The peak of 4-cell stage embryos was observed on Day 2 (63.7 %), whereas Day 4 was marked by peaks of 6-8-cell stage embryos (20.9%) and 16-cell stage embryos to early morulae (50%). On Days 6, 7, 8, 9, and 10 post-insemination, 49.5, 48.3, 38.3, 33.8 and 33.4% embryos were found to be at morula/compact morula stages, 8.8, 12.5, 25.4, 6.0 and 1.2% at early blastocyst/blastocyst stages, 0, 6.8, 7.2, 15.3 and 2.0% at expanded blastocyst stage and 0, 1.6, 4.8, 19.3 and 38.5% hatching/hatched blastocyst stages, respectively. The peaks of early blastocyst/blastocyst, expanded blastocyst and hatching/hatched blastocyst stages were observed on Days 8, 9 and 10, respectively. The percentages of oocytes which initially became arrested and subsequently degenerated were 3.6, 4.8, 10.4, 14.5, 21.3 and 24.5% on Days 4, 6, 7, 8, 9 and 10 post-insemination, respectively.

• 한국동물학회지
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• 제28권4호
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• pp.257-278
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• 1985

Phenyalanine, tryptophan, tyrosine 과 같은 방향족 아미노산을 계배 초기에 투여하였을 때 somite 형성에 미치는 영향을 광학 및 전자현미경을 사용하여 형태적으로 추구한 결과 아미노산을 투여한 계배에서는 불완전한 체절 분절 현상이 일어나고 신경계에도 감쇠 영향을 미치며 somite의 발생이 불완전하고 그 크기도 다양하였다. 또한 체절 세포는 chromatin이 응축되고 미토콘드리아의 일부는 파괴되었고 핵이 변형된 경우도 있었다. 부란 24시간 후 아미노산을 투여하고 15일간 부란한 계배의 경우 단백질이나 핵산은 대조군에 비해 크게 저하되지는 않았으나 lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase 및 glucose 6-phosphate dehydrogenase와 같은 기초대사에 중요한 구실을 하는 효소활성은 크게 저하되었다. 이와 같은 실험결과로부터 초기계배에 아미노산을 투여하면 아마도 yolk granule의 분해가 지연되며 결과적으로 세포내의 아미노산 균형이 파괴되어 정상 대사가 이루어지지 못하여 비정상적인 체절형성의 현상이 나타나게 되는 것으로 생각된다.

• Clinical and Experimental Reproductive Medicine
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• 제32권1호
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• pp.47-54
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• 2005

Objective: Evaluation of embryos using early cleavage to 2-cell stage has been proposed, but a critical time-point for selecting embryos is unclear. The aim of the present study is to provide a guideline including critical time-point in the selection of early cleaving embryo for the reduction of multiple pregnancies as well as the increase of pregnancy rate in human IVF. Methods: This prospective study was performed in 116 cycles from 85 patients who underwent conventional IVF or ICSI at the infertility clinic of Good Moonhwa Hospital from January 2002 to December 2003. Early cleavage (EC) of embryos to 2-cell stage was assessed at 25 h and 27 h postinsemination/microinjection. Embryos that had early cleaved at each time point were designated as EC-1 and EC-2, respectively, while others were designated as non-early cleavage (NEC). Results: At least one early cleavage embryo was observed in 54 (46.6%) for the EC-1 and 84 (72.4%) for the EC-2 of the 116 cycles assessed. Clinical pregnancy rates (PR) were significantly higher in the EC-1 group (66.7%) compared to the EC-2 group (53.6%) or the NEC group (31.2%) (p<0.05). Significant improvement of the pregnancy rate was found when at least two or more embryos were early cleaved at 25 h postinsemination or when the proportion of early cleavage embryo at 25 h postinsemination was higher than 20% (p<0.05). Conclusion: The critical time-point for the selection of early cleavage embryos with high implantation potential is more effective in 25 h postinsemination/microinjection compared to 27 h. The proportion as well as number of early cleavage embryos is also an important factor for the prediction of pregnancy outcome and the chance of multiple pregnancies. These results demonstrated that the evaluation of early cleavage embryos to 2-cell stage is an easy, simple, and objective method for the selection of good quality embryos suitable for embryo transfer.

• Clinical and Experimental Reproductive Medicine
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• 제41권2호
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• pp.47-61
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• 2014

Stored maternal factors in oocytes regulate oocyte differentiation into embryos during early embryonic development. Before zygotic gene activation (ZGA), these early embryos are mainly dependent on maternal factors for survival, such as macromolecules and subcellular organelles in oocytes. The genes encoding these essential maternal products are referred to as maternal effect genes (MEGs). MEGs accumulate maternal factors during oogenesis and enable ZGA, progression of early embryo development, and the initial establishment of embryonic cell lineages. Disruption of MEGs results in defective embryogenesis. Despite their important functions, only a few mammalian MEGs have been identified. In this review we summarize the roles of known MEGs in mouse fertility, with a particular emphasis on oocytes and early embryonic development. An increased knowledge of the working mechanism of MEGs could ultimately provide a means to regulate oocyte maturation and subsequent early embryonic development.

• 한국수정란이식학회지
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• 제10권2호
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• pp.171-175
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• 1995

This study was performed to establish the condition and the methods for the techniques of insertion the isolated blastomere cells into cytoplasm, in order to research the develop-mental ability of bovine embryo blastomere cells in vitro produced. After 24h in vitro ovary maturation with the ovaries from a slaughter house, in vitro fertilization was performed to the vital sperms which their mobility were decided by percoll gradient method, with 2~8 cell stage embryos, the blastomeres were isolated in $Ca^2$+. $Mg^2$+-free PBS, and following that embedded into agar and alginate solution, respectively. The rates of in vitro develop-ment are as follows ; in agar embedded 11 among 120(9.2%) 1 /2~1 /3 blastomers cleaved and 6 among 93(6.5%) 1 /4~1 /8 blastomeres cleaved. In sodium alginate-embedded 14 among 84(16.7%) 1 /2~1 /3 blastomeres cleaved and 6 among 85(7.1%) 1 /4~1 /8 blastomeres cleaved. In case of Na-alginate, the rate of the cells were better than those of agar. The results suggest that the techniques for embeeding the isolated blastomeres into gel may help cloning of bovine early embryo without nuclear transplantation.