• 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.

• 한국수정란이식학회지
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• 제24권1호
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• pp.65-69
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• 2009

The aim of the present study was to investigate the cleavage pattern, its developmental ability and apoptosis of porcine embryo in vitro. Morphology data on a total of 919 embryos were analyzed retrospectively. Forty-eight hours after insemination, embryos were classified into five groups based on the cleavage state as follows; 1 cell, 2 cell, 4 cell, 5 to 8 cell and fragmentation. These groups were cultured another 120 hours and then evaluated for blastocyst formation. Blastocyst formation rates were significantly higher in 4 cell (42.5%) and 5 to 8 cell (48.6%) cleaving groups than in other groups (p<0.05). On the other hand, 2 cell and fragmentation groups produced 4.9% and 3,9% blastocysts, respectively. And we could verify that in the event of 2 cell block and fragmentation of embryo. To analyze the apoptotic frequency in preimplantation development of porcine IVF embryos, all cells of each blastocyst were performed by TUNEL assay. There were no significantly differences in the total cell numbers of embryos and apoptotic cell rate in blastocysts among the each classified groups. Data suggest that 4 cell and 5 to 8 cell cleaving embryos at 48 hour after insemination have high developmental competence, and may be an useful parameter to predict the development of preimplantation embryos and to study using preimplanation embryonic research.

• Reproductive and Developmental Biology
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• 제31권3호
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• pp.193-198
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• 2007

본 연구는 소의 초기 난할 단계인 2 또는 4세포기 수정란의 특정 분할구가 배반포 단계의 내부 세포괴(Inner Cell Mass)와 영양막 세포(Trophectoderm cells)로의 발달 운명이 미리 정해지는 지를 확인하기 위해 실시되었다. 먼저 생쥐의 체내수정란과 소의 체외 수정란에서 배반포의 영양막 세포에서만 특이적으로 발현하는 cdx2단백질의 발현 양상을 조사하였다. 또한, 소의 경우 2세포기와 4세포기가 내부 세포괴와 영양막 세포로 나눠지는 시점인지를 조사하기 위해 2 또는 4세포기의 특정 분할구에 Dextran의 주입 실험과 분할구 제거 실험을 통해 ICM과 TE 형성을 확인하였다. cdx2의 발현 경향은 생쥐와 소의 2세포기일 때 대칭과 비대칭적으로 발현되는 것을 확인하였다. 생쥐의 4, 8세포기 및 상실배기에서는 분할구 전체에서 발현되었으나, 소 수정란의 분할구에서는 전체 또는 부분적으로 발현되었다. 또한, 생쥐와 소의 배반포기에서는 영양막 세포에서만 발현이 되는 것을 확인하였다. 소 수정란의 2세포기와 4세포기 단계에서 특정 분할구에 주입된 De xtran은 배반포의 내부 세포괴와 영양막 세포의 양쪽에 분포된 것을 관찰할 수 있었다. 2세포기 단계에서 하나의 분할구가 제거된 수정란 역시 ICM 및 TE 세포를 지닌 정상 배반포로 발달함을 확인하였다. 따라서 본 연구 결과는 영양막 세포에서만 특이적으로 발현하는 cdx2의 발현이 2 또는 4세포기 단계 소 수정란에서는 특별한 차이를 보이지 않으며, 궁극적으로 난할 초기에는 ICM과 TE 세포로의 운명이 결정되지 않는다는 것을 보여준다.

• 한국수정란이식학회지
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• 제30권4호
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• pp.319-325
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• 2015

Gangliosides exist in glycosphingolipid-enriched domains on the cell membrane and regulate various functions such as adhesion, differentiation, and receptor signaling. Ganglioside GM3 by ST3GAL5 enzyme provides an essential function in the biosynthesis of more complex ganglio-series gangliosides. However, the role of gangliosides GM3 in porcine oocytes during in vitro maturation and early embryo development stage has not yet understood clear. Therefore, we examined ganglioside GM3 expression patterns under apoptosis stress during maturation and preimplantation development of porcine oocytes and embryos. First, porcine oocytes cultured in the NCSU-23 medium for 44 h after $H_2O_2$ treated groups (0.01, 0.1, 1 mM). After completion of meiotic maturation, the proportion MII (44 h) was significantly different among control and the H2O2 treated groups ($76.8{\pm}0.3$ vs $69.1{\pm}0.4$; 0.01 mM, $55.7{\pm}1.0$; 0.1 mM, $38.2{\pm}1.6%$; 1 mM, P<0.05). The expressions of ST3GAL5 in $H_2O_2$ treated groups were gradually decreased compared with control group. Next, changes of ST3GAL5 expression patterns were detected by using immunofluorescene (IF) staining during preimplantation development until blastocyst. As a result, we confirmed that the expressions of ST3GAL5 in cleaving embryos were gradually decreased (P<0.05) according to the early embryo development progress. Based on these results, we suggest that the ganglioside GM3 was used to the marker as pro-apoptotic factor in porcine oocyte of maturation and early embryo production in vitro, respectively. Furthermore, our findings will be helpful for better understanding the basic mechanism of gangliosides GM3 regulating in oocyte maturation and early embryonic development of porcine in vitro.