돼지 체외 수정란의 밀착화작용 정도에 따른 beta-catenin 발현 양상과 배반포로의 발생빈도에 관한 연구
Differential compaction patterns of porcine embryos affecting on developmental ability and beta-catenin gene expression in vitro
돼지난포란 돼지수정란 밀착화작용;
- 원문 URL
Embryonic compaction is an important process as first critical event during embryonic development in mammalian preimplantation embryos. Especially, beta-catenin is a multi-functional protein involved in cell adhesion, cell signaling, and developmental fate specification. In this study, we examined the relationship between compaction pattern and expression of beta-catenin according to developmental speed. Then, we also investigated the characteristics of compaction pattern, developmental divergence and beta-catenin gene expression from mono- and poly-spermic embryos. Porcine cumulus-oocyte complexes were matured in North Carolina State University (NCSU) 23 medium for 44 h. After the completion of in vitro maturation (IVM), oocytes were coincubated with sperm concentration of 1.5×10^(5)/ml) for 6 h. After IVF, oocytes were cultured in NCSU 23 medium supplementedwith 0.4% BSA. Firstly, we confirmed that considerable differences in the blastocysts formation and their qualities were detected by whether porcine embryos would be occurred compaction or not. Therefore, we investigated the correlation with embryonic compaction and the expression of beta-catenin. As the results of beta-catenin expression in preimplantation stage porcine embryos, the signal of beta-catenin was appeared in the boundary of membrane surface between blastomeres in 2-cell and 4-cell stage, and was appeared irregular patterns from 8-cell to blastocyst stage embryos. To investigate the blastocyst formation and the expression of beta-catenin in vitro-produced porcine embryos, morula stage embryos were individually classified into three presumptive groups (full-, partial- and non-compaction) according to the degree of embryonic compaction and developmental speed. The potential for development of fully compacted embryos to blastocysts was higher than those of partial- and non-compacted embryos. And also, the expression intensity of beta-catenin in fully compacted embryos was stronger than those of partial- and non-compacted embryos. Especially, the beta-catenin gene in blastocyst stage embryos derived from fully compacted morula (4-cell stage at Day 2.5) at Day 4 after IVF was regularly expressed, but the embryos derived from partial- and non-compacted morula were showed irregular expression patterns of beta-catenin gene. These results suggest that early embryonic developmental speed and compaction patterns may be due to aberrant distribution of beta-catenin signal. Then, the developmental ability and expression of beta-catenin were showed similar pattern in polyspermic embryos. However, blastocyst formation from poly-spermic embryos was lower than that of normal embryos, and the polyspermic embryos had little total cell number in blastocyst stage. They were also weakly expressed compare with mono-spermic embryos according to degree of general compaction. Our findings suggest that aberrant expression of beta-catenin was occurred in morula stage, which associated with embryo quality and further development in porcine embryos in vitro. Although full compaction was induced from poly-spermic embryos, these embryos had lower developmental competence and weak expression of beta-catenin gene than that of mono-spermic embryos.