| dc.description.abstract | Understanding of events leading to inner cell mass (ICM) and trophectoderm (TE) specification would be of enthusiasm to help understand some of the issues observed in embryos produced in vitro. During preimplantation development, CDX2 is known to be involved in the development of the TE, one of first differentiation event of the embryo. However in the mouse, the timing of CDX2 expression during the early development still remain unclear. The goal of this research is to study when exactly CDX2 was expressed during the early development, special in the expanded blastocyst stage. In this study, in vitro fertilized ICR mouse embryo are used to study for (1) characteristic of preimplantation development of in vitro fertilized embryos and (2) the timing of the CDX2 expression. In the first experiment, I found that high percentage of the in vitro fertilized ICR mice were developed to the 2-cell, 4-cell, and 8-cellstage embryo. However only 23.4% of fertilized embryos can develop to the expanded blastocyst stage. Following that the first differentiation of embryos during preimplantation development into TE and ICM using CDX2 a TE cells marker and OCT4, an ICM cell marker were examined. This experiment shows that the time for the first expression of CDX2 will be occurred at the late eight-cells tage embryo in the haft of embryonic cells. At the morula stage, the number of embryonic cells positive with CDX2 were increased, however OCT4 was detected in all of embryonic cells. At the expanded blastocyst stage, CDX2 were detected only in TE cells and disappeared in ICM cells. Furthermore, this research is aimed at generating a more complete understanding of early embryonic development, as well as generating tools needed to manipulate cells of the early embryo.
Keywords: CDX2, Pre-implantation development, In vitro fertilization, Immunocytochemistry | en_US |
