Published in Scientific Works. Series C. Veterinary Medicine, Vol. LXI
Written by Duygu MUTLUAY
Preimplantation is a process in which embryo is prepared for implantation to the wall of the uterus. This stage defines some morphological changes that occur in the first three days after fertilization during mouse development. It culminates in the generation of the blastocysts, which has a fluid-filled inner cavity and two distinct cell lineages. These two distinct cell lineages consist of trophectoderm (TE) and inner cell mass (ICM). While TE cells contribute to the placenta and the extraembryonic membranes and allow the blastocysts to implant in the mother’s uterine wall, the pluripotent inner cell mass gives rise to the fetus. Some transcription factors such as Cdx2 and Oct4 (Pou5f1) have been identified in the mouse blastocyst to generate TE and ICM. Cdx2 is specifically expressed in TE and suppresses the expression of Oct4. Oct4, a key regulator of pluripotency, is strongly expressed in ICM and is essential for early lineage segregation. To present the localization of this transcription factors, we flushed 2 cell stage embryos from the oviducts and cultured to late blastocyst stage in medium. Samples were fixed and immunostained with mouse anti-Cdx2, goat anti-Pou5f1, then images were assessed using a fluorescence microscope to show the localization and presence of Cdx2 and Oct4 by immunocytochemistry. In this work, we demonstrated and reviewed the current knowledge on the Cdx2 and Oct4 in the formation of TE and ICM that is important for understanding the mechanisms of mouse embryo development.
[Read full article] [Citation]
