The mouse preimplantation embryo generates the precursors of trophectoderm (TE) and inner cell mass (ICM) during the 8- to 16-cell stage transition, when the apico-basal polarized blastomeres undergo divisions that give rise to cells with different fate. Asymmetric segregation of polar domain at 8-16 cell division generate two cell types, polar cells which adopt an outer position and develop in...

Polarity formation in preimplantation embryos is controversial. To investigate the embryonic-abembryonic axis in the pig, porcine parthenotes were used to prevent the topological change caused by polyspermy as well as to avoid the influences of sperm entry position. For lineage tracing, DiI, a fluorescence dye, was injected into only a blastomere of the 2-cell stage embryos. If the first blasto...

OBJECTIVE We studied the effect of the site of laser zona opening on the complete hatching of mouse blastocysts and the cell numbers of the completely hatched blastocysts. METHODS Mouse blastocysts were randomly allocated to the inner cell mass (ICM) group (zona opening performed at the site of the ICM, n=125), the trophectoderm (TE) group (zona opening performed opposite to the ICM, n=125) a...

immediate early step in PrE specification. We show that the fraction cells present with in this state is influenced by factors that both promote and suppress primitive PrE differentiation, however conditions that support ES cell self-renewal prevent their progression into endoderm differentiation and support an equilibrium between this state and at least one other that resembles the inner cell ...

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from...

The first cell differentiation in mammalian embryos segregates polarized trophectoderm cells from an apolar inner cell mass (ICM). This lineage decision is specified in compacted morulae by cell polarization and adhesion acting on the Yes-associated protein in the Hippo signaling pathway, but the regulatory mechanisms are unclear. We show that morula compaction and ICM formation depend on PC7 a...

received: 23/sep/2008, accepted: 23/nov/2008oct-4/ pou5f1/ oct-3, a pou domain family protein acts as a crucial transcription factor dur- ing embryonic development. it helps in maintenance of self renewal as well as pluripotential state of embryonic stem (es) cells. its expression starts right from 2 cell stage especially prior to 8 cell stage till the blastocyst stage where it is strongly exp...