Cdx2 is required for correct cell fate specification and differentiation of trophectoderm in the mouse blastocyst

• DOI: 10.1242/dev.01801
• Publication Date: 2005-03-24T02:29:09Z
• Authors: Dan Strumpf; Chai-An Mao; Yojiro Yamanaka; Amy Ralston; Kallayanee Chawen...; Felix Beck; Janet Rossant
• Keywords: Inner cell mass; Homeobox protein NANOG; Trophoblast; Blastocoel; Nanog Homeobox Protein; CDX2

Blastocyst formation marks the segregation of first two cell lineages in mammalian preimplantation embryo: inner mass (ICM) that will form embryo proper and trophectoderm (TE) gives rise to trophoblast lineage. Commitment ICM lineage is attributed function transcription factors, Oct4 (encoded by Pou5f1) Nanog. However, a positive regulator TE fate has not been described. The T-box protein eomesodermin (Eomes) caudal-type homeodomain Cdx2 are expressed TE, both Eomes Cdx2homozygous mutant embryos die around time implantation. A block early differentiation occurs blastocysts. blastocysts implant, Oct4expression correctly restricted TE. Blastocoel initiates mutants but epithelial integrity maintained fail implant. Loss results failure downregulate Nanog outer cells blastocyst subsequent death those cells. Thus, essential for at stage ensuring repression