Oct4 protein remains in trophectoderm until late stages of mouse blastocyst development

Reprod Biol. 2011 Jul;11(2):145-56. doi: 10.1016/s1642-431x(12)60051-5.


Oct-4, the marker of pluripotent cells, is crucial for murine preimplantation development. During the formation of the blastocyst Oct-4 is downregulated in the trophectoderm (TE) and its expression becomes restricted to the inner cell mass (ICM). In order to determine the exact timing of the disappearance of Oct-4 protein from TE we analyzed the localization and level of Oct-4 at different stages of blastocyst development. The presence of Oct-4 protein was determined by immunohistochemistry using confocal microscopy. We found that the downregulation of Oct-4 protein in TE of mouse blastocysts progresses gradually during development, and Oct-4 protein persists in some of the TE cells at least until the expanded blastocyst (120-140 cells) stage. Our findings indicate that the switching-off of the Oct-4 expression is not necessary for the trophectoderm formation. The complete elimination of Oct-4 protein from TE occurs at the period of blastocyst implantation, when lack of Oct-4 is required for the proper functioning of the trophectoderm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blastocyst / physiology*
  • Down-Regulation
  • Ectoderm / metabolism*
  • Female
  • Gene Expression Regulation, Developmental / physiology*
  • Mice
  • Octamer Transcription Factor-3 / genetics
  • Octamer Transcription Factor-3 / metabolism*


  • Octamer Transcription Factor-3
  • Pou5f1 protein, mouse