Conditional specification of endomesoderm

Cells Dev. 2021 Sep:167:203716. doi: 10.1016/j.cdev.2021.203716. Epub 2021 Jul 7.


Early in animal development many cells are conditionally specified based on observations that those cells can be directed toward alternate fates. The endomesoderm is so named because early specification produces cells that often have been observed to simultaneously express both early endoderm and mesoderm transcription factors. Experiments with these cells demonstrate that their progeny can directed entirely toward endoderm or mesoderm, whereas normally they establish both germ layers. This review examines the mechanisms that initiate the conditional endomesoderm state, its metastability, and the mechanisms that resolve that state into definitive endoderm and mesoderm.

Keywords: Conditional specification; Endoderm; Frog; Hemichordate; Mesoderm; Nematode; Regulative development; Sea urchin; Tunicate; Zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Body Patterning*
  • Endoderm / embryology*
  • Humans
  • Mesoderm / embryology*
  • Models, Biological
  • Sea Urchins / embryology
  • Signal Transduction