ZFIN ID: ZDB-PUB-010509-1
Mesendoderm: An Ancient Germ Layer?
Rodaway, A. and Patient, R.
Date: 2001
Source: Cell   105(2): 169-172 (Review)
Registered Authors: Patient, Roger K., Rodaway, Adam
Keywords: none
MeSH Terms:
  • Animals
  • Caenorhabditis elegans/embryology
  • DNA-Binding Proteins/metabolism*
  • Germ Layers/cytology
  • Germ Layers/physiology*
  • Morphogenesis/physiology*
  • Signal Transduction/physiology
  • Transcription Factors/metabolism*
  • Transforming Growth Factor beta/metabolism
  • Zebrafish/embryology
PubMed: 11336666 Full text @ Cell
Formation of the three primary germ layers, ectoderm, mesoderm, and endoderm, is an early distinction between groups of cells in developing embryos. Our understanding of their generation in vertebrates has benefitted from the classical experiments of Nieuwkoop and his colleagues (referenced in Nieuwkoop, 1997), in which explants of tissue from the animal hemisphere of amphibian embryos (fated to form ectoderm) apposed to explants of vegetal tissue (fated to form endoderm) were induced to form mesoderm. These results have been widely interpreted as indicating that mesoderm forms at the interface between presumptive endoderm and presumptive ectoderm as a consequence of inductive signals from the former to the latter. However, recent data from nematodes and zebrafish suggest that endoderm and some portion of the mesoderm may derive from a bipotential layer of cells, called the mesendoderm. In addition, the genes involved in this process may be conserved.