Signaling pathways and axis formation in the lower metazoa

Curr Top Dev Biol. 2011;97:137-77. doi: 10.1016/B978-0-12-385975-4.00012-7.


The determination of the body axis in the last common ancestor of bilaterian animals is still a matter of debate. While Hox genes pattern the formation of the primary, anteroposterior body axis in bilaterians, there is growing evidence from lower metazoans that the Wnt/β-catenin pathway acts as the primordial signaling system in this process. This review summarizes molecular data from recent genomic analyses of basal model organisms with a focus on the evolution of signaling pathways involved in the establishment of the primary and successive body axes during early metazoan evolution.

Publication types

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

MeSH terms

  • Animals
  • Biological Evolution
  • Body Patterning / genetics*
  • Bone Morphogenetic Proteins* / genetics
  • Bone Morphogenetic Proteins* / metabolism
  • Gene Expression Regulation, Developmental
  • Genes, Homeobox / genetics*
  • Invertebrates / classification
  • Invertebrates / genetics*
  • Molecular Sequence Data
  • Nodal Protein / genetics
  • Nodal Protein / metabolism
  • Phylogeny
  • Receptors, Transforming Growth Factor beta / genetics
  • Receptors, Transforming Growth Factor beta / metabolism
  • Smad Proteins* / genetics
  • Smad Proteins* / metabolism
  • Wnt Proteins* / genetics
  • Wnt Proteins* / metabolism
  • Wnt Signaling Pathway / genetics*
  • beta Catenin* / genetics
  • beta Catenin* / metabolism


  • Bone Morphogenetic Proteins
  • Nodal Protein
  • Receptors, Transforming Growth Factor beta
  • Smad Proteins
  • Wnt Proteins
  • beta Catenin