Wnt/beta-catenin signaling controls Mespo expression to regulate segmentation during Xenopus somitogenesis

Dev Biol. 2007 Apr 15;304(2):836-47. doi: 10.1016/j.ydbio.2006.12.034. Epub 2006 Dec 21.


The vertebral column is derived from somites, which are transient segments of the paraxial mesoderm that are present in developing vertebrates. The strict spatial and temporal regulation of somitogenesis is of crucial developmental importance. Signals such as Wnt and FGF play roles in somitogenesis, but details regarding how Wnt signaling functions in this process remain unclear. In this study, we report that Wnt/beta-catenin signaling regulates the expression of Mespo, a basic-helix-loop-helix (bHLH) gene critical for segmental patterning in Xenopus somitogenesis. Transgenic analysis of the Mespo promoter identifies Mespo as a direct downstream target of Wnt/beta-catenin signaling pathway. We also demonstrate that activity of Wnt/beta-catenin signaling in somitogenesis can be enhanced by the PI3-K/AKT pathway. Our results illustrate that Wnt/beta-catenin signaling in conjunction with PI3-K/AKT pathway plays a key role in controlling development of the paraxial mesoderm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / biosynthesis*
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Gene Expression Regulation, Developmental
  • Phosphatidylinositol 3-Kinases / physiology
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-akt / physiology
  • Signal Transduction
  • Somites / physiology*
  • Wnt Proteins / metabolism
  • Wnt Proteins / physiology*
  • Xenopus / embryology
  • Xenopus / physiology*
  • Xenopus Proteins / biosynthesis*
  • Xenopus Proteins / genetics
  • beta Catenin / metabolism
  • beta Catenin / physiology*


  • Basic Helix-Loop-Helix Transcription Factors
  • Msgn1 protein, Xenopus
  • Wnt Proteins
  • Xenopus Proteins
  • beta Catenin
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt