Modulation of embryonic intracellular Ca2+ signaling by Wnt-5A

Dev Biol. 1997 Feb 1;182(1):114-20. doi: 10.1006/dbio.1996.8463.


Wnt genes encode secreted proteins which are implicated in receptor-mediated cell-cell signaling events important in embryogenesis, but the second messenger systems modulated by Wnts have not been identified. We report that ectopic expression of Xwnt-5A in zebrafish embryos enhances the frequency of intracellular Ca2+ transients in the enveloping layer of the blastodisc, whereas Xwnt-8 does not. These transients are independent of extracellular Ca2+. Consistent with the observed Ca2+ transients playing a role in responses of embryos to Xwnt-5A, we report that the ligand-activated serotonin type 1C receptor, which stimulates PI cycle activity and Ca2+ signaling independent of Wnts, phenocopies embryonic responses to Xwnt-5A. These results suggest that intercellular signaling by a subset of vertebrate Wnts involves modulation of a intracellular Ca2+ signaling pathway, which may arise from phosphatidylinositol cycle activity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blastocyst / physiology*
  • Calcium / metabolism*
  • Embryo, Nonmammalian / physiology
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins / physiology*
  • Receptor, Serotonin, 5-HT2C
  • Receptors, Serotonin / biosynthesis
  • Receptors, Serotonin / physiology*
  • Signal Transduction*
  • Vertebrates
  • Wnt Proteins
  • Wnt-5a Protein
  • Zebrafish


  • Proto-Oncogene Proteins
  • Receptor, Serotonin, 5-HT2C
  • Receptors, Serotonin
  • WNT5A protein, human
  • Wnt Proteins
  • Wnt-5a Protein
  • Calcium