The Notch signaling pathway in the cnidarian Hydra

Dev Biol. 2007 Mar 1;303(1):376-90. doi: 10.1016/j.ydbio.2006.11.022. Epub 2006 Nov 17.

Abstract

Many of the major pathways that govern early development in higher animals have been identified in cnidarians, including the Wnt, TGFbeta and tyrosine kinase signaling pathways. We show here that Notch signaling is also conserved in these early metazoans. We describe the Hydra Notch receptor (HvNotch) and provide evidence for the conservation of the Notch signaling mode via regulated intramembrane proteolysis. We observed that nuclear translocation of the Notch intracellular domain (NID) was inhibited by the synthetic gamma-secretase inhibitor DAPT. Moreover, DAPT treatment of hydra polyps caused distinct differentiation defects in their interstitial stem cell lineage. Nerve cell differentiation proceeded normally but post-mitotic nematocyte differentiation was dramatically reduced. Early female germ cell differentiation was inhibited before exit from mitosis. From these results we conclude that gamma-secretase activity and presumably Notch signaling are required to control differentiation events in the interstitial cell lineage of Hydra.

Publication types

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

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Active Transport, Cell Nucleus / physiology*
  • Amino Acid Sequence
  • Animals
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology*
  • Gene Components
  • Germ Cells / drug effects
  • Green Fluorescent Proteins
  • Hydra / physiology*
  • In Situ Hybridization
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Neurons / drug effects
  • Receptors, Notch / genetics
  • Receptors, Notch / metabolism*
  • Signal Transduction / physiology*
  • Triglycerides / toxicity
  • gamma-Aminobutyric Acid / analogs & derivatives
  • gamma-Aminobutyric Acid / toxicity

Substances

  • Receptors, Notch
  • Triglycerides
  • Green Fluorescent Proteins
  • gamma-Aminobutyric Acid
  • 1,2-dilinolenoyl-3-(4-aminobutyryl)propane-1,2,3-triol