Totipotent migratory stem cells in a hydroid

Dev Biol. 2004 Nov 1;275(1):215-24. doi: 10.1016/j.ydbio.2004.08.006.


Hydroids, members of the most ancient eumetazoan phylum, the Cnidaria, harbor multipotent, migratory stem cells lodged in interstitial spaces of epithelial cells and are therefore referred to as interstitial cells or i-cells. According to traditional understanding, based on studies in Hydra, these i-cells give rise to several cell types such as stinging cells, nerve cells, and germ cells, but not to ectodermal and endodermal epithelial cells; these are considered to constitute separate cell lineages. We show here that, in Hydractinia, the developmental potential of these migratory stem cells is wider than previously anticipated. We eliminated the i-cells from subcloned wild-type animals and subsequently introduced i-cells from mutant clones and vice versa. The mutant donors and the wild-type recipients differed in their sex, growth pattern, and morphology. With time, the recipient underwent a complete conversion into the phenotype and genotype of the donor. Thus, under these experimental conditions the interstitial stem cells of Hydractinia exhibit totipotency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Apoptosis / drug effects
  • Bromodeoxyuridine
  • Cell Differentiation / physiology
  • Cell Division / physiology
  • Cell Movement / physiology*
  • Chimera / physiology
  • Cnidaria / physiology*
  • Mitomycin / pharmacology
  • Staining and Labeling
  • Totipotent Stem Cells / cytology
  • Totipotent Stem Cells / drug effects
  • Totipotent Stem Cells / physiology*


  • Antibiotics, Antineoplastic
  • Mitomycin
  • Bromodeoxyuridine