The fine structure of differentiating interstitial cells in Hydra

  • Thomas L. Lentz


Interstitial cells of hydra are small undifferentiated cells containing an abundance of free ribosomes and few other cytoplasmic organelles. They are capable of differentiating into epitheliomuscular, digestive, glandular, nerve cells, and cnidoblasts. Developing epitheliomuscular and digestive cells acquire bundles of filaments, 50 Å in diameter, which later are incorporated into the muscular processes. Early gland cells develop an elaborate rough-surfaced endoplasmic reticulum and one or more Golgi apparatus. Secretory granules originate in the Golgi region eventually filling the apex of the cell. Neurons are recognized first by the presence of an elaborate Golgi apparatus, absence of a well-developed endoplasmic reticulum, and later the appearance of cytoplasmic processes. The most striking feature of nematocyst formation by cnidoblasts is the presence of a complex distribution system between protein synthesizing rough-surfaced endoplasmic reticulum and the nematocyst. This system consists of connections between cisternae of the endoplasmic reticulum with smooth Golgi vesicles which in turn are connected to minute tubules, 200 Å in diameter. The tubules extend from the Golgi region around the nematocyst finally entering the limiting membrane of the nematocyst. It is suggested that the interstitial cells of hydra represent a model system for the investigation of many aspects of cell differentiation.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Brien, P.: La pérennité somatique. Biol. Rev. 28, 308–349 (1953).Google Scholar
  2. Burnett, A.L.: The maintenance of form in hydra. In: D. Rudnick, ed., Regeneration, p. 27–52. New York: Ronald Press 1962.Google Scholar
  3. Chapman, G.B.: The fine structure of the stenoteles of hydra. In: H.M. Lenhoff and W.F. Loomis, eds., The Biology of Hydra and of some other Coelenterates, p. 131–152. Coral Gables, Florida: Univ. of Miami Press 1961.Google Scholar
  4. —, and L.G. Tilney: Cytological studies of the nematocysts of hydra. I. Desmonemes, isorhizas, cnidocils and supporting structures. J. biophys. biochem. Cytol. 5, 69–78 (1959a).Google Scholar
  5. —: II. The stenoteles. J. biophys. biochem. Cytol. 5, 79–84 (1959b).Google Scholar
  6. Farquhar, M.G., and J.F. Rinehart: Electron microscopic studies of the anterior pituitary gland of castrate rats. Endocrinology 54, 516–541 (1954).Google Scholar
  7. Feldman, D.G.: A method of staining thin sections with lead hydroxide for precipitate-free sections. J. Cell Biol. 15, 592–595 (1962).Google Scholar
  8. Freeman, J.A., and B.O. Spurlock: A new epoxy embedment for electron microscopy. J. Cell Biol. 13, 437–443 (1962).Google Scholar
  9. Hess, A.: The fine structure of cells in Hydra. In: H.M. Lenhoff and W.F. Loomis, eds., The Biology of Hydra and of some other Coelenterates, p. 1–50. Coral Gables, Florida: Univ. of Miami Press 1961.Google Scholar
  10. —, A.I. Cohen, and E.A. Robson: Observations on the structure of hydra as seen with the electron and light microscopes. Quart. J. micr. Sci. 98, 315–326 (1957).Google Scholar
  11. Lentz, T.L., and R.J.Barrnett: Fine structure of the nervous system of Hydra. Amer. Zoologist, in press (1965a).Google Scholar
  12. - Surface specializations of hydra cells: The effect of enzyme inhibitors on ferritin uptake. J. Ultrastruct. Res., in press (1965b).Google Scholar
  13. Loomis, W.F., and H.M. Lenhoff: Growth and sexual differentiation of hydra in mass culture. J. exp. Zool. 132, 555–568 (1956).Google Scholar
  14. Palade, G. E., P. Siekevitz, and L.G. Caro: Structure, chemistry, and function of the pancreatic exocrine cell. In: A.V.S. de Reuck and M.P.Cameron, eds., Ciba Foundation Symposium on The Exocrine Pancreas, p. 23–55. Boston: Little, Brown & Co. 1962.Google Scholar
  15. Sabatini, D.D., K. Bensch, and R.J. Barrnett: The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J. Cell Biol. 17, 19–58 (1963).Google Scholar
  16. Slautterback, D.B.: Nematocyst development. In: H.M. Lenhoff and W.F. Loomis, eds., The Biology of Hydra and of some other Coelenterates, p. 77–129. Coral Gables, Florida: Univ. of Miami Press 1961.Google Scholar
  17. —: Cytoplasmic microtubules. I. Hydra. J. Cell Biol. 18, 367–388 (1963).Google Scholar
  18. —, and D.W. Fawcett: The development of the cnidoblasts of hydra. An electron microscope study of cell differentiation. J. biophys. biochem. Cytol. 5, 441–452 (1959).Google Scholar
  19. Tardent, P.: Regeneration in the hydrozoa. Biol. Rev. 38, 293–333 (1963).Google Scholar
  20. Wood, R.L.: Intercellular attachment in the epithelium of Hydra as revealed by electron microscopy. J. biophys. biochem. Cytol. 6, 343–352 (1959).Google Scholar

Copyright information

© Springer-Verlag 1965

Authors and Affiliations

  • Thomas L. Lentz
    • 1
  1. 1.Department of AnatomyYale University School of MedicineNew HavenUSA

Personalised recommendations