Zoomorphology

, Volume 106, Issue 2, pp 115–122 | Cite as

The ventral epithelium of Trichoplax adhaerens (Placozoa): Cytoskeletal structures, cell contacts and endocytosis

  • August Ruthmann
  • Gabriele Behrendt
  • Regina Wahl
Article
Received:

Summary

All cilia emerge from ciliary pits supported along their circumference by 22–24 dense rodlets that are connected by filaments to a surrounding sheath of endoplasmic reticulum. The proximal part of the basal body is provided with two short lateral rootlets and one long terminal rootlet, all associated with microtubules. The lateral rootlets are in turn connected by fine fibrous material to the dense supporting rodlets which follow the contour of the ciliary pit and extend along the ciliary membrane beyond the level of the basal plate where the central pair of microtubules originates. The proximal part of the basal body has fine fibrous connections to the endoplasmic reticulum while its distal portion is surrounded by nine curved sheets. The terminal cell contactions are by belt desmosomes that are accompanied by a bundle of microfilaments which encircle the apical region of the cell and insert at the cell membrane. Tight junctions are lacking. Endocytosis was demonstrated by the uptake of cationized ferritin. The structures associated with the ciliary pits are probably associated with the firm anchorage of the ciliary base since Trichoplax adheres to the substrate as it moves propelled by its ventral cilia. The marginal bundle of microfilaments may be involved in folding of the organism during feeding.

Keywords

Ferritin Proximal Part Basal Body Terminal Cell Central Pair 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alberts B, Bray D, Lewis J, Raff M, Roberts K, Watson D (1984) Molecular biology of the cell. Garland, New York LondonGoogle Scholar
  2. Anderson RGW (1972) The three-dimensional structure of the basal body from the rhesus monkey oviduct. J Cell Biol 54:246–265Google Scholar
  3. Condeelis J (1979) Isolation of concanavalin A caps during various stages of formation and their association with actin and myosin. J Cell Biol 80:751–758Google Scholar
  4. Doolin PF, Birge WJ (1966) Ultrastructural organization of cilia and basal bodies of the epithelium of the choroid plexus in the chick embryo. J Cell Biol 29:333–345Google Scholar
  5. Flock Å, Duvall AJ (1965) The ultrastructure of the kinocilium of the sensory cells in the inner ear and lateral line organs. J Cell Biol 25:1–8Google Scholar
  6. Gibbons IR (1961) The relationship between the fine structure and direction of beat in gill cilia of a lamillibranch mollusc. J Cell Biol 11:179–205Google Scholar
  7. Gibbons IR, Grimstone AV (1960) On flagellar structure in certain flagellates. J Biophys Biochem Cytol 7:697–716Google Scholar
  8. Gilula NB, Satir P (1972) The ciliary necklace. A ciliary membrane specialization. J Cell Biol 53:494–509Google Scholar
  9. Grell KG (1971) Trichoplax adhaerens F.E. Schulze und die Entstehung der Metazoen. Naturwiss Rundschau 24:160–162Google Scholar
  10. Grell KG, Benwitz G (1971) Die Ultrastruktur von Trichoplax adhaerens F.E. Schulze. Cytobiol 4:216–240Google Scholar
  11. Grell KG, Benwitz G (1974) Spezifische Verbindungsstrukturen der Faserzellen von Trichoplax adhaerens F.E. Schulze. Z Naturforsch 29c:790Google Scholar
  12. Grell KG, Benwitz G (1981) Ergänzende Untersuchungen zur Ultrastruktur von Trichoplax adhaerens F.E. Schulze (Placozoa). Zoomorphology 98:47–67Google Scholar
  13. Hull BE, Staehelin LA (1979) The terminal web. A reevaluation of its structure and function. J Cell Biol 81:67–82Google Scholar
  14. Karfunkel P (1974) The mechanisms of neural tube formation. Int Rev Cytol 38:245–271Google Scholar
  15. Mooseker MS, Tilney LG (1975) Organization of an actin filamentmembrane complex. Filament polarity and membrane attachment in the microvilli of intestinal epithelial cells. J Cell Biol 67:725–743Google Scholar
  16. Pitelka DR (1974) Basal bodies and root structures. In: Sleigh MA (ed) Cilia and flagella. Academic Press, London New York, p 417Google Scholar
  17. Reese TS (1965) Olfactory cilia in the frog. J Cell Biol 25:209–230Google Scholar
  18. Ruthmann A (1977) Cell differentiation, DNA content and chromosomes of Trichoplax adhaerens F.E. Schulze. Cytobiology 15:58–64Google Scholar
  19. Schroeder T (1973) Actin in dividing cells: contractile ring filaments bind heavy meromyosin. Proc Nat Acad Sci 70:1688–1692Google Scholar
  20. Sleigh M (1979) Contractility of the roots of flagella and cilia. Nature 277:263–264Google Scholar
  21. Weiss RL, Goodenough DA, Goodenough UW (1977) Membrane particle arrays associated with the basal body and with contractile vacuole secretion in Chlamydomonas. J Cell Biol 72:133–143Google Scholar
  22. Welsch U, Storch V (1969) Zur Feinstruktur und Histochemie des Kiemendarms und der „Leber“ von Branchiostoma lanceolatum (Pallas). Z Zellforsch 102:432–446Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • August Ruthmann
    • 1
  • Gabriele Behrendt
    • 1
  • Regina Wahl
    • 1
  1. 1.Ruhr-Universität Bochum, Lehrstuhl für ZellmorphologieBochum 1Federal Republic of Germany

Personalised recommendations