Summary
The actinopods Ciliophrys marina and Heterophrys marina both have membrane bounded extrusomes attached to their cellular and axopodial membranes. The extrusomes of C. marina, the muciferous bodies, are fairly simple in structure and contain a homogeneous osmiophilic substance. Their attachment site is characterized by a rectangular array of freeze fracture particles in the cell membrane. The extrusomes of H. marina, the conicysts, are more complex and contain a two-part osmiophilic body. The attachment site of conicysts is characterized by a rosette of 8 freeze fracture particles very similar to the 9-particle rosette found at the mucocyst attachment sites in Tetrahymena. Furthermore, intracytoplasmic bridges connect the conicyst and cell membrane faces, and a specialized fibrillar structure is found on the cell membrane in the region of conicyst attachment. The various possible roles for such particle arrays are discussed and their presence in virtually all extrusomes is predicted.
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Allen, R.D., Hausmann, K.: Membrane behavior of exocytic vesicles 1. The ultrastructure of Paramecium trichocysts in freeze fracture. J. Ultrastruct. Res. 54, 224-234
Bardele, C.F.: Ultrastruktur der „Körnchen” auf den Axopodien von Raphidiophrys (Centrohelida, Heliozoa). Z. Naturforsch. 24b, 362–363 (1969)
Bardele, R.F.: Comparative ultrastructure of Centrohelida. J. Protozool. 17 (suppl.): 10–11 (1970)
Bardele, C.F.: Cell cycle, morphogenesis and ultrastructure in the pseudoheliozoan Clathrulina elegans. Z. Zellforsch. 130, 219–242 (1972)
Bardele, C.F.: The fine structure of the centrohelidan heliozoan Heterophrys marina. Cell Tiss. Res. 161, 85–102 (1975)
Branton, D.: Freeze-etching nomenclature. Science 190, 54–56 (1975)
Brown, R.M., Jr., Montezinos, D.: Cellulose microfibrils. Visualization and orienting complexes in association with the plasma membrane. Proc. nat. Acad. Sci. (Wash.) 73, 143–147 (1970)
Davidson, L.A.: The development and plasma membrane attachment sites of the haptocyst-like organelles of Heterophrys marina. J. Protozool. 20, 506 (1973)
Davidson, L.A.: An outline of the origin and evolution of the actinopods. J. Protozool. 21, 426 (1974)
Davidson, L.A.: Studies of the actinopods Heterophrys marina and Ciliophrys marina: Energetics and structural analysis of their contractile axopodia, general ultrastructure and phylogenetic relationships. Ph.D. Thesis, University of California at Berkeley (1975).
Dreifuss, J.J., Akert, K., Sandri, C., Moor, H.: Specific arrangements of membrane particles at sites of exo-endocytosis in the freeze-etched neurohypophysis. Cell Tiss. Res. 165, 317–325 (1976)
Edds, R.: Particle movements in artificial exopodia of Echinosphaerium nucleofilum. J. Cell Biol. 59, 88a (1973)
Edidin, M.: Two-dimensional diffusion in membranes. Symp. Soc. exp. Biol. 28, 1–14 (1974)
Edidin, M., Fambrough, D.: Fluidity of the surface of cultured muscle fibers. J. Cell Biol. 57, 27–37 (1973)
Fisher, G.W., Kaneshiro, E.S.: Ultrastructural localization of calcium deposits in cilia of Paramecium aurelia. J. Cell Biol. 67, 115a (1975)
Fitzharris, T.P., Bloodgood, R.A., McIntosh, J.R.: Particle movement in the axopodia of Echinosphaerium: Evidence concerning the role of the exonome. J. Mechanochem. Cell Motility 1, 117–124 (1972)
Franke, W.W., Kartenbeck, J., Zentgraf, H., Scheer, U., Falk, H.: Membrane-to-membrane crossbridges. A means to orientation and interaction of membrane faces. J. Cell Biol. 51, 881–888 (1971)
Frey, L.D., Eddin, M.: The rapid intermixing of cell surface antigens after formation of mousehuman heterokaryons. J. Cell Sci. 7, 319 (1970)
Frey-Wyssling, A.: Comparative organellography of the cytoplasm. Protoplasmatologica III (1973)
Gilula, N.B., Branton, D., Satir, P.: The septate junction: A structural basis for intercellular coupling. Proc. nat. Acad. Sci. (Wash.) 67, 213–220 (1970)
Grell, K.G.: Protozoology. Berlin-Heidelberg-New York: Springer 1973
Hovasse, R.: Trichocystes, corps trichocystoides, cnidocystes et colloblastes. In: Protoplasmatologia (Handbuch der Protoplasmaforschung), Vol. 3, F, pp. 1–57. Wien-New York: Springer 1965
Hovasse, R.L.: Trichocystes ou corps trichocystoides, et nematocystes chez les Protistes. Ann. Stat. Biol. Besse-en-Chamdesse 4, 245–269 (1969)
Janisch, R.: Pellicle of Paramecium caudatum as revealed by freeze etching. J. Protozool. 19, 470–472 (1972)
Leadbeater, B.S.C.: A fine structural study of Olisthodiscus luteus Cater. Brit. Phycol. J. 4, 3–17 (1969)
Luft, J.: Electron microscopy of cell extraneous coats as revealed by ruthenium red staining. J. Cell Biol. 23, 54A (1964)
Plattner, H.L.: Intramembraneous change on cationophore-triggered exocytosis in Paramecium. Nature (Lond.) 252, 722–724 (1974)
Plattner, H., Miller, F., Bachmann, L.: Membrane specializations in the form of regular membraneto-membrane attachment sites in Paramecium. A correlated freeze-etching and ultrathin-sectioning analysis. J. Cell Sci. 13, 687–720 (1973)
Robinson, D.C., Preston, R.D.: Fine structure of swarmers of Cladophora and Chaetomorpha. J. Cell Sci. 9, 581–601 (1971)
Satir, B.: Membrane events during the secretory process. Symp. Soc. exp. Biol. 28, 399–418 (1974)
Satir, B.: The final steps in secretion. Sci. Amer. 233, 28–37 (1975)
Satir, B., Schooley, C., Satir, P.: Membrane reorganization during secretion in Tetrahymena pyriformis. Nature (Lond.) 235, 53–54 (1972)
Satir, B., Schooley, C., Satir, P.: Membrane fusion in a model system: Mucocyst secretion in Tetrahymena. J. Cell Biol. 56, 153–176 (1973)
Swale, E.M.F.: A study of the nannoplankton flagellate Pedinella hexacostata Vysotskii by light and electron microscopy. Brit. Phycol. J. 4, 65–86 (1969)
Tilney, C.G., Porter, K.R.: Studies on microtubules in heliozoa 1. The fine structure of Actinosphaerium nucleofilum (Barrett) with particular reference to the axial rod structure. Protoplasma 60, 317–344 (1965)
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Supported by USPHS GM01021 and HL13849
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Davidson, L.A. Ultrastructure of the membrane attachment sites of the extrusomes of Ciliophrys marina and Heterophrys marina (Actinopoda). Cell Tissue Res. 170, 353–365 (1976). https://doi.org/10.1007/BF00219417
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DOI: https://doi.org/10.1007/BF00219417