Summary
Discophrya collini is a suctorian protozoan with contractile tentacles containing a microtubule-lined canal and microfilaments. The effects of a range of cations on tentacle contraction and ultrastructure have been determined. Treatment with 80 mM CaCl2 and 95 mM MgCl2 causes contraction to 28% and 57% of the control length respectively. Re-extension takes over 4 hours in the culture medium, but CaCl2-treated tentacles are re-extended after a 5 minutes treatment with 10−2 M EDTA or 5 × 10−3 M EGTA. CuCl2 causes a significant contraction at 10−5 M (to 77%); LaCl3 at 10−4 M (to 65%); ZnCl2 at 10−2 M (to 65%), but BaCl2, CoCl2, MnCl2, NiCl2, and SrCl2 cause significant changes only at 10−1 M.
The cytoplasm of CaCl2-treated cells contains two forms of membraneous structures when viewed in TEM; that of MgCl2-treated cells reveals granular areas of medium electron density. None of these features are seen in control cells. The microtubules of the tentacle canal appear to be intact upon its retraction into the cell with no change occurring in the numbers or relative positions of the microtubules. The tentacle cortex is wrinkled. It is suggested from this and previous work that tentacle contraction may be mediated by a microfilament-based mechanism, and that calcium may be involved.
Similar content being viewed by others
References
Bruce, D. L., Marshall, J. M., 1965: Some ionic and bioelectric properties of the amoebaChaos chaos. J. gen. Physiol.49, 151–178.
Curry, A., Butler, R. D., 1976: The ultrastructure, function and morphogenesis of the tentacle inDiscophrya sp. (Suctorida, Cileatea). J. Ultrastruct. Res.56, 164–176.
Eckert, R., 1972: Bioelectric control of ciliary activity-locomotion in the ciliated protozoa is regulated by membrane-limited calcium fluxes. Science176, 473–481.
Geldard, B., 1977: Cytological and physiological studies ofDendrocometes paradoxus (Stein). Ph.D. Thesis, University of Manchester.
Gingell, D., Garrod, D. R., Palmer, J. F., 1970: Divalent cations and cell adhesions. In: Symposium on calcium and cellular function (Cuthbert, A. W., ed.), pp. 59–64. London: Macmillan.
Hackney, C. M., Butler, R. D., 1981 a: A reactivatable glycerol model of tentacle contraction inDiscophrya collini, and the localization of HMM-binding filaments. J. Cell Sci.47, 65–75.
— —, 1981 b: Electrically-induced retraction in the suctorian protozoanDiscophrya collini (Root). J. Protozool.28, 151–157.
— —, 1981 c: Distribution of calcium in the suctorian protozoan,Discophrya collini: an X-ray microanalytical study. Tissue and Cell13, 453–459.
Hauser, M., van Eys, M., 1976: Microtubules and associated microfilaments in the tentacle of the suctorianHeliophrya erhardi Matines. J. Cell Sci.20, 589–617.
Hille, B., Woodhull, A. M., Shapiro, B. I., 1975: Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH. Phil. Trans. R. Soc.B270, 301–318.
Hyams, J. S., Borisy, G. G., 1975: The dependence of the waveform and direction of beat ofChlamydomonas flagella on calcium ions. J. Cell Biol.67, 186 a.
Jones, A. R., Jahn, T. L., Fonseca, J. R., 1966: Contraction of protoplasm. I. Cinematographic analysis of the anodally stimulated contraction ofSpirostomum ambiguus. J. Cell Physiol.68, 127–133.
Lee, H.-C, Auersperg, N., 1980: Calcium in epithelial cell contraction. J. Cell Biol.85, 325–336.
Naitoh, Y., Eckert, R., 1968: Electrical properties ofParamecium caudatum. Modification by bound and free cations. Z. vergl. Physiol.61, 427–452.
Okajima, A., 1957: Protoplasmic contraction observed on the tentacles of the suctorian. I. Effects of electrolytes in the medium. Annot. Zool. Japonensis.30, 51–62.
Pitelka, D. R., 1970: Ciliate ultrastructure: some problems in cell biology. J. Protozool.17, 1–10.
Railkin, A. I., Seravin, L. N., 1981: Influence of nickel, cobalt and lanthanum ions on the mobility and contractility of unicellular organisms. Progress in Protozoology, Abst.303, VI. Int. Congr. Protozool., Warsaw.
Roth, L. E., Shigenaka, Y., 1970: Microtubules in the heliozoan axopodium II. Rapid degradation by cupric and nickelous ions. J. Ultrastruct. Res.31, 356–374.
Rüegg, J. C., 1968: Contractile mechanisms of smooth muscle. Symposium of the Society of experimental Biology22, 45–66.
Sabri, A. W., 1977: Cytological studies of suctorian protozoa. Ph.D. Thesis, University of Manchester.
Schmidt, J. A., Eckert, R., 1976: Calcium couples flagellar reversal to photostimulation inChlamydomonas reinhardii. Nature262, 713–715.
Tsuchiya, T., Takahashi, K., 1976: Localization of possible calcium binding sites in the cilia ofParamecium caudatum. J. Protozool.23, 523–526.
Williams, R. J. P., 1976: Calcium chemistry and its relation to biological function. Symposium of the Society of experimental. Biology30, 1–17.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hackney, C.M., Al-Khazzar, A.R. & Butler, R.D. Tentacle contraction and ultrastructure inDiscophrya collini: The response to cations. Protoplasma 112, 92–100 (1982). https://doi.org/10.1007/BF01280219
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01280219