Summary
InStephanoeca diplocostata microtubules are located in four positions namely: within the flagellar axoneme; just beneath the plasmalemma; associated with the silica deposition vesicles (SDVs) during early stages of costal strip deposition; and in the mitotic spindle. At the anterior end of the cell the 50–60 peripheral microtubules, which are organized more or less parallel to the long axis of the cell, converge around the base of the emergent flagellum. A short second flagellar base is positioned between the nucleus and the base of the emergent flagellum. Developing costal strips are located individually within SDVs in the peripheral cytoplasm. During the early stages of silica deposition each SDV is curved and subtended longitudinally on its concave side by two microtubules. When a costal strip has achieved sufficient rigidity to withstand bending the SDV-associated microtubules are depolymerized. Treatment of exponentially growing cells with sublethal concentrations of microtubule poisons, such as colchicine, podophyllotoxin, griseofulvin andVinca alkaloids depresses growth. Treatment with these drugs also affects the length and morphology of developing costal strips perhaps by interfering with the shaping and supporting functions of SDV-associated microtubules. Instead of being long and crescentic with a standard radius of curvature, costal strips of treated cells are usually short and misshapen, with irregular bends. After drug treatment, juveniles produced as a result of cell division do not develop flagella but can still assemble a lorica although it is usually misshapen. The role of microtubules and microfilaments in lorica production is discussed.
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References
Blank GS, Sullivan CW (1983 a) Diatom mineralisation of silicic acid. VI. The effects of microtubule inhibitors on silicic acid metabolism inNavicula saprophila. J Phycol 19: 39–44
— — (1983 b) Diatom mineralisation of silicic acid. VII. Influence of microtubule drugs on symmetry and pattern formation in valves ofNavicula saprophila during morphogenesis. J Phycol 19: 294–301
Brown DL, Bouck GB (1973) Microtubule biogenesis and cell shape inOchromonas. II. The role of nucleating sites in shape development. J Cell Biol 56: 360–378
Brugerolle G, Bricheux G (1984) Actin microfilaments are involved in scale formation of the chrysomonad cellSynura. Protoplasma 123: 203–212
Bryan J (1972) Definition of three classes of binding sites in isolated microtubule crystals. Biochemistry 11: 2611–2615
Collis PS, Weeks DP (1978) Selective inhibition of tubulin synthesis by amiprophosmethyl during flagellar regeneration inChlamydomonas reinhardi. Science 202: 440–442
Cortese F, Bhattacharyya B, Wolff J (1977) Podophyllotoxin as a probe for the colchicine-binding site of tubulin. J Biol Chem 252: 1134–1140
Crawford RM, Schmid AM (1986) Ultrastructure of silica deposition in diatoms. In:Leadbeater BSC, Riding R (eds) Biomineralization in lower plants and animals. Oxford University Press, Oxford, pp 292–314
Dustin P (1978) Microtubules. Second edition. Springer, Berlin Heidelberg New York, pp 1–482
Hertel C, Quader H, Robinson DG, Marme D (1980) Antimicrotubular herbicides and fungicides affect Ca2+ transport in plant mitochondria. Planta 149: 336–340
Hess FD, Bayer DE (1977) Binding of the herbicide trifluralin toChlamydomonas flagellar tubulin. J Cell Sci 24: 351–360
Hibberd DJ (1975) Observations on the ultrastructure of the choanoflagellateCodosiga botrytis (Ehr.) Saville Kent with special reference to the flagellar apparatus. J Cell Sci 17: 191–219
Kiermayer O, Fedtke C (1977) Strong anti-microtubule action of amiprophos-methyl (APM) inMicrasterias. Protoplasma 92: 163–166.
Laval M (1971) Ultrastructure et mode de nutrition du choanoflagelléSalpingoeca pelagica sp. nov. Comparison avec les choanocytes des spongiares. Protistologica 7: 325–336
Leadbeater BSC (1979 a) Developmental studies on the loricate choanoflagellateStephanoeca diplocostata Ellis. I. Ultrastructure of the non-dividing cell and costal strip production. Protoplasma 98: 241–262
— (1979 b) Developmental studies on the loricate choanoflagellateStephanoeca diplocostata Ellis. II. Cell division and lorica assembly. Protoplasma 98: 311–328
— (1983 a) Distribution and chemistry of microfilaments in choanoflagellates, with special reference to the collar and other tentacle systems. Protistologica 19: 157–166
— (1983 b) Life-history and ultrastructure of a new marine species ofProterospongia (Choanoflagellida). J mar biol Ass UK 63: 135–160
— (1984) Silicification of “cell walls” of certain protistan flagellates. Phil Trans R Soc Lond B 304: 529–536
— (1985) Developmental studies on the loricate choanoflagellateStephanoeca diplocostata Ellis. IV. Effects of silica deprivation on growth and lorica production. Protoplasma 127: 171–179
—,Davies ME (1984) Developmental studies on the loricate choanoflagellateStephanoeca diplocostata Ellis. III Growth and turnover of silica, preliminary observations. J Exp Mar Biol Ecol 81: 251–268
—,Morton C (1974) A microscopical study of a marine species ofCodosiga James Clark (Choanoflagellata) with special reference to the ingestion of bacteria. Biol J Linn Soc 6: 337–347
Mignot JP, Brugerolle G (1982) Scale formation in chrysomonad flagellates. J Ultrastruct Res 81: 13–26
Pickett-Heaps JD, Tippit DH, Andreozzi JA (1979) Cell division in the pennate diatomPinnularia. IV. Valve morphogenesis. Biol Cellulaire 35: 199–206
Quader H, Filner P (1980) The action of antimitotic herbicides on flagellar regeneration inChlamydomonas reinhardi: a comparison with action of colchicine. Eur J Cell Biol 21: 301–304
Rosenbaum JL, Carlson A (1969) Cilia regeneration inTetrahymena and inhibition by colchicine. J Cell Biol 40: 415–425
—,Moulder JE, Ringo DL (1969) Flagellar elongation and shortening inChlamydomonas. The use of cycloheximide and colchicine to study the synthesis and assembly of flagellar proteins. J Cell Biol 41: 600–619
Schmid AM (1980) Valve morphogenesis in diatoms. A pattern related filamentous system in pennates and the effect of APM, colchicine and osmotic pressure. Nova Hedwigia 33: 811–847
—,Borowitzka MA, Volcani BE (1981) Morphogenesis and biochemistry of diatom cell walls. In:Kiermayer O (ed) Cytomorphogenesis in plants. Cell Biol Monogr 8. Springer, Wien New York, pp 63–77
Schnepf E, DeichgrÄber G (1969) über die Feinstruktur vonSynura petersenii unter besonderer Berücksichtigung der Morphogenese ihrer Kieselschuppen. Protoplasma 68: 85–106
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Leadbeater, B.S.C. Developmental studies on the loricate choanoflagellateStephanoeca diplocostata Ellis. V. The cytoskeleton and the effects of microtubule poisons. Protoplasma 136, 1–15 (1987). https://doi.org/10.1007/BF01276313
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DOI: https://doi.org/10.1007/BF01276313