Summary
Methods are described for the collection, treatment and uniform discharge of large quantities of gametes, and a measure of fertilization control in the monoecious brown alga, Fucus distichus. Fertilization was examined using the techniques of blister-formation, gamete separation experiments, and electron microscopy. Sperm enter the freshly-discharged egg packets through a mesochite pore and juxtaposition with the eggs early. However, experimental and thinsection data indicate that fertilization does not occur until the eggs dissociate from the mesochite and round up. Hence, the egg surface appears to undergo three functional changes following its release from the thallus: (1) a pre-dissociation state which inhibits fertilization within the mesochite; (2) a dissociation state when fusion of gametes is possible; and (3) a post-fertilization state characterized by the formation of extraneous coats. As the egg is activated by the sperm a nonmembranous layer appears to detach from the egg surface to form an activation layer. This is augmented by fibrous units to function as a fertilization barrier which ultimately thickens to form the cell wall. The area between the eggs within the egg packet is characterized by the presence of fibrous and particulate substances which are continuously given off through the egg surface. These apparently play a functional role in the sequential stages of fertilization in Fucus. These observations are discussed in terms of analogies with fertilization in the sea urchin.
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References
Anderson, E.: Oocyte differentiation in the sea urchin, Arbacia punctulata, with particular reference to the origin of cortical granules and their participation in the cortical reaction. J. Cell Biol. 37, 514–539 (1968).
Bennett, H. S.: Morphological aspects of extracellular polysaccharides. J. Histochem. Cytochem. 11, 1–14 (1963).
Cook, A. H., Elvidge, J. A.: Fertilization in the Fucaceae: Investigations on the nature of the chemotactic substance produced by the eggs of Fucus serratus and Fucus vesiculosus. Proc. roy. Soc. B 138, 97–114 (1951).
Farmer, J. B., Williams, J. L.: Contributions to our knowledge of the Fucaceae: their life-history and cytology. Phil. Trans. B 190, 623–645 (1898).
Ito, S.: Structure and function of the glycocalyx. Fed. Proc. 28, 12–25 (1969).
Jaffe, L.: Morphogenesis in lower plants. Ann. Rev. Plant Physiol. 9, 359–384 (1958).
—: Localization in the developing Fucus egg and the general role of localizing currents. Advanc. Morphogenes. 7, 295–328 (1968).
Levring, T.: Remarks on the submicroscopical structure of eggs and spermatozoids of Fucus and related genera. Physiol. Plantarum 5, 528–539 (1952).
Machlis, L., Rawitscher-Kunkel, E.: Mechanisms of gametic approach in plants. In: Fertilization, vol. I (C. B. Metz and A. Monroy, eds.), p. 117–162. New York: Acad. Press 1967.
Manton, I., Clarke, B.: Observations with the electron microscope on the internal structure of the spermatozoid of Fucus. J. exp. Bot. 7, 416–432 (1956).
McCully, M. E.: Histological studies on the genus Fucus II. Histology of the reproductive tissues. Protoplasma 66, 205–230 (1968).
Metz, C. B.: Use of inhibiting agents in studies of fertilization mechanisms. Int. Rev. Cytol. 11, 219–253 (1961a).
— Fertilization studies using inhibitors. Germ cells and earliest stages of development (S. Ranz, ed.), p. 175–196. Milan: Fondazione F. Baselle 1961b.
—: Gametic surface components and their role in fertilization. In: Fertilization, vol. I (C. B. Metz and A. Monroy, eds.), p. 163–236. New York: Acad. Press 1967.
Nakazawa, S.: Developmental mechanics of Fucaceous algae VIII. Blister formation in some Fucoid eggs. Bot. Mag. (Tokyo) 71, 23–25 (1958).
Nelson, L.: Sperm motility. In: Fertilization, vol. I (C. B. Metz and A. Monroy, eds.), p. 27–97. New York: Acad. Press 1967.
Pollock, E. G.: Interzonal transplantation of embryos and mature plants of Fucus. Proc. VIth Intern. 1 Symp. on Marine Algae, Santiago de Compostello, Spain 6, 345–356 (1968).
Reynolds, E. S.: The use of lead citrate at high pH as an electron opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Thuret, G.: Recherches sur la fecondation des Fucaceae. Ann. Sci. Nat. Bot., Sér. IV 2, 197–214 (1854).
Torrey, J. G.: Development in flowering plants. New York: Macmillan 1967.
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This work was supported by a Lalor Foundation Research Fellowship at Friday Harbor Biological Laboratories, University of Washington, and by a National Science Foundation Science Faculty Fellowship to the Swiss Federal Institute of Technology, Zürich, Switzerland.
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Pollock, E.G. Fertilization in Fucus . Planta 92, 85–99 (1970). https://doi.org/10.1007/BF00385566
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DOI: https://doi.org/10.1007/BF00385566