Summary
Zoosporogenesis inLagenisma begins after the final nuclear division by the development of “encystment vesicles” which presumably are derived from Golgi vesicles. The sporangial wall is secreted simultaneously. Initially, the encystment vesicles have an internal coat of fine ribs which becomes a uniform mass during the complicated invagination of the vesicles. When the sporangial wall is complete the protoplast cleaves centripetally by means of narrow “cleavage cisternae” apparently coming from the distal face of the dictyosomes and being detached by interposing ER cisternae. The cleavage cisternae fuse with each other and with the plasmalemma to which they are often parallel. Narrow cytoplasmic compartments are then cut off and swell to become “separation vesicles” which lie between the developing zoospores but later disintegrate. Basal bodies develop from procentrioles after the final nuclear division and elongate into flagella (without participation of a flagellar vesicle) when cleavage is complete. The mastigonemes are formed within the ER, mature within the peripheral elements of the dictyosomes near the flagellar bases and appear to be extruded after the elongation of the flagellum. Structurally, especially in the organization of the flagellar root apparatus, the zoospores resemble primary zoospores of other Oomycetes. They become motile within the zoosporangium but seem to be driven out by means of additional unknown forces.—Formation of the encystment vesicles and the manner of cleavage are compared with those of other Oomycetes and general aspects ofLagenisma zoosporogenesis are discussed.
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References
Berlin, J. D., andC. C. Bowen, 1964: Centrioles in the fungusAlbugo candida. Amer. J. Bot.51, 650–652.
Bimpong, C. E., andC. J. Hickman, 1975: Ultrastructural and cytochemical studies of zoospores, cysts, and germinating cysts ofPhytophthora palmivora. Canad. J. Bot.53, 1310–1327.
Bland, C. E., andH. V. Amerson, 1973: Electron microscopy of zoosporogenesis in the marine phycomyceteLagenidium callinectes Couch. Arch. Mikrobiol.94, 47–64.
Borkowski, M., 1970: Zum Verhalten von Fremdzellen in entleerten Zoosporangien des PhycomycetenSaprolegnia. Biochem. Physiol. Pfl.161, 33–41.
Bouck, G. B., 1971: The structure, origin, isolation, and composition of the tubular mastigonemes of theOchromonas flagellum. J. Cell Biol.50, 362–384.
Bracker, C. E., 1968: The ultrastructure and development of sporangia inGilbertella persicaria. Mycologia60, 1016–1067.
Christen, J., andH. R. Hohl, 1972: Growth and ultrastructural differentiation of sporangia inPhytophthora palmivora. Canad. J. Microbiol.18, 1959–1964.
Drebes, G., 1969:Lagenisma coscinodisci (Lagenidiales) — Vegetative Vermehrung in der KieselalgeCoscinodiscus granii. Encyclop. cinematogr. E. 1398.
Esser, K., 1976: Kryptogamen. Blaualgen, Algen, Pilze, Flechten. Berlin-Heidelberg-New york: Springer.
Gäumann, E., 1964: Die Pilze. 2nd ed. Basel-Stuttgart: Birkhäuser.
Gay, J. L., A. D. Greenwood, andI. B. Heath, 1971: The formation and behaviour of vacuoles (vesicles) during oosphere development and zoospore germination inSaprolegnia. J. gen. Microbiol.65, 233–241.
Gotelli, D., 1974: The morphology ofLagenidium callinectes. II. Zoosporogenesis. Mycologia66, 846–858.
Hagedorn, H., undH. Weinert, 1972: Das endoplasmatische Reticulum während der Sporogenese vonSaprolegnia monoica. Arch. Mikrobiol.81, 13–24.
— —, 1974: Die Veränderung der Ultrastruktur während der Zoosporogenese beiSaprolegnia monoica. Protoplasma81, 145–162.
Heath, I. B., andA. D. Greenwood, 1970: Wall formation in theSaprolegniales. II. Formation of cysts by the zoospores ofSaprolegnia andDictyuchus. Arch. Mikrobiol.75, 67–79.
— —, andH. B. Griffiths, 1970: The origin of flimmer inSaprolegnia, Dictyuchus, Synura andCryptomonas. J. Cell Sci.7, 445–461.
Heintz, C. E., 1970: Zoosporogenesis inPythium middletonii. Amer. J. Bot.57, 760.
Hemmes, D. E., andO. K. Ribeiro, 1977: Electron microscopy of early gamatengial interaction inPhytophthora megasperma var.sojae. Canad. J. Bot.55, 436–447.
Hoch, H. C., andJ. E. Mitchell, 1972 a: The ultrastructure ofAphanomyces euteiches during asexual spore formation. Phytopathology62, 149–160.
— —, 1972 b: The ultrastructure of zoospores ofAphanomyces euteiches and of their encystment and subsequent germination. Protoplasma75, 113–138.
— —, 1975: Further observations on the mechanisms involved in primary spore cleavage inAphanomyces euteiches. Canad. J. Bot.53, 1085–1091.
Hohl, H. R., andS. T. Hamamoto, 1967: Ultrastructural changes during zoospore formation inPhytophthora parasitica. Amer. J. Bot.54, 1131–1139.
Holloway, S. A., andI. B. Heath, 1977: An ultrastructural analysis of the changes in organelle arrangement and structure between the various spore types ofSaprolegnia. Canad. J. Bot.55, 1328–1339.
Loiseaux, S., 1973: Ultrastructure of zoidogenesis in unilocular zoidocysts of several brownalgae. J. Phycol.9, 277–289.
Lunney, C. Z., andC. E. Bland, 1976 a: An ultrastructural study of zoosporogenesis inPythium proliferum de Bary. Protoplasma88, 85–100.
— —, 1976 b: Ultrastructural observations of mature and encysting zoospores ofPythium proliferum de Bary. Protoplasma90, 119–137.
Manier, J.-F., 1976: Cycle et ultrastructure deBlastulidium poedophthorum Pérez 1903 (Phycomycète Lagénidiale) parasite des oeufs deSimocephalus vetulus (Mull.) Schoedler (Crustacé, Cladocére). Protistologica12, 225–238.
Reichle, R. E., 1969: Fine structure ofPhytophthora parasitica zoospores. Mycologia61, 30–51.
Schnepf, E., G.Deichgräber, and G.Drebes, 1978 a: Development and ultrastructure of the marine, parasitic oomycete,Lagenisma coscinodisci Drebes (Lagenidiales): The infection. Arch. Microbiol.116 (in press).
- - - 1978 b: Development and ultrastructure of the marine, parasitic oomycete,Lagenisma coscinodisci Drebes (Lagenidiales): Thallus, zoosporangium, mitosis and meiosis. Arch. Microbiol.116 (in press).
- - - 1978 c: Development and ultrastructure of the marine, parasitic oomycete,Lagenisma coscinodisci Drebes (Lagenidiales): The primary cyst. Canad. J. Bot. (submitted).
—, undG. Drebes, 1977: Uber die Entwicklung des marinen parasitischen PhycomycetenLagenisma coscinodisci (Lagenidiales). Helgol. wiss. Meeresunters.29, 291–301.
Slifkin, M. K., 1967: Nuclear division inSaprolegnia as revealed by colchicine. Mycologia59, 431–445.
Williams, W. T., andR. K. Webster, 1970: Electron microscopy of the sporangium ofPhytophthora capsici. Canad. J. Bot.48, 221–227.
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Schnepf, E., Deichgräber, G. & Drebes, G. Development and ultrastructure of the marine, parasitic Oomycete,Lagenisma coscinodisci Drebes (Lagenidiales): Formation of the primary zoospores and their release. Protoplasma 94, 263–280 (1978). https://doi.org/10.1007/BF01276776
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DOI: https://doi.org/10.1007/BF01276776