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Development and ultrastructure of the marine, parasitic oomycete, Lagenisma coscinodisci Drebes (Lagenidiales)

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The thalli of Lagenisma coscinodisci are coenocytic. In young thalli each nucleus is associated with two procentrioles and four dictyosomes. Before nuclear division two pairs of procentrioles are found on two opposite poles each lying in a pocket of the nuclear membranes. The spindle microtubules radiate from these poles; the nuclear membrane remains completely closed in all divisional stages. The thallus transforms holocarpically into a zoosporangium. The differentiation begins after the breakdown of the host with the formation of a cell wall and with the development of a discharge tube. During these processes peripheral dilated tubules are observed which are in close, local contact with small infoldings of the plasmalemma. The discharge tube develops independent of the point of entry of the infection tube and enlarges by tip growth. There are several light and electron microscopical observations which suggest that the last nuclear divisions in zoosporangia of old cultures are meiotic.

They give rise to sexually determined zoomeiospores.

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  1. Amerson, H. V., Bland, C. E.: The occurrence of polycomplexes in the nucleus of encysting spores of Lagenidium callinectes, a marine Phycomycete. Mycologia 65, 966–970 (1973)

  2. Bryant, T. R., Howard, K. L.: Meiosis in the Oomycetes: I. A microspectrophotometric analysis of nuclear deoxiribonucleic acid in Saprolegnia terrestris. Am. J. Bot. 56, 1075–1083 (1969) (1969)

  3. Christen, J., Hohl, H. R.: Growth and ultrastructural differentiation of sporangia in Phytophthora palmivora. Canad. J. Microbiol. 18, 1959–1964 (1972)

  4. Drebes, G.: Ein parasitischer Phycomycet (Lagenidiales) in Coscinodiscus. Helgol. Wiss. Meeresunters. 13, 426–435 (1966)

  5. Drebes, G.: Lagenisma coscinodisci (Lagenidiales) — Vegetative Vermehrung in der Kieselalge Coscinodiscus granii. Encyclop. cinematogr. E 1398 (1969)

  6. Duff, T., Youatt, J.: Discharge papilla development in the phycomycete Allomyces. Arch. Microbiol. 112, 187–194 (1977)

  7. Ellzey, J. T.: Ultrastructural observations of meiosis within antheridia of Achlya ambisexualis. Mycologia (N.Y.) 66, 32–47 (1974)

  8. Flanagan, P. W.: Meiosis and mitosis in Saprolegniaceae. Canad. J. Bot. 48, 2069–2076 (1970)

  9. Gotelli, D.: The morphology of Lagenidium callinectes. I. Vegetative development. Mycologia (N.Y.) 66, 639–647 (1974a)

  10. Gotelli, D.: The morphology of Lagenidium callinectes. II. Zoosporogenesis. Mycologia (N.Y.) 66, 846–858 (1974b)

  11. Hagedorn, H., Weinert, H.: Die Veränderung der Ultrastruktur während der Zoosporogenese bei Saprolegnia monoica. Protoplasma 81, 145–162 (1974)

  12. Haskins, R. H., Brushaber, J. A., Child, J. J., Holtby, L. B.: The ultrastructure of sexual reproduction in Pythium acanthicum. Canad. J. Bot. 54, 2193–2203 (1976)

  13. Heath, I. B.: Centrioles and mitosis in some Oomycetes. Mycologia (N.Y.) 66, 354–359 (1974a)

  14. Heath, I. B.: Mitosis in the fungus Thraustotheca clavata. J. Cell Biol. 60, 204–220 (1974b)

  15. Heath, I. B.: The effect of antimicrotubule agents on the growth and ultrastructure of the fungus Saprolegnia ferax and their ineffectiveness in disrupting hyphal microtubules. Protoplasma 85, 147–176 (1975)

  16. Heath, I. B., Greenwood, A. D.: Electron microscopic observations of dividing somatic nuclei in Saprolegnia. J. Gen. Microbiol. 53, 287–289 (1968)

  17. Heath, I. B., Greenwood, A. D.: Ultrastructural observations on the kinetosomes, and Golgi bodies during the asexual life cycle of Saprolegnia. Z. Zellforsch. 112, 371–389 (1971)

  18. Hemmes, D. E., Hohl, H. R.: Ultrastructural changes in directly germinating sporangia of Phytophthora parasitica. Am. J. Bot. 56, 300–313 (1969)

  19. Hemmes, D. E., Hohl, H. R.: Mitosis and nuclear degeneration: simultaneous events during secondary sporangia formation in Phytophthora palmivora. Canad. J. Bot. 51, 1673–1675 (1973)

  20. Hoch, H. C., Mitchell, J. E.: The ultrastructure of zoospores of Aphanomyces euteiches and of their encystment and subsequent germination. Protoplasma 75, 113–138 (1972)

  21. Hohl, H. R., Hamamoto, S. T.: Ultrastructural changes during zoospore formation in Phytophthora parasitica. Am. J. Bot. 54, 1131–1139 (1967)

  22. Howard, K. L., Bryant, T. R.: Meiosis in Oomycetes. II. A microspectrophotometric analysis of DNA in Apodachlya brachynema. Mycologia (N.Y.) 63, 58–68 (1971)

  23. Howard, K. L., Moore, R. T.: Ultrastructure in oogenesis in Saprolegnia terrestris. Bot. Gaz. 131, 311–336 (1970)

  24. Khan, S. R.: Electron microscopic observations of dividing somatic nuclei in Albugo. Canad. J. Bot. 54, 168–172 (1976)

  25. Lunney, C. Z., Bland, C. E.: An ultrastructural study of zoosporogenesis in Pythium proliferum de Bary. Protoplasma 88, 85–100 (1976)

  26. Manier, J.-F.: Cycle et ultrastructure de Blastulidium poedophthorum Pérez 1903 (Phycomycète Lagénidiale) parasite des oeufs de Simocephalus vetulus (Mull.) Schoedler (Crustacé, Cladocère). Protistologica 12, 225–238 (1976)

  27. Schnepf, E., Deichgräber, G., Drebes, G.: Development and ultrastructure of the marine, parasitic oomycete, Lagenisma coscinodisci Drebes (Lagenidiales). The infection. Arch. Microbiol. 116, 133–139 (1978)

  28. Schnepf, E., Drebes, G.: Über die Entwicklung des marinen parasitischen Phycomyceten Lagenisma coscinodisci (Lagenidiales). Helgol. Wiss. Meeresunters. 29, 291–301 (1977)

  29. Sparrow, F. K. Z.: Aquatic Phycomycetes, 2nd ed. Ann Arbor: Univ. Mich. Press 1960

  30. Williams, W. T., Webster, R. K.: Electron microscopy of the sporangium of Phtophthora capsici. Canad. J. Bot. 48, 221–227 (1970)

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Correspondence to E. Schnepf.

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Schnepf, E., Deichgräber, G. & Drebes, G. Development and ultrastructure of the marine, parasitic oomycete, Lagenisma coscinodisci Drebes (Lagenidiales). Arch. Microbiol. 116, 141–150 (1978). https://doi.org/10.1007/BF00406029

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Key words

  • Lagenisma
  • Ultrastructure of the thallus
  • Mitosis
  • Meiosis
  • Wall formation
  • Discharge tube
  • Light and electron microscopy