1887

Abstract

SUMMARY: Changes in the structure of the myxamoebae involved in the formation of the stalk of the fruiting body, or sorocarp, of were investigated. Observed changes in the ultrastructure relating to cell differentiation include: (i) food vacuoles disappear and autophagic vacuoles take their place after cell aggregation; (2) an inclusion in the mitochondria disappears during the vegetative feeding stages; (3) the decrease in number of an electron-clear vacuole is coincident with the appearance of the ‘prespore’ vacuole in cells of the hind portion of the migrating pseudoplasmodium; (4) while the prespore cells diminish in size and their cytoplasm becomes electron dense during culmination, the myxamoebae destined to form cellular elements of the stalk swell and their cytoplasm finally disintegrates.

The slime coat that encircles the entire pseudoplasmodium remains after fixation and dehydration as a triple-layered membrane resembling cell membranes. At the start of culmination, the initial core of unwalled stalk-forming cells descends through the then vertically oriented cell mass. The polarization of cytoplasm in the horizontally oriented prestalk cells of the apical papilla is described, as well as the formation of the two-layered sheath around the stalk. The mass of so-called rearguard cells of the migrating pseudoplasmodium separates during culmination and a fraction of them form the basal disc while the remainder rise on the stalk just below the prespore mass.

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1972-05-01
2021-08-01
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References

  1. Aschner M., Kogan S. 1959; Observations on the growth of Labyrinthula macrocystis . Bulletin of the Research Council of Israel D 8:15–24
    [Google Scholar]
  2. Ashworth J. M., Dundan D., Rowe A. J. 1969; Changes in fine structure during cell differentiation of the cellular slime mould Dictyostelium discoideum . Experimental Cell Research 58:73–78
    [Google Scholar]
  3. Bonner J. T. 1944; A descriptive study of the development of the slime mold. Dictyostelium discoideum American Journal of Botany 31:175–182
    [Google Scholar]
  4. Bonner J. T., Dodd M. R. 1962; Aggregation territories in the cellular slime molds. Biological Bulletin of the Marine Biological Laboratory, Woods Hole 122:13–24
    [Google Scholar]
  5. Bonner J. T., Slifkin M. K. 1949; A study of the control of differentiation: the proportions of stalk and spore cells in the slime mold Dictyostelium discoideum . American Journal of Botany 36:727–734
    [Google Scholar]
  6. Bowers B., Korn E. D. 1969; The fine structure of Acanthamoeba castellanii (Neff strain). II. Encyst-ment. Journal of Cell Biology 41:786–805
    [Google Scholar]
  7. Cotter D. A., Miura-Santo L. Y., Hohl H. R. 1969; Ultrastructural changes during germination of Dictyostelium discoideum spores. Journal of Bacteriology 100:1020–1026
    [Google Scholar]
  8. George R. P. 1969; Radioautography of stalk formation in a cellular slime mold. Journal of Cell Biology 43:98A
    [Google Scholar]
  9. George R. P., Albrecht R. M., Raper K. B., Sachs I. B., Mackenzie A. P. 1970; Rapid freeze preparation of Dictyostelium discoideum for scanning electron microscopy. Proceedings Third Annual Stereoscan Colloquium3 pp 159–165 Morton Grove, Illinois: Kent-Cambridge Co;
    [Google Scholar]
  10. George R. P., Hohl H. R. 1969; Electron microscopy of crystalline micelles in cellulose elementary fibrils of Dictyostelium discoideum . Planta 88:67–72
    [Google Scholar]
  11. Gezelius K. 1961; Further studies in the ultrastructure of Acrasiae . Experimental Cell Research 23:300–310
    [Google Scholar]
  12. Gezelius K., Rånby B. G. 1957; Morphology and fine structure of the slime mold Dictyostelium discoideum . Experimental Cell Research 12:265–289
    [Google Scholar]
  13. Gregg J. H., Badman W. A. 1970; Morphogenesis and ultrastructure in Dictyostelium . Developmental Biology 22:96–111
    [Google Scholar]
  14. Hohl H. R. 1965; Nature and development of membrane systems in food vacuoles of cellular slime molds predatory upon bacteria. Journal of Bacteriology 90:755–765
    [Google Scholar]
  15. Hohl H. R., Hamamoto S. T. 1969a; Ultrastructure of spore differentiation in Dictyostelium: the prespore vacuole. Journal of Ultrastructure Research 26:442–453
    [Google Scholar]
  16. Hohl H. R., Hamamoto S. T. 1969b; Ultrastructure of Acrasis rosea, a cellular slime mold during development. Journal of Protozoology 16:333–344
    [Google Scholar]
  17. Hohl H. R., Hamamoto S. T., Hemmes D. E. 1968; Ultrastructural aspects of cell elongation, cellulose synthesis and spore differentiation in Acytostelium leptosomum, a cellular slime mold. American Journal of Botany 55:783–796
    [Google Scholar]
  18. Hohl H. R., Miura-Santo L. Y., Cotter D. A. 1970; Ultrastructural changes during formation and germination of microcysts in Polysphondylium pallidum, a cellular slime mold. Journal of Cell science 7:285–305
    [Google Scholar]
  19. Hohl H. R., Raper K. B. 1964; Control of sorocarp size in the cellular slime mold Dictyostelium discoideum . Developmental Biology 9:137–153
    [Google Scholar]
  20. Kirk D., McKeen W. E., Smith R. 1971; Cytoplasmic connections between Dictyostelium discoideumcells. Canadian Journal of Botany 49:19–20
    [Google Scholar]
  21. Maeda Y., Takeuchi I. 1969; Cell differentiation and fine structures in the development of the cellular slime molds. Development, Growth and Differentiation 11:232–245
    [Google Scholar]
  22. Mercer E. H., Shaffer B. M. 1960; Electron microscopy of solitary and aggregated slime mold cells-. Journal of Biophysical and Biochemical Cytology 7:353–356
    [Google Scholar]
  23. Mühlethaler K. 1956; Electron microscopic study of the slime mold Dictyostelium discoideum . American Journal of Botany 43:673–678
    [Google Scholar]
  24. Porter D. 1969; Ultrastructure of Labyrinthula . Protoplasm 67:1–20
    [Google Scholar]
  25. Raper K. B. 1941; Developmental patterns in simple slime molds. Third Growth Symposium 5:41–76
    [Google Scholar]
  26. Raper K. B., Fennell D. I. 1952; Stalk formation in Dictyostelium . Bulletin of the Torrey Botanical Club 79:25–51
    [Google Scholar]
  27. Reynolds E. S. 1963; The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. Journal of Cell Biology 17:208–212
    [Google Scholar]
  28. schäfer-Danneel S. 1967; Strukturelle und funktionelle Yoraussetzungen für die Bewegung von Amoeba proteus . Zeitschrift für Zell forschung und mikroskopische Anatomie 78:441–462
    [Google Scholar]
  29. Stey H. 1969; Elektronenmikrosopische Untersuchung an Labyrinthula coenocystis schmoller. Zeitschrift für Zellforschung und mikroskopische Anatomie 102:387–418
    [Google Scholar]
  30. Sussman M., Lovgren N. 1965; Preferential release of the enzyme UDP-galactose polysaccharide transferase during cellular differentiation in the slime mold Dictyostelium discoideum . Experimental Cell Research 38:97–105
    [Google Scholar]
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