Plasmodium (life cycle)

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For the genus of parasitic protozoa, which causes malaria, see Plasmodium.
Plasmodiocarp of the slime mold Hemitrichia serpula: the living structure contains many nuclei, not separated from each other by cell membranes or cell walls.

A plasmodium is a living structure of cytoplasm that contains many nuclei, rather than being divided into individual cells each with a single nucleus.

Plasmodia are best known from slime molds, but are also found in parasitic Cnidospora, and some algae such as the Chlorarachniophyta.

Structure[edit]

A plasmodium is an amoeboid, multinucleate and naked mass of cytoplasm that contains many diploid nuclei. The resulting structure, a coenocyte, is created by many nuclear divisions without the process of cytokinesis which in other organisms pulls newly-divided cells apart.[1]

Taxonomic distribution[edit]

The term plasmodium usually refers to the feeding stage of slime molds; these are macroscopic myxomycetes.[2]

The multinucleate developmental stages of some intracellular parasites, namely Microsporidia (now in Fungi) and Myxosporidia (now in Cnidaria), former cnidosporans, are also sometimes called plasmodia.[3]

Similarly, in Rhizaria, the ameboid, multinucleate protoplasts of some Cercozoan algae, e.g. Chlorarachniophyta, are called plasmodia. These lack cell walls; the syncytia are created by cell fusion.[3] Some plasmodiophorids and haplosporidians are other multinucleated rhizarians.[4]

References[edit]

  1. ^ Sharma OP. (1988). "4. Myxomycota". Textbook of Fungi. Boston: McGraw Hill Higher Education. pp. 33–48. ISBN 0-07-460329-9. Retrieved January 31, 2013. 
  2. ^ Berg, Linda (2008). Introductory Botany: Plants, People, and the Environment (2nd ed.). Belmont CA: Thomson Corporation. p. 398. ISBN 0-03-075453-4. 
  3. ^ a b Hoek, C. van den, Mann, D.G. and Jahns, H.M. (1995). Algae An Introduction to Phycology. Cambridge University Press, Cambridge. ISBN 0-521-30419-9.
  4. ^ Brown MW, Kolisko M, Silberman JD, Roger AJ. (2012). Aggregative Multicellularity Evolved Independently in the Eukaryotic Supergroup Rhizaria. Current Biology, Volume 22, Issue 12, 1123-1127.