In biology, Kappa organism or Kappa particle refers to inheritable cytoplasmic symbionts, occurring in some strains of the ciliate Paramecium. Paramecium strains possessing the particles are known as "killer paramecia". They liberate a substance also known as paramecin [1] [2] into the culture medium that is lethal to Paramecium that do not contain kappa particles. Kappa particles are found in genotypes of Paramecium aurelia syngen 2 that carry the dominant gene K. [3] [4]
Kappa particles are Feulgen-positive and stain with Giemsa after acid hydrolysis. The length of the particles is 0.2–0.5μ. [5]
While there was initial confusion over the status of kappa particles as viruses, bacteria, organelles, [6] or mere nucleoprotein, [7] the particles are intracellular bacterial symbionts called Caedibacter taeniospiralis. [8] Caedibacter taeniospiralis contains cytoplasmic protein inclusions called R bodies which act as a toxin delivery system.
References
- ^ Sonneborn, T. M. (1950). "Paramecium in modern biology". BIOS. 21 (1): 31–43.
- ^ Takayanagi, Tan; Hayashi, Shinji (1964). "Cytological and Cytogenetical Studies on Paramecium polycaryum. V. Lethal Interactions in Certain Stocks". Journal of Eukaryotic Microbiology. 11 (1): 128–132. doi: 10.1111/j.1550-7408.1964.tb01733.x. PMID 14119554.
- ^ Lawrence E. (1999). Henderson's Dictionary of biological terms. London: Longman Group Ltd. ISBN 0-582-22708-9.
- ^ Rieger R. Michaelis A.; Green M. M. (1976). Glossary of genetics and cytogenetics: Classical and molecular. Heidelberg - New York: Springer-Verlag. ISBN 0-387-07668-9.
- ^ Brown, C. H. (1950). "Elimination of Kappa Particles from 'Killer' Strains of Paramecium aurelia by Treatment with Chloromycetin". Nature. 166 (4221): 527. Bibcode: 1950Natur.166..527B. doi: 10.1038/166527A0. PMID 14780133.
- ^ Kappa Particles in mediLexicon
- ^ Kappa Particles in McGraw-Hill Science & Technology Dictionary
- ^ Pond, F. R.; Gibson, I.; Lalucat, J.; Quackenbush, R. L. (1989-03-01). "R-body-producing bacteria". Microbiological Reviews. 53 (1): 25–67. doi: 10.1128/mr.53.1.25-67.1989. ISSN 0146-0749. PMC 372716. PMID 2651865.
External links
- Preer, L. B.; Jurand, A.; Preer Jr, J. R.; Rudman, B. M. (1972). "The classes of kappa in Paramecium aurelia". Journal of Cell Science. 11 (2): 581–600. doi: 10.1242/jcs.11.2.581. PMID 5076362.
- Preer Jr, J. R.; Preer, L. B.; Jurand, A. (1974). "Kappa and other endosymbionts in Paramecium aurelia". Bacteriological Reviews. 38 (2): 113–163. doi: 10.1128/br.38.2.113-163.1974. PMC 413848. PMID 4599970.
See also
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