Kappa organism

from Wikipedia, the free encyclopedia

A kappa organism or kappa particle is what biology calls hereditary cytoplasmic symbionts (endosymbionts), which occur in some strains of the ciliate Paramecium ( paramecium ). Paramecium strains with these particles are called "killer Paramecia". They release a substance called paramecin into the culture medium, which is lethal to kappa particle-free Paramecium . Kappa particles are found in genotypes of Paramecium aurelia syngen 2 that carry the dominant gene K.

Kappa particles are Feulgen- positive and change color to Giemsa staining after acid hydrolysis . The length of the particles is 0.2-0.5 μm.

For a long time it was unclear about the nature of the kappa particles ( viruses , bacteria , organelles or just a nucleoprotein ). Today we know that the particles are intracellular bacterial symbionts ( Caedibacter taeniospiralis , γ-Proteobacteria ). Caedibacter taeniospiralis contains cytoplasmic protein inclusions , so-called R-bodies, which act as a toxin distribution system.

Individual evidence

  1. ^ TM Sonneborn: Paramecium in modern biology . In: Bios . 21, No. 1, 1950, pp. 31-43.
  2. Tan Takayanagi, Shinji Hayashi: Cytological and Cytogenetical Studies on Paramecium polycaryum. V. Lethal Interactions in Certain Stocks . In: Journal of Eukaryotic Microbiology . 11, No. 1, 1964, pp. 128-132. doi : 10.1111 / j.1550-7408.1964.tb01733.x .
  3. Lawrence E. Henderson's Dictionary of biological terms . Longman Group Ltd., London 1999, ISBN 0-582-22708-9 .
  4. ^ Rieger R. Michaelis A., Green MM: Glossary of genetics and cytogenetics: Classical and molecular . Springer-Verlag, Heidelberg - New York 1976, ISBN 0-387-07668-9 .
  5. ^ CH Brown: Elimination of Kappa Particles from 'Killer' Strains of Paramecium aurelia by Treatment with Chloromycetin . In: Nature . 166, No. 4221, 1950, p. 527. doi : 10.1038 / 166527A0 .
  6. Kappa Particles in MediLexicon
  7. ^ Kappa Particles , in: McGraw-Hill Science & Technology Dictionary
  8. ^ FR Pond, I. Gibson, J. Lalucat, RL Quackenbush: R-body-producing bacteria . In: Microbiological Reviews . 53, No. 1, March 1, 1989, ISSN  0146-0749 , pp. 25-67. PMID 2651865 . PMC 372716 (free full text).
  9. Caedibacter , Caedibacter taeniospiralis , on: NCBI Taxonomy Browser
  10. [Caedibacter], on: Taxonomicon

Web links

See also