Centrosome

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Optical section through two mouse cell nuclei in prophase. The nuclear envelope (blue), microtubules (green) and the condensed chromosomes (red) are colored by immunostaining . A centrosome can be seen at the top right . The scale bar corresponds to 5 µm.

The centrosome , also called centrosome or central body , is a cell organelle about 1 µm in size that organizes the mitotic spindle in most animal cells and thus an MTOC ( microtubule organizing center ). It was in 1888 by Edouard Van Beneden discovered and Theodor Boveri named in 1888 and described as "special organ for cell division."

The centrosome is a noticeable region in the cytosol , which is usually found in the middle and near the cell nucleus. It consists of a pair of cylindrical centrioles arranged at right angles to one another , which are embedded in a protein matrix , the pericentriolar matrix. The duplication of the centrosome (centrosome cycle) takes place in coordination with the duplication of the chromosomes (chromosome cycle) during the DNA synthesis phase (S phase). The molecular mechanism of centrosome duplication is not yet known, in any case a daughter centriol must grow out on each of the two mother centrioles, which ultimately leads to two complete centrosomes ( semiconservative replication ).

Before mitosis begins , the two centrosomes separate and migrate to opposite poles of the cell. Each centrosome - each containing a pair of centrioles - is the starting point of a large number of microtubules that make up the mitotic spindle apparatus . After the nucleus and cells have divided, each daughter cell then receives one of the two centrosomes.

Plant cells generally do not contain centrosomes. In higher plants ( angiosperms ) they are basically absent.

Web links

Commons : Centrosome  - collection of images, videos and audio files

Individual evidence

  1. ^ V. Wunderlich: JMM - past and present. Chromosomes and cancer: Theodor Boveri's predictions 100 years later. In: Journal of Molecular Medicine . Volume 80, Number 9, September 2002, pp. 545-548, ISSN  0946-2716 . doi : 10.1007 / s00109-002-0374-y . PMID 12226736 .
  2. ^ Theodor Boveri: Cell studies II: The fertilization and division of the egg of Ascaris megalocephala. Gustav Fischer Verlag, Jena 1888.
  3. Alberts et al .: Molecular biology of the cell. 5th edition, Garland Science, New York 2008, pp. 992f. and p. 1076f, M Phase in Animal Cells Depends on Centrosome Duplication in the Preceding Interphase.