Centrosome

The centrosome (also centrosome or centrioles ) is an organelle that organizes in most animal cells, the mitotic spindle. Thus, it is a MTOC ( eng. ' microtubule organizing center' ). It was discovered in 1888 by Édouard van Beneden and named by Theodor Boveri in 1888 and described as ' special organ of cell division '.

The centrosome is a conspicuous region in the cytosol, which is found mostly in the center and in the vicinity of the nucleus. It consists of a pair of orthogonal, cylindrical centrioles, which are in a protein matrix, the trio peric lar matrix embedded. The duplication of the centrosome ( centrosome cycle ) takes place in coordination with the duplication of chromosomes (chromosome cycle) during DNA synthesis phase ( S phase). The molecular mechanism of Zentrosomenduplikation is not yet known, it is absolutely necessary at each of the two Mutterzentriolen grow a Tochterzentriol, which eventually leads to two complete centrosomes. (Semi Conservative Replication).

Before the start of mitosis, the two centrosomes separate and migrate to opposite poles of the cell. Each centrosome is the starting point of a great number of microtubules that make up the mitotic spindle apparatus. After the nuclear and cell division then each daughter cell each one of the two centrosomes.

Plant cells generally do not contain centrosomes. For higher plants ( angiosperms ) they are absolutely lacking.