the microtubule-organizing center (mtoc) is a structure found in eukaryotic cells from which microtubules emerge. mtocs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division. the mtoc is a major site of microtubule nucleation and can be visualized in cells by immunohistochemical detection of Î³-tubulin. the morphological characteristics of mtocs vary between the different phylas and kingdoms. in animals, the two most important types of mtocs are the basal bodies associated with cilia and the centrosome associated with spindle formation. ==organization of mtoc in cells== microtubule-organizing centers function as the site where microtubule formation begins, as well as a location where free-ends of microtubules attract to. within the cells, microtubule-organizing centers can take on many different forms. an array of microtubules can arrange themselves in a pinwheel structure to form the basal bodies, which can lead to the formation of microtubule arrays in the cytoplasm or the 9+2 axoneme. other arrangements range from fungi spindle pole bodies to the eukaryotic chromosal kinetochores (flat, laminated plaques). mtocs can be freely dispersed throughout the cytoplasm or centrally localized as foci. the most notable mtocs are the centrosome at interphase and the mitotic spindle poles. centrioles can act as markers for mtocs in the cell. if they are freely distributed in the cytoplasm, centrioles can gather during differentiation to become mtocs. they can also be focused around a centrosome as a single mtoc, though centrosomes can work as an mtoc absent of centrioles. ==interphase mtoc== most animal cells have one mtoc during interphase, usually located near the nucleus, and generally associated closely with the golgi apparatus. the mtoc is made up of a pair of centrioles at its center, and is surrounded by p
Cytoskeleton Organelles