Mitotic Apparatus

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mitotic apparatus

[mī¦täd·ik ‚ap·ə′rad·əs]
(cell and molecular biology)
A transitory organelle-like formation that is seen during mitosis and meiosis and consists of the asters, the spindle, and the traction fibers.

Mitotic Apparatus


a temporary structure in a dividing cell that enables the chromosomes to move to the poles of the cell, thus ensuring their even distribution between the daughter cells.

The mitotic apparatus consists of centrioles with the centre-spheres surrounding them, a cell division spindle with a system of microtubules, and an intermediate substance. Depending on the degree of development of astral rays around the centre-sphere, the mitotic apparatus is classified as astral (characteristic of most animal cells) or anastral (characteristic of plant cells). The mitotic apparatus is formed from macromolecules present in the interphase cell and from material synthesized before division. Its main components are ribonucleoproteins (about 90 percent proteins and 6 percent ribonucleic acid [RNA]). It also contains polysaccharides, lipids, and adenosine triphosphatase.

The proteins of the mitotic apparatus are contractile and are similar to muscle proteins in their amino acid composition. Usually, the mitotic apparatus starts to develop during prophase, is fully developed in metaphase, and begins to disintegrate in anaphase. Impairment of synthesis and injury to the mitotic apparatus result in mitotic pathology.

References in periodicals archive ?
In Crassostrea virginica, the centrosomes organized the microtubules from metaphase to late anaphase to establish the spindle apparatus.
Microtubules formed arrays in the mitotic phase, including a preprophase band (PPB), the spindle apparatus at metaphase and anaphase, and the phragmoplast at telophase, in the CK treatment (Fig.
25, 27) The discharge of spindles with a vertebra held at an intermediate position and during vertebral movement from that intermediate position decreases significantly when the intermediate position has been preceded by a vertebral position that maintains the spindle apparatus at longer length.
Based on their observations, the team derived a simple mathematical model describing the relationship between the size and shape of the spindle apparatus and the density and amount of microtubules.
It is one of the simple, reliable, least expensive and rapid screening system for both clastogenic (chromosome breakage, formation of a centric fragments) and an eugenic (chromosome lagging and effects on spindle) effects [4, 5], clastogenic and aneugenic agents affect the spindle apparatus, which can be differentiated on basis of the relative induced micronucleus sizes or with the presence of kinetochores [4, 6, 7].
The mitotic spindle apparatus has been for decades a primary target for the development of anti-mitotic agents such as the taxanes and vinca alkaloids which are broadly used in cancer therapies as single chemotherapeutic agents or in combination.
Within each cell, Xkid molecules are located inside the spindle apparatus, a structure required for cell division that's composed of a bundle of microtubules.