Recent Advances on Structure and Function of Mitotic Cell Spindles (microtubule, centriol, chromosome interrelations)

Authors: Alp CAN

Abstract: Mitotic spindle is an intracellular structure formed by unique remodeling of microtubules. It is appeared both in mitosis and meiosis, former is a common type of cell division that aims to increase the cell number in all eukaryotes and protozoa, where the letter aims to reduce the chromosome number in gametic cells of eukaryotes. Its function remains unchanged eventhough its structure shows interspecious variations (astral, anastral and spindle polar bodies) in animals and plants. Origin of microtubules that form mitotic spindles is a gamma-tubulin containing dense substance called pericentriolar material. It was demonstrated that, pericentriolar material plays a key role in formation of spindle in which presence of centrioles could almost be neglected. Spindle microtubules attach to chromatids and pullthem toward spindle poles during mitosis. This is achieved by their rapid assembly and disassembly features. Spindles contain a variety of components in addition to microtubules. Among the motor proteins like dynein and kinesin that regulates assembly/disassembly rate and drive the attachment to chromatids, microtubule associated proteins (MAP); vesicles and tubules that are proposed to play role in mediating the calcium ion concentration.

Keywords: Chromosome, Mitosis, Mitotic Spindle, Microtubules, Centriol.