In cell biology, spindle apparatus refers to the subcellular structure that segregates chromosomes between daughter cells during cell division. It is also referred to as the mitotic spindle during mitosis or the meiotic spindle during meiosis.
While the spindle apparatus is composed of hundreds upon hundreds of proteins, the fundamental machinery are the spindle microtubules. Attachment of microtubules to chromosomes is mediated by kinetochores, which actively monitor spindle formation and prevent premature anaphase onset. Microtubule polymerization and depolymerization dynamics drive chromosome congression. Depolymerization of microtubules generates tension at kinetochores; bipolar attachment of sister kinetochores to microtubules emanating from opposite cell poles couples opposing tension forces, aligning chromosomes at the cell equator and poising them for segregation to daughter cells. Once every chromosome is bi-oriented, anaphase commences and cohesin, which couples sister chromatids, is severed, permitting the transit of the sister chromatids to opposite poles.
Read more about Spindle Apparatus: Spindle Structure, Organizing The Spindle Apparatus, Regulation of Spindle Assembly, Mitotic Spindle Assembly Checkpoint
Famous quotes containing the word apparatus:
“Man is the end of nature; nothing so easily organizes itself in every part of the universe as he; no moss, no lichen is so easily born; and he takes along with him and puts out from himself the whole apparatus of society and condition extempore, as an army encamps in a desert, and where all was just now blowing sand, creates a white city in an hour, a government, a market, a place for feasting, for conversation, and for love.”
—Ralph Waldo Emerson (1803–1882)