The spindle checkpoint, also known as the metaphase-to-anaphase transition, the spindle assembly checkpoint (SAC), the metaphase checkpoint, or the mitotic checkpoint, is a cell cycle checkpoint during metaphase of mitosis or meiosis that prevents the separation of the duplicated chromosomes (anaphase) until each chromosome is properly attached to the spindle. To achieve proper segregation, the two kinetochores on the sister chromatids must be attached to opposite spindle poles (bipolar orientation).[1] Only this pattern of attachment will ensure that each daughter cell receives one copy of the chromosome. The defining biochemical feature of this checkpoint is the stimulation of the anaphase-promoting complex by M-phase cyclin-CDK complexes, which in turn causes the proteolytic destruction of cyclins and proteins that hold the sister chromatids together.[2]
- ^ Santaguida S, Musacchio A (September 2009). "The life and miracles of kinetochores". The EMBO Journal. 28 (17): 2511–31. doi:10.1038/emboj.2009.173. PMC 2722247. PMID 19629042.
- ^ Morgan, David Owen, 1958- (2007). The cell cycle : principles of control. London: New Science Press. ISBN 978-0-19-920610-0. OCLC 70173205.
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