Anaphase (from Ancient Greek ἀνα- (ana-) 'back, backward', and φάσις (phásis) 'appearance') is the stage of mitosis after the process of metaphase, when replicated chromosomes are split and the newly-copied chromosomes (daughter chromatids) are moved to opposite poles of the cell. Chromosomes also reach their overall maximum condensation in late anaphase, to help chromosome segregation and the re-formation of the nucleus.[1]
Anaphase starts when the anaphase promoting complex marks an inhibitory chaperone called securin for destruction by ubiquitylating it. Securin is a protein which inhibits a protease known as separase. The destruction of securin unleashes separase which then breaks down cohesin, a protein responsible for holding sister chromatids together.[2]
At this point, three subclasses of microtubule unique to mitosis are involved in creating the forces necessary to separate the chromatids: kinetochore microtubules, interpolar microtubules, and astral microtubules.
The centromeres are split, and the sister chromatids are pulled toward the poles by kinetochore microtubules. They take on a V-shape or Y-shape as they are pulled to either pole.
While the chromosomes are drawn to each side of the cell, interpolar microtubules and astral microtubules generate forces that stretch the cell into an oval.[3]
Once anaphase is complete, the cell moves into telophase.[4]
- ^ "Chromosome condensation through mitosis". Science Daily. Retrieved 12 June 2007.
- ^ "The Cell Cycle". Kimball's Biology Pages. Archived from the original on 2012-11-19. Retrieved 9 December 2012.
- ^ Hickson GR, Echard A, O'Farrell PH (February 2006). "Rho-kinase controls cell shape changes during cytokinesis". Current Biology. 16 (4): 359–70. doi:10.1016/j.cub.2005.12.043. PMC 1525334. PMID 16488869.
- ^ Schafer KA (November 1998). "The cell cycle: a review". Veterinary Pathology. 35 (6): 461–78. doi:10.1177/030098589803500601. PMID 9823588. S2CID 43902779.