Review
Version 1
Preserved in Portico This version is not peer-reviewed
Anaphase A: Melting Microtubules Move Chromosomes toward Spindle Poles
Version 1
: Received: 4 February 2017 / Approved: 5 February 2017 / Online: 5 February 2017 (09:39:32 CET)
A peer-reviewed article of this Preprint also exists.
Asbury, C.L. Anaphase A: Disassembling Microtubules Move Chromosomes toward Spindle Poles. Biology 2017, 6, 15. Asbury, C.L. Anaphase A: Disassembling Microtubules Move Chromosomes toward Spindle Poles. Biology 2017, 6, 15.
Abstract
The separation of sister chromatids during anaphase is the culmination of mitosis and one of the most strikingly beautiful examples of cellular movement. It consists of two distinct processes: Anaphase A, the movement of chromosomes toward spindle poles via shortening of the connecting fibers, and anaphase B, separation of the two poles from one another via spindle elongation. I focus here on anaphase A chromosome-to-pole movement. The chapter begins by summarizing classical observations of chromosome movements, which support the current understanding of anaphase mechanisms. Live cell fluorescence microscopy studies showed that poleward chromosome movement is associated with disassembly, or ‘melting’ of the kinetochore-attached microtubule fibers that link chromosomes to poles. Microtubule-marking techniques established that kinetochore-fiber disassembly often occurs through a ‘pac-man’ mechanism, where tubulin subunits are lost from kinetochore-attached plus ends and the kinetochore appears to consume its microtubule track as it moves poleward. In addition, kinetochore-fiber disassembly in many cells occurs partly through ‘flux’, where the microtubules flow continuously toward the poles and tubulin subunits are lost from minus ends. Molecular mechanistic models for how load-bearing attachments are maintained to disassembling microtubule ends, and how the forces are generated to drive pac-man and flux-based movements, are discussed.
Keywords
anaphase A; kinetochore; chromosome-to-pole motion; pac-man; microtubule poleward flux; conformational wave; biased diffusion
Subject
Biology and Life Sciences, Anatomy and Physiology
Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Comments (0)
We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.
Leave a public commentSend a private comment to the author(s)
* All users must log in before leaving a comment
