19.6 Completion of Mitosis: Chromosome Segregation and Exit from Mitosis

Once all chromosomes have condensed and have correctly attached to the mitotic spindle, chromosome segregation commences. In this section, we discuss how cleavage of cohesins by a protease known as separase triggers anaphase chromosome movement and how this cleavage is regulated. We then see how the same machinery that initiates cohesin cleavage at the metaphase-anaphase transition, APC/C, also initiates mitotic CDK inactivation. Next we describe how phosphatases activated at the end of mitosis participate in mitotic CDK inactivation, bringing about the disassembly of mitotic structures and the resetting of the cell to the G1 state. We end this section with a discussion of cytokinesis, the process that produces two daughter cells.