Kinetochore-Microtubule Dynamics and Attachment Stability

Mitosis is the process by which a cell divides its genetic material equally into two daughter cells. Successful division requires that the two identical sister chromatids of a mitotic chromosome attach to the plus-ends of spindle microtubules (MTs) via their kinetochores, which are large protein structures built on centromeric DNA. Attachments between kinetochores and MTs must be persistent so that forces can be generated for chromosome movements, but at the same time they must be compliant, because attached MT plus-ends continuously polymerize and depolymerize to provide force for chromosome congression to the spindle equator. Both the attachment stability of kinetochore-MTs and the degree of dynamic instability exhibited by kinetochore-MTs must be precisely controlled to avoid errors in chromosome segregation. This chapter provides an overview of techniques used in cultured mammalian cells that measure stability and polymerization/depolymerization dynamics of kinetochore-MTs during mitosis.