Chromosome Capture and the Mitotic Spindle

Abstract

This thesis investigates the effects of a RanGTP gradient and branching nucleation on microtubule dynamics, specifically focusing on the first passage time for microtubule-kinetochore contact. RanGTP has been investigated as a possible cause of anisotropy in the formation of the mitotic spindle. The most probable mechanism for such an effect would be RanGTP affecting the activity levels of other protein species near the microtubule, lending the microtubule increased stability in regions with high concentration of RanGTP. Microtubule branching, though well acknowledged in plants, has only recently been demonstrated in animal cells. As branching might allow microtubules to explore more space, we conjectured that it decreases the mean first passage time for chromosome capture. Here we present microscopic Markov models and macroscopic simulations that can be used to investigate these phenomena as well as a review of recent experimental results.