My project focuses on the roles of Kin I kinesins in mitotic spindle assembly and chromosomes movement. We have shown that one such kinesin, Kif2a, localizes to spindle poles in cultured cells and is required for spindle bipolarity through a mechanism distinct from that of Eg5. In the absence of Kif2a kinetochores pull centrosomes together, resulting in monopolar spindles. Spindle bipolarity can be restored in these cells by disrupting normal microtubule attachment to kinetochores (knockdown of Nuf2), or by stabilizing microtubules at plus ends (addition of nocodazole, or knockdown of MCAK).