Dynamics of Cell Division: examining the basis of 'dynamic order' in the mitotic spindle 　　　　　The mitotic spindle is assembled during cell division to equally partition 　　　　　one copy of DNA into each daughter cells. It has been convenient to think 　　　　　of the mitotic spindle as being similar to a muscle that can both push and 　　　　　pull. However, the mitotic spindle is a self-organizing system that 　　　　　continuously consumes and dissipates energy to maintain itself and the 　　　　　microtubules, polymers of the cytoskeletal protein tubulin that provide the 　　　　　framework for force generating mechanisms in the spindle, are highly 　　　　　dynamic. The half-life of tubulin in the spindle has been estimated to be 　　　　　~90s and is likely to result from the superposition of dynamic instability 　　　　　of tubulin polymers and a process referred to as polewards flux, where the 　　　　　entire microtubule lattice translocates towards the spindle poles and this 　　　　　transport is tightly coupled to polymer assembly at one end and disassembly 　　　　　at the other. Real-time confocal and fluorescent speckle microscopy allow 　　　　　aspects of these cytoskeletal dynamics to be directly observed. By 　　　　　combining these microscopy-based approaches with molecule-specific 　　　　　perturbations, we are examining the contributions of individual motor 　　　　　proteins and MAPs (microtubule associated proteins) to the coordination of 　　　　　the complex transport and polymerization of tubulin to determine size, 　　　　　shape and rate of assembly of the cell division apparatus.