Cytokinesis: an emerging unified theory for eukaryotes?

In animal and fungal cells, cytokinesis involves an actomyosin ring that fo rms and contracts at the division plane. Important new details have emerged concerning the composition, assembly, and dynamics of these contractile ri ngs. In addition, recent advances suggest that targeted membrane addition i s a central feature of cytokinesis in animal cells - as it is in fungi and plants - and the coordination of actomyosin ring function with targeted exo cytosis at the cleavage plane is being explored. Important new information has also emerged about the spatial and temporal regulation of cytokinesis, especially in relation to the function of the spindle midzone in animal cel ls and the control of cytokinesis by GTPase systems.