Many types of cells position their spindles to control the position and orientation of the division plane. This strategy is used during embryonic development to partition asymmetrically localized cell differentiation factors into one or the other of the daughter cells. Spindle position and orientation also determines the architecture of many tissues. Generally, spindle movements are accomplished through interactions between the cortex of the cell and astral microtubules emanating from the ends of the spindle. However, the mechanisms for force production and the signals that coordinate the completion of mitosis with cytokinesis are not well understood.