In higher eukaryotes, the position of cytokinesis is determined by the position of the mitotic spindle (Rappaport, 1990). Generally, the spindle sits in the middle of the cell and cytokinesis produces two equivalent cells. However, many developmental processes require specific positioning of the cleavage plane and, hence, the mitotic spindle. For example, control of spindle position can be used to asymmetrically distribute cell fate determinants between the two daughter cells, to form polar bodies during oogenesis, and for tissue morphogenesis (Stearns, 1997). Positioning of the spindle appears to be mediated through the attachment of astral microtubules to filamentous actin at the cell cortex (Lutz et al., 1988; Hyman, 1989; Waddle et al., 1994).
In budding yeast, the site of cell division is specified at the start of the cell cycle by the location of the bud site. The mitotic spindle...
