Multiple centrosomes: together they stand, divided they fall.

Cells with extra centrosomes rely entirely on centrosome clustering mechanisms to assemble a bipolar spindle and to divide in a bipolar fashion. To identify the pathways involved in suppression of multipolarity, Kwon, Godinho, and colleagues (pp. 2189-2203) have set up a genome-wide screen in Drosophila S2 cells. Surprisingly, they found that efficient clustering requires a large number of proteins associated with a variety of cellular functions.