Spatially restricted activity of a Drosophila lipid phosphatase guides migrating germ cells

Temporal and spatial controls of cell migration are crucial during normal d evelopment and in disease. Our understanding, though, of the mechanisms tha t guide cells along a specific migratory path remains largely unclear. We h ave identified wunen 2 as a repellant for migrating primordial germ cells. We show that wunen 2 maps next to and acts redundantly with the previously characterized gene wunen, and that known wunen mutants affect both transcri pts. Both genes encode Drosophila homologs of mammalian phosphatidic acid p hosphatase. Our work demonstrates that the catalytic residues of Wunen 2 ar e necessary for its repellant effect and that it can affect germ cell survi val. We propose that spatially restricted phospholipid hydrolysis creates a gradient of signal necessary and specific for the migration and survival o f germ cells.