Mutational and antisense screens in Drosophila and zebrafish, and transcriptional profiling and time-lapse analysis in the mouse, have contributed greatly to our understanding of PGC development. In all three systems, the behavior of PGCs is controlled by growth factors which signal through G-protein coupled receptors and/or tyrosine kinase receptors. Additionally, regulated cell-cell and cell-substrate adhesion is important for PGC motility. Finally, localized growth factors may control PGC survival and consequently PGC position. Chemotaxis, regulated adhesion and cell survival are important for multiple migration processes which occur during development and disease. PGC migration shares these features.