During development, neural crest (NC) cells migrate extensively throughout the embryo, eventually giving rise to a number of cellular derivatives. While many factors that regulate NC migration have been identified, it remains unclear how NC cells penetrate through embryonic tissue in a directed manner. Here, Paul Kulesa and colleagues report that the transmembrane water channel Aquaporin 1 (AQP-1) plays a crucial role during NC migration in chick embryos. They first show that AQP-1 mRNA and protein are expressed in migrating cranial NC cells, notably at higher levels in leading NC cells. They further demonstrate that blocking AQP-1 function, using a chemical inhibitor or morpholino-mediated knockdown, slows NC migration. Conversely, AQP-1 overexpression increases NC cell speed and invasion. The authors further report that AQP-1 stabilizes NC cell filopodia, and is involved in promoting integrin turnover and MMP-mediated ECM degradation. Following this, they use computational modelling to show that enhanced collective cell migration can be achieved by a combination of increased cell speed, filopodia stabilization and ECM degradation. Finally, the researchers show that leading NC cells that express AQP-1 also express high levels of EphB guidance receptors, suggesting that AQP-1 is involved in the directed migration of NC cells. Overall, these findings suggest that AQP-1 allows lead NC cells to ‘bulldoze’ through the embryonic microenvironment in a directed manner.
