Neural Crest Migration Orchestrated by Molecular and Mechanical Signals.

The neural crest is a highly migratory multipotent cell population traveling large distances in the vertebrate embryo. Neural crest cells migrate collectively in subpopulations, ranging in size from streams with hundreds of cells delaminating in the cephalic region to chains of single cells that delaminate in a dripping manner in the trunk. Here, we review the guidance mechanisms involved in neural crest migration and stream formation. We first describe established concepts of neural crest chemosensing and then highlight novel insights into biomechanical guidance. Finally, we propose how chemical and mechanical cues might interact and how neural crest cells can self-generate guidance gradients, facilitating robust guidance. Through this, we describe the mechanisms enabling neural crest cells to swarm collectively over large distances in a coordinated and directional manner within the complex in vivo environment of an embryo.