In this lecture, we will explore collective cell migration, a cellular behavior characterized by the coordinated movement of a group of cells, which is essential to morphogenesis and organogenesis throughout development. We will use the example of the zebrafish lateral line system to investigate how a 140-cell cluster known as latera line primordium successfully migrates over a distance of more than 1 mm, from near the ear to the tail of a larval fish. With no evidence of a molecular guidance gradient spanning the entire migratory path, researchers have suggested an intriguing hypothesis: that the primordium creates and maintains a self-generated guidance gradient as it moves. Today, we will discuss how researchers have demonstrated the existence of this elusive, self-generated gradient and unraveled the mechanism behind its formation.
Although unique to fish, the development of the lateral line system is a brilliant model from which a number of general principles of developmental biology can be learned. I highly encourage you to explore this model system further in the future.