Cilia-driven cerebrospinal fluid flow directs expression of urotensin neuropeptides to straighten the vertebrate body axis.

Straightening of the body axis is a major morphogenetic event that produces the typical head-to-tail shape of the vertebrate embryo. Defects in axial straightening can lead to debilitating disorders such as idiopathic scoliosis, characterized by three-dimensional curvatures of the spine. Although abnormal cerebrospinal fluid (CSF) flow has been implicated in the development of idiopathic scoliosis, the molecular mechanisms operating downstream of CSF flow remain obscure.