Presenter: Colin Kuhns − Psychology
Faculty Mentor(s): Elizabeth Bearce
Session: (In-Person) Oral Panel—Bio-Zebrafish and DNA
The spine is the defining feature of vertebrate life. The morphology of the vertebral column emerges in animals during embryogenesis and continues to develop into adulthood. Motile cilia, beat back and forth on the surface of cells to generate microscopic fluid flows. The generated fluid flow is essential both for the initial generation of a linear body and for the maintenance of a linear spine. Urotensin-II-related peptides (URP), Urp1 and Urp2, are 10-amino acid cyclized peptides and are expressed in flow-sensory neurons in the central canal. Previous findings have hypothesized a model in which Urp1 and Urp2 promote the axial straightening downstream of motile cilia function through inducing contraction of dorsal muscles. However, it has remained unknown whether Urp1 and/or Urp2 also function beyond embryogenesis in the maintenance of spine morphology during growth. Here we show that Urp1 and Urp2 are in fact dispensable for axial straightening during embryonic and early larval phases, contradicting the current model. Instead, we found that Urp1/Urp2 are essential for maintaining spinal linearity during later growth phases, with clear spinal dysmorphology in mutants during juvenile growth. Curves induced upon loss of Urp1/Urp2 model aspects of kyphosis and are distinct from curves exhibited by cilia motility mutants. Overall, this work links Urotensin peptide signaling to spine morphology and provides a new animal model for the common human spine dysmorphology of kyphosis.