Adolescent Idiopathic Scoliosis (AIS) is a prevalent developmental condition (affecting ~3% of the
population) of unknown origin, characterized by abnormal, three-dimensional spinal curvatures that occur
during phases of adolescent growth. Recently, numerous zebrafish models of AIS have emerged as powerful
tools for addressing etiology of the condition and characterizing the fundamental biological mechanisms that
facilitate spinal straightness. However, the varied genetic underpinnings of these models, the diversity of their
spinal curvatures, and complexity of the growing spine – a tissue that provides an interface for tissues of the
skeletal, muscular, and nervous systems – means that an ability to perform quantitative, phenotypic analysis
on micro-computed tomography (microCT) data is a critical barrier to our ability to describe the pathways that
mediate and maintain spinal straightness. The objectives of this proposal are to address this barrier to
progress by applying a new modality of quantitative, multiscale phenomics analysis to zebrafish models of AIS,
which will allow us to address fundamental questions about the developmental mechanisms that mediate and
maintain spinal straightness.
Recent work by my advisor has shown that zebrafish with mutations that paralyze motile cilia during
windows of juvenile growth develop three-dimensional spinal curvatures recapitulating AIS. Our Central
Hypothesis is that motile cilia of the spinal canal ependyma are critical signaling devices in the local
`perception' and mechanical correction of spinal straightness and curvature. We intend to challenge these
ideas through three Specific Aims: (1) Test the spatial requirement for motile cilia during spinal straightness.
(2) Identify which specific motile ciliated cell types are critical for a straight spine. (3) Test the requirement for
CSF-contacting neurons in a mechanical axis downstream of motile cilia. Research Design: We will use our
quantitative, multiscale phenomics platform to evaluate the impact of genetic manipulations involving either
global, partial, or cell-type specific inactivation of cilia motility on spinal straightness. This will inform our
understanding of how motile cilia relay information to their local tissue environments, contribute to our
fundamental understanding of how the spine “knows” to grow straight, and inform our future directions in the
research and treatment of AIS.