Tracing the Current: cacna1c Mutation and its Effect on Neural Crest Cell Dynamics and Early Bioelectric Pattern in Danio rerio

Timothy Syndrome (TS), an autosomal dominant disorder caused by a heterozygous de novo mutation in cacna1c, disrupts voltage-gated calcium (Ca²⁺) signaling through dysregulation of the Cav1.2 L-type Ca²⁺ channel. This dysregulation perturbs Ca²⁺-dependent bioelectric patterning, resulting in developmental anomalies, such as craniofacial malformations, including reductions of the mandible. The craniofacial structures are derived from cranial neural crest cells (CNCCs), a subset of the migratory, multipotent progenitor neural crest cell population, yet the mechanistic link between cacna1c-mediated Ca²⁺ disruption and CNCC behavior remains unresolved. Leveraging the zebrafish (Danio rerio) model, which offers well-defined CNCC-derived craniofacial structures and robust cellular analysis and imaging tools, we investigated cacna1c expression and function during embryogenesis. Hybridization chain reaction (HCR) revealed cacna1c expression in CNCC populations during segmentation. The knockdown of cacna1c using two splice-blocking morpholinos induced physiological defects, including somitic truncation and cardiac dysfunction. Genetic encoded voltage indicator (GEVI) Marina transgenic embryos demonstrated regional depolarization that is time sensitive, potentially demonstrating a physiological link to CNCC dysregulation. Immunofluorescence (IF) further identified perturbations in CNCC dynamics that primarily affected proliferation rates and migratory patterns. Together, these preliminary results showcase that Ca²⁺-dependent bioelectric signaling is disrupted in cacna1c knockdown, which alters CNCC dynamics. This work expands our understanding of how ion channel dysfunction, as seen in Timothy Syndrome, could influence NCC-driven processes and their broader developmental outcomes on morphogenesis.