Tubg1 Somatic Mutants Show Tubulinopathy-Associated Neurodevelopmental Phenotypes in a Zebrafish Model.

Abstract

Development of the multilayered cerebral cortex relies on precise orchestration of neurogenesis, neuronal migration, and differentiation, processes tightly regulated by microtubule dynamics. Mutations in tubulin superfamily genes have been associated with tubulinopathies, encompassing a spectrum of cortical malformations including microcephaly and lissencephaly. Here, we focus on γ-tubulin, a pivotal regulator of microtubule nucleation encoded by TUBG1. We investigate its role in brain development using a zebrafish model with somatic tubg1 mutation, recapitulating features of TUBG1-associated tubulinopathies in patients and mouse disease models. We demonstrate that γ-tubulin deficiency disrupts neurogenesis and brain development, mirroring microcephaly phenotypes. Furthermore, we uncover a novel potential regulatory link between γ-tubulin and canonical Wnt/β-catenin signaling, with γ-tubulin deficiency impairing Wnt activity. Our findings provide insights into the pathogenesis of cortical defects and suggest that γ-tubulin could be a potential target for further research in neurodevelopmental disorders, although challenges such as mode of action, specificity, and potential side effects must be addressed.