A developmental resource mapping tubulin isotype deployment during corneal morphogenesis

Microtubules are core cytoskeletal polymers that support epithelial organization, polarity, and tissue morphogenesis. They are composed of α- and β-tubulin heterodimers encoded by multigene families that generate closely related but distinct isotypes. Although several tubulin isotypes have been implicated in ocular development and disease, their spatial organization during corneal morphogenesis remains poorly defined. Here we establish a resource visualizing and quantifying tubulin isotype localization during corneal development using the chick embryo. Comparative amino acid sequence analysis demonstrates that chick and human α- and β-tubulin isotypes are highly conserved within structural and catalytic domains, with divergence concentrated in C-terminal regions normally associated with post-translational modification sites. Relating sequence features to tissue organization, we performed longitudinal immunohistochemical analysis of five tubulin isotypes across corneal development. These analyses reveal distinct and dynamic patterns of isotype enrichment along apicobasal axes, as well as stage-dependent redistribution during epithelial maturation and endothelial differentiation. TUBA5/TUBA4A displays particularly restricted localization, including enrichment in migratory corneal stromal progenitors and the developing corneal epithelium and endothelium. Together, these data provide a conserved spatial framework for tubulin isotype organization during corneal morphogenesis and establish the chick embryo as a tractable model for investigating isotype-specific microtubule organization during epithelial development.