A spatial and temporal atlas of tubulin isotype gene expression during vertebrate embryonic development

Epithelial-to-mesenchymal transitions (EMT) require extensive cytoskeletal remodeling to enable changes in cell polarity, adhesion, and migration. Although transcriptional programs controlling EMT are well characterized, how microtubule composition is developmentally regulated during cell state transitions remains poorly understood. Here, we establish a spatially resolved resource delineating the expression of α- and β-tubulin isotypes during neural crest (NC) EMT and tissue differentiation in the chick embryo. Integration of publicly available single-cell RNA sequencing datasets reveals diverse patterns of tubulin gene expression, ranging from broadly expressed isotypes (TUBA1A and TUBA1B) to more cell-type-restricted transcripts (TUBAL3 and TUBB4B). Several tubulin genes, including TUBB3, TUBA3E, and TUBG1, are enriched within NC and NC-associated cell types. Using fluorescence in situ hybridization chain reaction (HCR) to spatiotemporally characterize transcripts encoding selected tubulin isotypes, we validate these patterns and map their expression across developmental stages. These transcript patterns provide a map of tubulin gene expression, but additional studies are needed to determine how they relate to microtubule composition. We further show expression of the microtubule motor genes KIF11 and DYNC1LI1, revealing overlapping expression patterns between tubulin and motor-associated genes during EMT. Together, these data define a cell state-resolved atlas of tubulin gene expression during vertebrate EMT.