A spatial and temporal atlas of tubulin isotype expression during neural crest EMT

Abstract

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 - and {beta}-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, TUBA1B) to more cell-type-restricted transcripts (TUBAL3, TUBB4B). Several tubulin genes, including TUBB3, TUBA3E, and TUBG1, are enriched within NC and NC-associated cell types. Using fluorescent 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 further studies are needed to determine how they relate to microtubule composition. We further identify 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. SIGNIFICANCE STATEMENTThis study identifies tissue-and cell state-associated expression patterns of genes encoding tubulin isotypes and microtubule motors during NC EMT, providing a resource and spatiotemporal expression map for future work investigating how tubulin expression patterns may be linked to cytoskeletal remodeling and cell migration.