Divergent Spatiotemporal Expression Patterns of Histone Deacetylases During Mouse Embryonic Tongue, Palate, and Mandible Development.

Epigenetic regulation is indispensable for embryonic development, yet the specific roles of histone deacetylases (HDACs)-a core family of epigenetic regulatory enzymes-in orchestrating craniofacial morphogenesis remain incompletely elucidated. C57BL/6 mouse embryos spanning embryonic Day 12.5 (E12.5) to E16.5 were analyzed. Histological staining (hematoxylin-eosin and Masson staining) was used to characterize morphological development of the tongue, palate, and mandible. Immunohistochemistry (IHC) was performed to map the spatiotemporal expression patterns of HDAC1-11. HDAC1 expression was scarcely detectable throughout the entire E12.5-E16.5 period. In contrast, HDAC2 showed robust expression in the mandible and tongue from E13.5 to E15.5. Notably, HDAC2 also exhibited strong positive staining in palatal epithelial cells at E14.5. By E16.5, HDAC1-10 expression became barely detectable in tongue, palate, and mandible, whereas HDAC11 retained intense expression specifically in the mandible at this late maturation stage. HDAC family members exhibit divergent spatiotemporal expression profiles during craniofacial development, with distinct subtype-specific patterns that align with key stages of tongue, palate and mandible morphogenesis. These findings establish a comprehensive spatiotemporal expression atlas of HDAC1-11 in developing craniofacial organs, providing essential foundational data to guide future investigations into the epigenetic regulation of craniofacial development.