Immunohistochemical detection of acetylated H3K27 in the PN2 mouse lower incisor. A, Immunohistochemical detection of acetylated H3K27 during tooth development. B, Acetylated H3K27 was rarely detected at preodontoblasts. C, Weak detection of acetylated H3K27 was observed in the polarized odontoblasts. D, Acetylated H3K27 was highly expressed in the secretory odontoblasts. E, The expression of acetylated H3K27 was strongly localized in mature odontoblasts. Scale bar: A, 500 μm; B-E, 50 μm