Enamelin Is Critical for Ameloblast Integrity and Enamel Ultrastructure Formation
Figure 5
Immunohistochemical staining of PN7 and PN14 molars using amelogenin rm179 polyclonal and enamelin mENAM223–236 antipeptide antibodies.
(A–V) Weak amelogenin positive staining can be detected in PN7 and PN14 molars of wild type (A–B and M–N, arrowhead), Enam+/− (E–F and Q–R, arrowhead), and Enam−/− (I–J and U–V, arrowhead) mice. (C–D versus G–H) A similar distribution pattern but with slightly different intensities of enamelin staining is apparent comparing wild type to Enam+/− samples. The enamelin positive staining is evenly distributed across the entire thickness of enamel layer in wild type and Enam+/− samples. (K–L) However, no positive staining can be detected in Enam−/− molars. (I, K, U, W) Abnormal accumulations of organic matrix are evident on the mesial and distal cusp slopes in Enam−/− samples. (M–V) The trend continued into PN14, with amelogenin signals becoming more intense in all three genotypes. (O–P) Enamelin expression is evident in the wild type, trace amounts of expression in the Enam+/− molars (S–T) but complete absence in Enam−/− molars (W–X).