A genetic model for the secretory stage of dental enamel formation.

A Hypothetical Molecular Model Showing How Ameloblasts Make Oriented Enamel Ribbons. [Display omitted] • Forty one genes are known to cause defects during the secretory stage of amelogenesis. • We propose a model for enamel mineral ribbon formation inclusive of these 41 genes. • Enamel ribbon formation is an evolutionary adaptation of the basement membrane. • Integrins α4/ß6; αVß6, COL17A1, Laminin 332, SLC13A5, ACP4, Enamelin, Ameloblastin. The revolution in genetics has rapidly increased our knowledge of human and mouse genes that are critical for the formation of dental enamel and helps us understand how enamel evolved. In this graphical review we focus on the roles of 41 genes that are essential for the secretory stage of amelogenesis when characteristic enamel mineral ribbons initiate on dentin and elongate to expand the enamel layer to the future surface of the tooth. Based upon ultrastructural analyses of genetically modified mice, we propose a molecular model explaining how a cell attachment apparatus including collagen 17, α6ß4 and αvß6 integrins, laminin 332, and secreted enamel proteins could attach to individual enamel mineral ribbons and mold their cross-sectional dimensions as they simultaneously elongate and orient them in the direction of the retrograde movement of the ameloblast membrane. [ABSTRACT FROM AUTHOR]