Premium
Ameloblastin‐rich enamel matrix favors short and randomly oriented apatite crystals
Author(s) -
Lu Xuanyu,
Ito Yoshihiro,
Kulkarni Ashok,
Gibson Carolyn,
Luan Xianghong,
Diekwisch Thomas G. H.
Publication year - 2011
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2011.00905.x
Subject(s) - apatite , enamel paint , matrix (chemical analysis) , dental enamel , materials science , dentistry , chemistry , mineralogy , composite material , medicine
Lu X, Ito Y, Kulkarni A, Gibson C, Luan X, Diekwisch TGH. Ameloblastin‐rich enamel matrix favors short and randomly oriented apatite crystals.
Eur J Oral Sci 2011; 119 (Suppl. 1): 254–260. © 2011 Eur J Oral Sci Molecular evolution studies suggest that amelogenin (AMELX), the principal component of the mammalian enamel matrix, emerged considerably later than ameloblastin (AMBN), and enamelin. Here, we created a transgenic mouse model to ask the question how a conceivable basal enamel lacking AMELX and enriched in the more basal AMBN might compare with recent mouse enamel. To answer this question we overexpressed AMBN using a keratin 14 (K14) promoter and removed AMELX from the genetic background by crossbreeding with amelx −/− mice. Enamel coverings of amelx −/− mice and of the squamate Iguana iguana were used for comparison. Scanning electron microscopic analysis documented that AMBN transgenic (TG) × amelx −/− mouse molars were covered by a 5 μm thin ‘enameloid’ layer resembling the thin enamel of the Iguana squamate. Transmission electron microscopy revealed that the enamel of developing AMBN TG × amelx −/− mouse molars contained short (approximately 70 nm) and randomly oriented crystals, while WT controls, AMBN overexpressors, and AMELX −/− mice all featured elongated and parallel oriented crystals measuring between 300 and 600 nm in average length. Together, these studies illustrate that AMBN promotes the growth of a crystalline enamel layer with short and randomly oriented crystals, but lacks the ability to facilitate the formation of long and parallel oriented apatite crystals.