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Phenotype Image Detail
Image
Caption Transmission and scanning electron microscopic images of enamel architecture changes by redesign of amelogenin in mouse incisor teeth. Images in panels A reflect the enamel organization from an Amelxtm1Msnd/Amelxtm1Msnd (deltaA/deltaA) mouse, panels B reflect the enamel from an age matched wild type mouse (Wt/Wt), and panels C reflect the enamel from a Amelxtm2Msnd/Amelxtm2Msnd (deltaB/deltaB) mouse. The images shown in panels 1 are transmission electron microscopy projections from an area adjacent to the secretory end of the ameloblasts and reveal newly synthesized enamel matrix proteins and crystallites. The loss of nanospheres and increased numbers of shortened crystallites is identified in Amelxtm1Msnd/Amelxtm1Msnd, and a collapse of nanospheres with disruption of crystallites is seen in Amelxtm2Msnd/Amelxtm2Msnd compared with wild type enamel. The images shown in panels 2 and 3 are scanning electron micrograph (SEM) projections at two magnifications of cross-sections of incisors obtained by fracture at similar areas of enamel maturation. The enamel is thinned, the rod-interrod demarcations are disrupted and the weaving among the enamel rods is absent in both mutants compared with wild type. The dotted line identifies the dentine enamel junction. The images shown in panels 4 and 5 are SEM projections at two magnifications of the newly formed enamel surface after the removal of the ameloblast cells. Disruption to the shape and size of the secretory end piece of ameloblasts, known as Tome's processes, are observed. For the enamel made from Amelxtm1Msnd/Amelxtm1Msnd amelogenin, the secretory end pieces are squat and enlarged. In the enamel made from Amelxtm2Msnd/Amelxtm2Msnd amelogenin, the secretory end pieces are more numerous but smaller. These changes to Tomes' processes are reflected in the rod organization shown in SEM images from fractured enamel in panels 2 and 3.
Copyright This image is from Zhu D, J Biol Chem 2006 Jul 28;281(30):21173-82 and is displayed with the permission of the American Society for Biochemistry and Molecular Biology who owns the Copyright. Full text from JBC. J:116448
Associated
Alleles
Symbol Name
Amelxtm1Msnd amelogenin, X-linked; targeted mutation 1, Malcolm L Snead
Amelxtm2Msnd amelogenin, X-linked; targeted mutation 2, Malcolm L Snead
Associated
Genotypes
Allelic Composition Genetic Background
Amelxtm1Msnd/Amelxtm1Msnd involves: 129X1/SvJ
Amelxtm2Msnd/Amelxtm2Msnd involves: 129X1/SvJ

Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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last database update
11/19/2024
MGI 6.24
The Jackson Laboratory