The p120 null ameloblasts detach from the incisor dentin surface, the stratum intermedium, and from each other.

Abstract

<p>Secretory ameloblasts (Am) are identified by positive immunostaining for amelogenin. Panels A–D represent sequential sections of an incisor from a cKO mouse. Pre-secretory ameloblasts do not express amelogenin (A) whereas secretory stage ameloblasts do express amelogenin (B–D). Note the vacuoles above the ameloblasts in the stratum intermedium (SI) that grow progressively larger as development progresses. The right side of panel D shows ameloblasts that have completely lost contact with the stratum intermedium. However, the ameloblasts also lose contact with the dentin surface and with each other (E, F). The ameloblasts in panels E and F are disorganized and appear to have lost most but not all cell adhesion properties so they appear stretched between the stratum intermedium and dentin. Od, odontoblast; SR, stellate reticulum.</p