Fig. 1

The unique expression patterns of presecretory ameloblasts and secretory ameloblasts are identified through a comparison whole-transcript expression microarray analysis. a The anatomic structure of presecretory ameloblasts (PAB) and secretory ameloblasts (SAB) that were collected from 18–19-week-old human developing incisors using laser capture microscope (LCM). Low columnar epithelial cells (between the dashed white lines in the lower right panel) next to the dentin matrix (D) were microdissected as PAB. Elongated and polarized epithelial cells (between the dashed white lines in the top right panel) adjacent to the organic enamel matrix (E) were microdissected as SAB. b The number of significantly upregulated (top) and downregulated (bottom) genes expressed by PABs and SABs as compared to non-dental epithelial cells in each of the top eight most significant GO terms, grouped by various Gene Ontology (GO) processes. A number of genes that were significantly altered in both PAB and SAB were labeled as common (identified by slashes), and the number of genes that were unique to either PAB or SAB was labeled in purple or in green