Gene analysis of ameloblasts in Sox21KO. Mus musculus

Tooth and hair development starts from ectodermal invaginations. However, the determination of organ-specific cell fates is poorly understood. The transcription factor Sox21 is expressed in the epithelium of developing teeth. We discovered that disruption of Sox21 caused severe enamel hypoplasia and ectopic hair formation in the gingiva in Sox21 knockout incisors. We dissected tooth germ from P1 Sox21 KO and control incisors for microarray. In particular, several markers of ameloblast maturity, i.e. amelotin (Amtn), laminin α3 (Lama3), and kallikrein-related peptidase 4 (Klk4), were included among the downregulated molecules in Sox21 KO tooth germ, whereas the expression of Mmp20 and Amel was not changed. On the other hand, numerous keratin-related genes were upregulated in the Sox21 KO tooth germ and WT skin. As in the microarray results, the expression of dental epithelial stem cell marker Sox2, as well as keratin family and hair-related genes such as Lgr5, were increased in Sox21 KO dental epithelium. Taken together, these results reflected the perturbed differentiation of ameloblasts and a cell fate change in the Sox21 KO incisors. Overall design: Microarray Analysis of Ameloblasts in the Sox21 KO Mouse Incisor ameloblasts and whole tooth germs were isolated from P0 wild-type (WT) and Sox21 KO mice. Labeled RNA samples were hybridized onto SurePrint G3 Mouse GE 8×60K microarrays.