Fig. 6

Ameloblast layer’s barrier function is disrupted in Satb1^−/− mouse ameloblasts. a Claudin 1 (CLDN1) immunoreactive signal (in green) was detected primarily at the apical end of P1 wt presecretory ameloblasts (PAB) and underlying stratum intermedium (SI) b and P1 wt secretory ameloblasts (SAB) and SI. The cell nuclei were counterstained in blue. c CLDN1 immunoreactive signal in Satb1^−/− mouse PAB was primarily localized in SI beneath PAB. d Identical immunostaining pattern was found in SI under the Satb1^−/− SAB. OD, odontoblast; E, enamel. Scale bars, 20 μM. e A small amount of injected tracer molecule Sulfo-NHS-Biotin was detected in the enamel matrix (e) adjacent to wt SAB. f Significant more tracer molecule Sulfo-NHS-Biotin was found in the enamel matrix (e) adjacent to Satb1^−/− mouse SAB and at the surface of the enamel matrix layer. Scale bars: 50 μM