Fig. 3.

NCKX4 immunolocalization in the developing mandibular incisor of a 3-week-old mouse. A No NCKX4 staining was visible in secretory-stage ameloblasts. B Staining is evident at the apical pole of early maturation-stage ameloblasts. Weak staining is also visible in the papillary layer (PL). C Mid-late maturation-stage ameloblasts and PL stain for NCKX4 with stronger signals detected at the apical pole of ameloblasts identified by double asterisks (**). D Higher magnification (× 100) image of mid-late maturation-stage ameloblasts showing strong reactivity at apical pole as marked by double asterisks, and extending to the lateral membranes (arrowheads). E Negative control: mid-late maturation-stage ameloblasts were incubated with no primary NCKX4 antibody but all other steps were performed. No positive staining was visible in this tissue section. F, G Odontoblasts showed positive staining when incubated with NCKX4 (F), whereas the negative control (no primary antibody) showed no staining (G). H, I Skeletal muscle (tissue control): H shows positive staining, but the negative control (no primary antibody) did not stain (I ). En = enamel; Mat Am = maturation ameloblasts; Neg. = no primary antibody; Od = odontoblasts; PL = papillary layer; Sec Am = secretory ameloblasts; SM = skeletal muscle; Sr = stellate reticulum. A–C, E, H, I Scale bars: 50 μm. D Scale bar: 10 μm. F, G Scale bars: 30 μm.