Figure 3

The distribution and intermediate fragment patterns of ENAM in 6-d-old ENAM^Rgsc514 mice. (a) and (b) Immunohistochemcal staining of ENAM in the first lower molars of the 6-d-old WT mice showed that the N-terminal fragments of ENAM were distributed in the outer half of enamel matrix and nearly undetectable in the ameloblasts. (c) and (d) In ENAM^Rgsc514 heterozygotes (Het), the N-terminal fragments of ENAM were localized at the mineralization front (arrowheads) of enamel matrix (EN) and strongly stained in the cell body of the ameloblasts (AM). (e) and (f) In the ENAM^Rgsc514 homozygotes (Homo), the N-terminal fragments of ENAM were strongly stained in the scattered amorphous ‘enamel matrix’ (asterisk). (g) and (h) The C-terminal fragments of ENAM are distributed in the inner half of enamel matrix in the WT mice. (i) and (j) The C-terminal fragments of ENAM were distributed in the inner ½ of enamel matrix, which is pattern similar to that in the WT mice. (k) and (l) The C-terminal fragments of ENAM were undetectable in the ‘enamel matrix’ of the ENAM^Rgsc514 homozygotes. (m) Western immunoblotting showed that the ENAM^Rgsc514 mice appeared to have less ENAM than the WT mice, while their intermediate fragment patterns are similar. Scale bars: 200 μm in a, c, e, g, i, and K. 50 μm in b, d, f, h, j, and l.