FIGURE 12.

Generation and active transcellular movements of ameloblast-associated bicarbonate and associated ion movements during enamel formation. Ion transporters, channels, and pumps are identified either by their name or gene symbol. Nucleus (Nu) and lysosome (Ly) are identified. The transport pathways are identified in a ruffle-ended ameloblast (RA). Many of these channels have also been shown in secretory ameloblasts (not shown) and smooth-ended ameloblasts (SA) but at significantly lower levels of expression. A dark gray double capsule represents a tight junctional complex at the apical region of RA, and a light gray double capsule represents a “leaky” junctional complex at the apical region of SA. Black broken arrow indicates the movements of small molecules through leaky junctional complexes.