Figure 10.

HRP labeling and morphology of polarized MDCK cells. The ultrastructure of control (A) and JAS-treated (B and C) MDCK cells was examined after 15 min of HRP uptake from the basolateral side. All cells appeared as polarized monolayers with internalized HRP in a variety of compartments throughout endocytic pathways. Labeled structures were concentrated in the supranuclear or middle cell regions and were particularly prominent in JAS-treated cells, where they can be seen as clusters of tubular or multivesicular endocytic compartments containing HRP (arrows; B and C). In B, the apical microvillar surfaces of JAS-treated cells can be seen gathered up into prominent bunches (C), which were not present in control cells. Bar, 1 μm.