Fig. 3.

The LMDP preferentially links cells of the same age. (A) X-Z image of the equatorial region of a tamoxifen-treated Cre-ER™;Z/EG lens. In this orientation, fiber cells are seen in transverse section. Near the surface, individual GFP-expressing cells are evident (arrows). At greater depths (>50 μm), GFP fluorescence is detected in a cluster of cells, suggesting that a GFP-expressing cell (^*) has become coupled to its lateral neighbors by the LMDP. (B) Lateral spread of large molecules is also observed following injection of fluorescent dextran. The upper left panel shows a lens in which an individual fiber cell (arrow) was injected with Alexa Fluor 488-Dextran and, at higher magnification (upper right panel), the appearance of the injected fiber cell 10 minutes (red) and 48 hours (green) after injection. The transects indicate the orientation of the optical sections shown in the lower panel. The X-Z section (lower panel) is oriented such that cells are seen in cross section. The distribution of Alexa Fluor 488-Dextran is shown 10 minutes (red) and 2 days (green) after injection. Ten minutes after injection the dextran is confined to the cytoplasm of the injected cell but, after 2 days in organ culture the dextran has spread laterally, into the cytoplasm of a layer of neighboring cells. Cap, capsule. Scale bars: 10 μm (A); 500 μm (B, upper left); 100 μm (B, upper right); 20 μm (B, lower panel).