Figure 2. Endocytic events are randomly distributed within ER-free PM areas.

In tangential confocal sections of individual W303 cells expressing Ede1-GFP and ss-dsRed-HDEL (A), the minimal distance of endocytic sites from the cortical ER boundary was measured. The histogram of the measured distances (full bars in B; 906 sites in 200 cells were analyzed) was compared to the distribution of the distances of model foci randomly positioned in the plasma membrane (empty bars in B; 320 foci in 100 cells; see Methods for details). In order to maximize the accuracy of the distance measurements, for all the measurements we chose only the foci located to easily discernible ER holes positioned in central parts of the tangential confocal sections, so that the entire borders of the holes could be traced. Bar: 1 µm.