Fig. 4. Time-space diagrams depicting coordinated desmosome-motility in PDc-13 cells (A) and MDc-2 cells (B) stably expressing fluorescent Dsc2a chimeras. The diagram on the left was derived from a time-lapse fluorescence recording of a cell contact region that was imaged for 3 hours at 2 minute intervals (Movie 3; jcs.biologists.org/supplemental ); the diagram at right was derived from a time-lapse fluorescence recording of a desmosomal array that was monitored for 10 hours at 5 minute intervals (Movie 4). Time is plotted along the y-axis in hours (h), whereas movement in the 2D space dimensions is plotted along the x- and z-axis in µm. The rough and sometimes interrupted surface of the desmosomal trajectories in MDc-2 cells is the result of the comparatively long recording intervals. Note the coordinated movement, constant arrangement, size and shape of the depicted desmosomes, whereas interdesmosomal distance varies considerably, albeit in a coordinated fashion (compare, for example, time points marked by arrows).