Figure 2.

(a) Time-lapse sequence of a living wound-edge PtK cell expressing GFP–γ-tubulin; time, in minutes, is given in the lower corner of each panel. Bar, 5 μm. The direction of cell motility is toward the top of the page. Note the lagging of the centrosome behind the nucleus over time (small white dot). Other cells in this field of view were not expressing GFP–γ-tubulin and thus are not visible in the fluorescence image. (b) Histogram of rates of movement of the centrosome and nucleus for the cell shown in a; the end of the time interval used to determine the rates is shown on the x axis. (c–e) Plots of the distance the centrosome and nucleus moved from their initial positions over time. (b) Graph corresponds to the cell shown in a. In a and b, the nucleus moves a greater distance than the centrosome, leaving it behind. In c, the initial position of the centrosome is in front of the nucleus, and it remains there throughout the course of observation.