Fig. 1. Cell body displacement stimulates growth of peripheral adhesions in B16 melanoma cells and the polymerisation of microtubules towards the cell edge. (A) Video frames show a motile cell, expressing GFP-VASP, whose cell body was displaced by a microneedle in the direction indicated in the phase contrast image. Panel 0'00'' in this and subsequent figures corresponds to the video frame before tension application. Boxed insets in the fluorescence images show enlargement of peripheral adhesion sites in the region diametrically opposite the cell body. The continued protrusion of the cell edge is indicated by the persistence of the line of GFP-VASP at the tip of the lamellipodium. An example of one from five cells is shown. Times are in minutes and seconds. Bar, 10 µm. (B) The conditions used were the same as in A for a B16 melanoma cell expressing GFP-tubulin. Arrows in the phase contrast and fluorescent images of the video sequence indicate the direction of stress application. Insets show invasion of microtubules into lamella region in the line of applied stress. An example of one from seven cells is shown. (C) The conditions used were the same as in A for a B16 melanoma cell expressing GFP-CLIP-170. Arrows indicate the direction of stress application. Note the increase in number of polymerising microtubules in peripheral lamella (ellipse), which are marked by GFP-CLIP-170 at their tips. An example from one from 15 cells is shown.