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.
