Limitation of substratum size alters cytoskeletal organization and behaviour of Swiss 3T3 fibroblasts

Abstract Cell spreading and adhesion formation in Swiss 3T3 cells was studied on circular adhesive islands of size 400–5000 (μm 2 made by evaporating palladium through a mask onto an underlying non-adhesive surface. Cell spreading was limited since focal contacts were restricted to the palladium. On islands 2 , focal contacts and actin bundles were arranged at the cell periphery. On islands 2 , the size and number of focal contacts were reduced. Focal contacts may be important regulators of proliferation, but they do not seem to form a deterministic link between substratum contact and proliferative stimulus.