Strong, inward traction forces appear at both the frontal and rear ends of migrating fibroblasts. They have the opposite effects of propelling versus resisting cell migration. To test if active contractions are similarly involved in both regions, migrating 3T3 fibroblasts were treated locally with an RGD peptide to induce detachment. The response of traction forces was monitored simultaneously. Local traction forces resulting from the transmission of contractions elsewhere should be sensitive to detachment at the origin. |