Final answer:
In a migrating fibroblast, the highest traction forces are present at the trailing edge where retraction fibers attach to the substratum, and movement direction is influenced by substrate stiffness and the dynamics of cell-substrate adhesion.
Step-by-step explanation:
In a migrating fibroblast, the traction forces that facilitate cell movement are at their highest at the cell's trailing edge, particularly at the sites where retraction fibers remain attached to the substratum. These forces are generated by actin-myosin interactions, which, upon sliding, cause the retraction of the rear of the cell. During this migration, adhesion sites become important as they develop in the interface between the lamellipodium and the substrate.
Oriented movement, such as towards clamped surfaces that present maximal stiffness, is influenced by the rigidity of the substrate, a phenomenon termed durotaxis. Moreover, the physical environment plays an essential role in cell migration, where matrix stiffness, tensional remodeling, and detection of substrate strains by adjacent cells can influence movement direction and efficiency. Traction forces are highest at the trailing edge of a migrating fibroblast, influenced by the concept of durotaxis and the dynamics of adhesion and retraction at the cell-substrate interface.