Temporal and Spatial Dynamics of the Actin-Based Cytoskeleton
There has been a renaissance and revolution in the use of light microscopy in the biomedical sciences. The renaissance has been due to the importance of studying the temporal and spatial dynamics of ions, metabolites and macromolecules in living cells and tissues. The revolution has been due to the integration of developments in molecular biology, fluorescent probe chemistry, machine vision, and imaging technology. It is now possible to use the living cell as a microcuvette and to explore the chemical and molecular dynamics responsible for cellular functions.We have been investigating the formation, transport and contraction of stress fibers in Swiss 3T3 cells. Fluorescent analogs of actin, myosin, vinculin and profilin have been investigated in serum deprived cells before, during and after stimulation with thrombin. The activities of these components of the actin-based cytoskeleton have been quantified using time-lapse imaging, fluorescence redistribution after photobleaching, video-enhanced contrast and reflection interference contrast microscopy.