Observation of fluctuation of actin filaments in living cell

Abstract

Actin filaments play a major role for maintain the cell morphology and sensing mechanical stresses in many types of cell. It is well known that cytoskeletal structure and proteins in and on cells are fluctuating with the thermal effect. Here, we have observed very small fluctuation of actin filaments in living cell. Actin filaments in NIH3T3 were visualized with Lifeact-GFP fusion protein. The fluorescent images were taken with the forcal microscopy 10 images every second. From the sequential images, we analyzed the width and frequency of actin fluctuation. The frequency of actin fluctuation was about 2.3 Hz and the width was 0.3 μm. It is possible that these values are affected with mechanical conditions, such as flow and the change of temperature. We continue to analyze the actin fluctuation under several types of mechanical conditions.