Principal Investigator Nikta Fakhri
The cortical actin cytoskeleton is a quasi 2D active material in which dynamics are dominated by rapid actin turnover and myosin-driven contractility. We map the dynamics of in vitro reconstituted actin cortices in emulsion droplets using IR fluorescent SWNTs. These reconstituted cortices exhibit different dynamic steady states with a change in connectivity. At critical connectivity, the 2D cortices form small clusters and locally break rotational symmetry. Beyond the critical connectivity, the system transitions to a system-wide contraction and global breaking of translational symmetry. We apply the new dynamic mapping technique to in vivo actin cortices in live starfish oocytes and drosophila embryos in various developmental stages.