From Self-Organized Fluid Machines to Living Liquid Crystals

The self-organization of amoeboid cells is discussed. The ordered state of amoeboid cells is produced out of a uniform state by an instability of the intracellular signal chain. The temporal pattern makes the the machine cycle while the spatial pattern produces the spatial spread machine: (i) an inactivated cellular state is predicted for low pumping; (ii) an isotropic mode for higher pumping (cell adhesion but no migration); (iii) a polar mode for even higher pumping (adhesion and directed migration); (iv) a bipolar activated cellular mode for even higher pumping (cell elongation and orientation); The machine characteristics of the different activated modes are discussed. An automatic controller (= controller with feedback) is responsible for the angle of migration and for angle of orientation. Migrating and interacting cells can form condensed states: A polar nematic liquid crystal is found for cells in the polar mode and an apolar nematic liquid crystal for cells in the bipolar mode.