Physical interpretation of microtubule self-organization in gravitational fields

This Letter discusses the role of key physical and chemical effects in the emergence of pattern formation in microtubule assemblies in vitro under the influence of gravity. The roles of chemical kinetics, diffusion, gravitational drift and electrostatic interactions affected by thermal fluctuations are discussed. The subtle interplay of these factors leads to the observed self-organization phenomena exhibiting the features of a typical polar liquid crystal phase.