# Polymerization Force Driven Buckling of Microtubule Bundles Determines the Wavelength of Patterns Formed in Tubulin Solutions

## TL;DR

This study models how polymerization-driven buckling of microtubule bundles in solutions leads to patterned structures, estimating mechanical properties and revealing that bundles behave as solid rods during buckling.

## Contribution

It introduces a model linking microtubule polymerization forces to pattern formation and provides estimates for mechanical properties of microtubule bundles and networks.

## Key findings

- Polymerization generates compressional forces causing buckling.
- Bundles behave as solid rods during buckling.
- Estimated bending rigidity and elastic constants are consistent with observations.

## Abstract

We present a model for the spontaneous formation of a striated pattern in polymerizing microtubule solutions. It describes the buckling of a single microtubule (MT) bundle within an elastic network formed by other similarly aligned and buckling bundles and unaligned MTs. Phase contrast and polarization microscopy studies of the temporal evolution of the pattern imply that the polymerization of MTs within the bundles creates the driving compressional force. Using the measured rate of buckling, the established MT force-velocity curve and the pattern wavelength, we obtain reasonable estimates for the MT bundle bending rigidity and the elastic constant of the network. The analysis implies that the bundles buckle as solid rods.