Confocal snapshot of the active MT network in unconfined conditions. Short fluorescently labelled MTs, in the presence of crosslinkers, self-organize into extensile active bundles, propelled by kinesin motors (right). Scale bar, 100 m. This experiment was repeated twice. Top right: enlargement of the extensile bundles. A circle having a size comparable with the GUVs we produce ( R 0 25 m) is superimposed in red for reference. Scale bar, 50 m. Bottom right: schematic of the encapsulated experimental system. Inside the GUV (red circle), small MTs of opposite polarities assemble into bundles that are extended (see arrows) by kinesin motors (in yellow). This results in active extensile bundles confined inside the GUV.
