To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S1. Barreling-type instability as a consequence of bulk active contractility. Sequence of shapes in Fig. 1E from σL/γ = 2.5 to σL/γ = 20 in intervals of 0.5. Active forces shape the metaphase spindle through a mechanical instability David Oriola, Frank Jülicher, and Jan Brugués PNAS. 2020. 117:16154-16159 DOI: 10.1073/pnas.2002446117 Download Original Video Browse All Videos »