English: Supplementary Video S1 shows the emergence of sarcomeric order in a simulated, one-dimensional acto-myosin bundle: Single, treadmilling actin filaments are shown in blue and red depending on the direction of their plus-end. At their plus end, actin filaments can become permanently crosslinked by a processive crosslinker that tracks actin plus ends while allowing for plus-end actin polymerization. Additionally, bipolar myosin filaments (magenta) dynamically attach to actin filaments in a polarity-specific manner, thus acting as a second set of active crosslinkers. Different vertical positions of the filaments are indicated solely for visualization purposes. Sarcomeric order in these simulated bundles can be quantified by the structure factor as defined in the main text (blue curves in lower panel). See also figure 3 in the main text.