Movie 2.

HUVECs were plated on ibidi dishes until 50% confluence and incubated with 1µM SiR-actin for 1h. Cells were then induced with Activin A and placed in a 37°C, 5% CO2 chamber. Video Microscopy followed according to Materials and Methods. Images were converted to a video using Image J and exported in avi format (video1&2: 3fps). The video is accelerated for visualization (fast-forward × 90 times).