Subcellular spatial precision of ER mechanostimulation. The cell was subjected to two rounds of light stimulation restricted to different subcellular areas indicated by blue boxes (1st and 2nd). Each stimulation induced ER stretching and rearrangement in the targeted area, with the morphology of unilluminated ER remaining relaxed and unstretched. One 100-ms pulse blue light (240 mW/cm2) was delivered to (A) the whole cell or (C) subcellular regions marked by blue rectangles. Scale bars, 10 m. See alsoFigure S1andVideos S3andS4.
