Time-lapse imaging was performed as previously described with some modifications [60 (link)]. Briefly, 2 μl of 1 mM levamisole solution was added into the center of the glass bottom of a microwell dish, then about 20 worms were transferred into the drop of levamisole solution. Next, a 4% agarose pad was gently added onto the animals. All time-lapse movies were taken using the spinning-disk confocal microscope, and Z stack images were processed by projection of maximum intensity except for
For Stimulated Emission Depletion Microscopy (STED) imaging, worms were immobilized using 1 mM levamisole solution and placed on 4% agarose pads. A Leica TCS SP8 STED fluorescence microscope equipped with 592/660/775 nm lasers, and a HC PL APO CS2 100×/1.40 oil objective was used for imaging. Z stack images were processed by the projection of maximum intensity.