Locomotion was assayed as previously described (Bettinger et al., 2012). Ten worms for each strain were tested in each assay, and we calculate the average of the speeds of the 10 worms in each iteration of the assay (n = 1). Comparisons were only made of animals tested simultaneously on the same plates. Briefly, Nematode Growth Media (NGM)-containing plates were dried for 2 hours with lids off at 37˚C, then copper rings were embedded in the surface of the plate to act as corrals. Ethanol was added to the plates to a final concentration of 0 mM or 400 mM, the plates were sealed, and the ethanol was allowed to equilibrate for 2 hours. Worms were placed in the corrals and two-minute movies were captured at 10 and 30 minutes of exposure using a Retiga 4000R camera (QImaging, Surrey, British Columbia) on an Olympus SZX-7 microscope. Movies were analyzed using ImagePro Plus (6.2) (MediaCybernetics, Rockville, MD) software. We derived two measures of ethanol response, Initial Sensitivity (depression of speed of locomotion at 10 minutes exposure compared to the same strain
