We tested mutant flies for sensitivity to ethanol sedation using a modified loss-of-righting (LOR) assay and found that the f01491 and MB06458 insertions conferred increased resistance to ethanol sedation (Figure 2C, D). The time for 50% of the flies to become sedated (ST50) was calculated from the sedation curves by linear interpolation [5]. Flies carrying the f01491 insertion sedated significantly later than control flies, with an ST50 of 11.5 min compared to 8.4 min (Figure 2C). Flies with the MB06458 insertion also exhibited significantly delayed sedation with an ST50 of 13.5 min compared to 10.5 min for the control line (Figure 2D). The effect on ethanol sedation in these lines was not due to a difference in pharmacokinetics, as controls and mutant flies absorbed the same amount of ethanol (Figure S1). We next examined whether re-expressing dAlk in neurons of f01491 mutant flies would rescue the ethanol sedation phenotype of the mutant. The f01491 mutant flies were crossed to flies carrying elav-GAL4c155 to drive neuronal expression of dAlk from the P-element insertion in the f01491 mutant, which contains UAS sites
