To formally investigate mini-w in ethanol sensitivity in eRING assays, we used nervous system Gal4 (elav-Gal4) (Olofsson and Page, 2005) to drive expression of a UAS-white-RNAi transgene (v30034) to knockdown mini-w (Figure S2I, K and M). In all experiments, the elav-Gal4 and UAS-white-RNAi transposons contained the mini-w marker (Figure S2). White-eyed flies with the w1118 null allele or with RNAi-mediated knockdown of mini-w (elav-Gal4,v30034) were significantly more sensitive to ethanol in eRING assays than red-eyed flies expressing mini-w from the elav-Gal4 (elav-Gal4/+) or v30034 (v30034/+) transgenes (Figure 1B). Additionally, w1118 null flies were much more sensitive to ethanol in eRING studies than flies with a wild-type allele of w (w+) in the same genetic background (Figure 1C). Both mini-w and endogenous w, therefore, have substantial effects on ethanol sensitivity in the eRING assay. Given the widespread use of flies with altered expression of w (for example, >75% of the ~46,000 stocks in the Drosophila Bloomington Stock Center contain an allele of w or mini-w at the time of manuscript preparation), our findings represent a significant limitation to the utility of
