The ethanol behavioral responses of dlpf03537 and dallyMB950 flies differed significantly from controls, and they were qualitatively similar to each other. Ethanol-induced locomotor activity in homozygous mutant flies was the most similar response; both mutant strains, as homozygotes, showed significantly reduced ethanol hyperactivity (Figure 2, B and F, left panels). Interestingly, heterozygous mutants showed the opposite result of increased ethanol hyperactivity, but only dlpf03537 heterozygotes showed a significant increase (Figure 2, B and F, right panels). Given that the expression and complementation experiments indicate that transcript levels decrease with the number of mutant alleles, the simple model that ethanol hyperactivity decreases with decreasing transcript is not supported; a more complex relationship between dally and dlp gene expression and ethanol hyperactivity must exist. dallyMB950 and dlpf03537 mutants were also similar in their ethanol sedation sensitivity. Because of the weak viability of dlpf03537 homozygotes, only heterozygotes were generated in sufficient numbers for the sedation assays. The dlpf03537 heterozygotes displayed increased sedation sensitivity (Figure 2D). dallyMB950 heterozygotes and homozygotes were both more sensitive to the sedating effect of ethanol, with the homozygotes exhibiting
