Figure 2. The rutabaga adenylyl cyclase is acutely required for an ethanol preference.

(a) rut²⁰⁸⁰ mutants and control CS flies were examined in the CAFE assay. The rut²⁰⁸⁰ mutants display a significantly reduced preference for 10% and 15% ethanol compared to wild-type CS. (b) Mutants in the dunce phosphodiesterase were also examined in the CAFE assay. The dnc¹ loss-of-function mutants exhibited a normal preference for 5%, 10% and 15% ethanol. (c) In the PER assay, rut²⁰⁸⁰ did not show a significant difference with CS, to liquid food without or with ethanol, except for 15% ethanol, indicating that the rut²⁰⁸⁰ reduced preference is not due to altered gustatory responses to ethanol. (d) The reduced ethanol preference of rut²⁰⁸⁰ can be rescued by the induced expression of a rut cDNA in the nervous system using the elav-Geneswitch driver. In this experiment rutabaga expression was induced by RU486, resulting in significantly greater preference for 10% ethanol than that within the same genotype but vehicle-fed flies, and also more than the genotype rut²⁰⁸⁰;+;elav-GS/+ induced by RU486. The same treatment did not influence the ethanol preference in CS flies and the negative control flies, rut²⁰⁸⁰;+;elav-GS/+. Data are means ± S.E.M. *P<0.05, **P<0.01, and ***P<0.001.