Mutations in Bacchus reveal a tyramine-dependent nuclear regulator for acute ethanol sensitivity in Drosophila

► Loss-of-function mutations in the Bacchus gene reduced ethanol sensitivity in Drosophila. ► Ethanol insensitivity of Bacchus mutant flies is mediated by increased activity of tyramine-β-hydroxylase. ► Feeding tyramine to Bacchus mutant flies restored normal ethanol sensitivity.