intermediate 3-phosphoglycerate in a 3-step enzymatic process; the Drosophila gene astray encodes the terminal enzyme 3-phosphoserine phosphatase. Serine is also synthesized from glycine by glycine hydroxylmethyltransferase, which is encoded by the Drosophila gene CG3011.Serine racemase converts l-serine to d-serine (Oliet and Mothet, 2009) and is encoded by the Drosophila gene CG8129. While d-serine has not yet been described as a neurotransmitter in flies, coregulation of the biosynthetic enzymes by ethanol raises the possibility that d-serine contributes to ethanol responding. Finally, we note the ethanol-induced down-regulation of the high mobility group protein gene HmgZ that is predicted to regulate chromatin structure, and of the lipophorin protein gene Rfabg that has been implicated in long range intercellular signaling (Panakova et al., 2005; Ragab et al., 2006). Ethanol-regulated genes in common with our study and one other study include those encoding DNA-binding proteins (CTCF, fkh, odd, Side), chromatin structure (mbf1, Rpd3), signal transduction (Akap200, Cks85A, mats, Pp1alpha-96A, Ptr, tsl), innate immunity (dnr1, dro5, Spn27A), and many other genes whose products are known or predicted to function in lipid and other metabolic pathways (Table S4). Finally, we note that the genes identified in the 2 previous studies show greater overlap with our set of
