In Drosophila, bacterial and fungal infection results in an innate immune response that engages the Toll, Imd, and melanization pathways (Brennan and Anderson, 2004). Toll and Imd signal transduction pathways are similar to the Toll-like and tumor necrosis factor pathways in vertebrates, respectively, and both converge on members of the nuclear factor-κB (NFκB) family of transcriptional regulators. In our microarray experiment, ethanol exposure resulted in increased expression of immunity genes of the Toll (cact, Myd88, Tl), Imd (imd, Rel), and melanization (Spn27A) pathways (Fig. S2). Additionally, a small subset of genes of unknown function that are induced by bacterial infection were also induced by ethanol exposure (IM2, IM10, IM23; Uttenweiler-Joseph et al., 1998). The temporal patterns of gene expression induction segregated into 2 classes: an early and transient induction and a slowly increasing induction. Interestingly, genes in the Toll and Imd pathway all showed the early and transient pattern of induction. These data suggest that expression of the Toll and Imd pathways may be coordinately regulated by ethanol exposure.
