The Toll and Imd pathways are the major regulators of the immune response in Drosophila.
Microarray studies have shown recently that microbial infection leads to extensive changes in the Drosophila gene expression programme. However, little is known about the control of most of the fly immune-responsive genes, except for the antimicrobial peptide (AMP)-encoding genes, which are regulated by the Toll and Imd pathways. Here, we used oligonucleotide microarrays to monitor the effect of mutations affecting the Toll and Imd pathways on the expression programme induced by septic injury in Drosophila adults. We found that the Toll and Imd cascades control the majority of the genes regulated by microbial infection in addition to AMP genes and are involved in nearly all known Drosophila innate immune reactions. However, we identified some genes controlled by septic injury that are not affected in double mutant flies where both Toll and Imd pathways are defective, suggesting that other unidentified signalling cascades are activated by infection. Interestingly, we observed that some Drosophila immune-responsive genes are located in gene clusters, which often are transcriptionally co-regulated.
De Gregorio
Ennio
E
Centre de Génétique Moléculaire, CNRS, F-91198 Gif-sur-Yvette, France.
Spellman
Paul T
PT
Tzou
Phoebe
P
Rubin
Gerald M
GM
Lemaitre
Bruno
B
D000818:Animals; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster / Q000276:immunology* / Q000378:metabolism*; D005786:Gene Expression Regulation; D016678:Genome; D008954:Models, Biological; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000502:physiology*; D013997:Time Factors; D051193:Toll-Like Receptors; D014158:Transcription, Genetic
D029721:Drosophila Proteins; D011956:Receptors, Cell Surface; C068721:Tl protein, Drosophila; D051193:Toll-Like Receptors; C439909:imd protein, Drosophila