Genome-wide analysis of the Drosophila immune response by using oligonucleotide microarrays

To identify new Drosophila genes involved in the immune response, we monito red the gene expression profile of adult flies in response to microbial inf ection by using high-density oligonucleotide microarrays encompassing nearl y the full Drosophila genome. Of 13,197 genes tested, we have characterized 230 induced and 170 repressed by microbial infection, most of which had no t previously been associated with the immune response. Many of these genes can be assigned to specific aspects of the immune response, including recog nition, phagocytosis, coagulation, melanization, activation of NF-kappaB tr anscription factors, synthesis of antimicrobial peptides, production of rea ctive oxygen species, and regulation of iron metabolism. Additionally, we f ound a large number of genes with unknown function that may be involved in control and execution of the immune response. Determining the function of t hese genes represents an important challenge for improving our knowledge of innate immunity. Complete results may be found at http://www.fruitfly.org/ expression/immunity/.