Drosophila melanogaster transcriptional response to Nora virus infection

Abstract

Pathogens induce the activation and suppression of several genes, including potent immune response genes in Drosophila melanogaster. Although several different immune response pathways have been shown to play important roles in the defense against viruses, most of these responses are virus-specific and there appears to be no pathway or set of genes that are induced in response to all viruses. We have here identified genes that are differentially expressed in Drosophila melanogaster in response to Nora virus infection. Our results indicate that none of the known immune response pathways are induced following Nora virus infection, but among the upregulated genes we find three members of the same family as CHKov1 and CHKov2 (ref(3)D), which are involved in resistance to the σ virus. Although Nora virus is a known target of the RNAi pathway, none of the genes belonging to this antiviral system were affected. On the contrary, known immunity responders, such as targets of the Toll and Imd pathways, were downregulated. Several heat-shock proteins, which are usually activated in response to external stimuli, are induced during Nora virus infection. Strikingly, several stress response genes, chaperones and genes required for repair were induced, while digestive enzymes and proteins involved in nutrient uptake and transport were shut down