Whole-genome expression profile analysis of Drosophila melanogaster immune responses

Abstract

Drosophila melanogaster is an established model organism for the study of host-pathogen interactions. The sequencing of its genome allowed the prediction of all the genes encoded in it and, consequently, enabled a more comprehensive view of its immune responses. Whole-genome transcription analyses of Drosophila response to bacteria, fungi, parasitoids and viruses allow a comparison of the response between different classes of microorganisms and between pathogens of the same class. Overall, there is great diversity in the immune responses but there are a few pathways that are frequently activated. These studies provide a better understanding of how the host resists the infection and responds to the associated damage. Moreover, the data give insights into how microorganisms can manipulate their host and successfully establish an infection.

Developmental arrest of Drosophila survival motor neuron (Smn) mutants accounts for differences in expression of minor intron-containing genes

“…Thus, changes in levels of these mRNAs appear to be a consequence of dSMN depletion. The Toll, Imd (Immune deficiency), JNK (c-Jun N-terminal kinase), and JAK-STAT (Janus kinase-signal transducer and activator of transcription) signaling pathways regulate expression of these transcripts in response to infectious and noninfectious stresses (Leclerc and Reichhart 2004;Biteau et al 2011;Teixeira 2012). For example, the mRNAs for AttacinA (AttA) and Drosocin (Dro) encode antimicrobial peptides that are normally increased in response to septic injury, but their expression has also been linked to noninfectious stressors (Sano et al 2005;Tsuzuki et al 2012).…”

Symbionts Commonly Provide Broad Spectrum Resistance to Viruses in Insects: A Comparative Analysis of Wolbachia Strains

“…It was argued in the past that Wolbachia infection may lead to the activation of immune pathways that in turn could limit the multiplication of other parasites. Previous studies in mosquitoes showed that even if Wolbachia can prime the host immune system and increase antiviral resistance, such an effect is absent in D. melanogaster [44], [50], [51], [55], and flies deficient in both the Toll and IMD pathways still display Wolbachia -mediated resistance [54]. In agreement with previous studies, our results support the conclusion that Toll and IMD pathways are not required for antiviral protection since both Drosomycin and Diptericin expression level (reporters of Toll and IMD pathways respectively) were uncorrelated to the survival of virus-infected flies.…”

“…While this was shown to occur after transinfection of Wolbachia from Drosophila into Ae. aegypti and Anopheles gambiae [33], [48]–[50], such an effect was not observed in D. melanogaster naturally infected with Wolbachia [50]–[55] or transinfected with a non-native strain [44]. Similarly, the small interfering RNA (siRNA) pathway, which provides broad-spectrum antiviral defense in insects, is not required for Wolbachia to confer antiviral protection in flies [56].…”

Methods to study Drosophila immunity

“…Microarrays represent a rich source of co-regulated genes in different tissues and infectious conditions, and have been comprehensively reviewed in [65]. The Pathogen Associated Drosophila MicroArray (PADMA) database (www.padmadatabase.org) regroups accessible microarray data sets from a variety of immune challenges [66].…”