title: Drosophila anti-nematode and antibacterial immune regulators revealed by RNA-Seq.
abstract: BACKGROUND
  Drosophila melanogaster activates a variety of immune responses against microbial infections. However, information on the Drosophila immune response to entomopathogenic nematode infections is currently limited. The nematode Heterorhabditis bacteriophora is an insect parasite that forms a mutualistic relationship with the gram-negative bacteria Photorhabdus luminescens. Following infection, the nematodes release the bacteria that quickly multiply within the insect and produce several toxins that eventually kill the host. Although we currently know that the insect immune system interacts with Photorhabdus, information on interaction with the nematode vector is scarce.
  
  
  RESULTS
  Here we have used next generation RNA-sequencing to analyze the transcriptional profile of wild-type adult flies infected by axenic Heterorhabditis nematodes (lacking Photorhabdus bacteria), symbiotic Heterorhabditis nematodes (carrying Photorhabdus bacteria), and Photorhabdus bacteria alone. We have obtained approximately 54 million reads from the different infection treatments. Bioinformatic analysis shows that infection with Photorhabdus alters the transcription of a large number of Drosophila genes involved in translational repression as well in response to stress. However, Heterorhabditis infection alters the transcription of several genes that participate in lipidhomeostasis and metabolism, stress responses, DNA/protein synthesis and neuronal functions. We have also identified genes in the fly with potential roles in nematode recognition, anti-nematode activity and nociception.
  
  
  CONCLUSIONS
  These findings provide fundamental information on the molecular events that take place in Drosophila upon infection with the two pathogens, either separately or together. Such large-scale transcriptomic analyses set the stage for future functional studies aimed at identifying the exact role of key factors in the Drosophila immune response against nematode-bacteria complexes.
authors.affiliation: Insect Infection and Immunity Lab, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC, 20052, USA. juliocastillo25@gmail.com.|Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD, 20852, USA. juliocastillo25@gmail.com.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Castillo
authors.affiliation: Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. toddcreasy@gmail.com.
authors.forename: Todd
authors.initials: T
authors.lastname: Creasy
authors.affiliation: Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. pkumari@som.umaryland.edu.
authors.forename: Priti
authors.initials: P
authors.lastname: Kumari
authors.affiliation: Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. ashetty@som.umaryland.edu.
authors.forename: Amol
authors.initials: A
authors.lastname: Shetty
authors.affiliation: Insect Infection and Immunity Lab, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC, 20052, USA. upasana@gwu.edu.
authors.forename: Upasana
authors.initials: U
authors.lastname: Shokal
authors.affiliation: Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA. ljtallon@som.umaryland.edu.
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Tallon
authors.affiliation: Insect Infection and Immunity Lab, Department of Biological Sciences, Institute for Biomedical Sciences, The George Washington University, Washington DC, 20052, USA. ioannise@gwu.edu.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Eleftherianos
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000276:immunology; D001424:Bacterial Infections / Q000235:genetics* / Q000276:immunology*; D019295:Computational Biology; D004331:Drosophila melanogaster / Q000235:genetics* / Q000276:immunology*; D009349:Nematode Infections / Q000235:genetics* / Q000276:immunology*; D020637:Photorhabdus / Q000276:immunology*; D012313:RNA / Q000235:genetics; D017423:Sequence Analysis, RNA / Q000379:methods; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D012313:RNA