title: Identification of the main venom protein components of Aphidius ervi, a parasitoid wasp of the aphid model Acyrthosiphon pisum.
abstract: BACKGROUND
  Endoparasitoid wasps are important natural enemies of the widely distributed aphid pests and are mainly used as biological control agents. However, despite the increased interest on aphid interaction networks, only sparse information is available on the factors used by parasitoids to modulate the aphid physiology. Our aim was here to identify the major protein components of the venom injected at oviposition by Aphidius ervi to ensure successful development in its aphid host, Acyrthosiphon pisum.
  
  
  RESULTS
  A combined large-scale transcriptomic and proteomic approach allowed us to identify 16 putative venom proteins among which three γ-glutamyl transpeptidases (γ-GTs) were by far the most abundant. Two of the γ-GTs most likely correspond to alleles of the same gene, with one of these alleles previously described as involved in host castration. The third γ-GT was only distantly related to the others and may not be functional owing to the presence of mutations in the active site. Among the other abundant proteins in the venom, several were unique to A. ervi such as the molecular chaperone endoplasmin possibly involved in protecting proteins during their secretion and transport in the host. Abundant transcripts encoding three secreted cystein-rich toxin-like peptides whose function remains to be explored were also identified.
  
  
  CONCLUSIONS
  Our data further support the role of γ-GTs as key players in A. ervi success on aphid hosts. However, they also evidence that this wasp venom is a complex fluid that contains diverse, more or less specific, protein components. Their characterization will undoubtedly help deciphering parasitoid-aphid and parasitoid-aphid-symbiont interactions. Finally, this study also shed light on the quick evolution of venom components through processes such as duplication and convergent recruitment of virulence factors between unrelated organisms.
authors.forename: Dominique
authors.initials: D
authors.lastname: Colinet
authors.forename: Caroline
authors.initials: C
authors.lastname: Anselme
authors.forename: Emeline
authors.initials: E
authors.lastname: Deleury
authors.forename: Donato
authors.initials: D
authors.lastname: Mancini
authors.forename: Julie
authors.initials: J
authors.lastname: Poulain
authors.forename: Carole
authors.initials: C
authors.lastname: Azéma-Dossat
authors.forename: Maya
authors.initials: M
authors.lastname: Belghazi
authors.forename: Sophie
authors.initials: S
authors.lastname: Tares
authors.forename: Francesco
authors.initials: F
authors.lastname: Pennacchio
authors.forename: Marylène
authors.initials: M
authors.lastname: Poirié
authors.affiliation: INRA, ISA, UMR 1355, Evolution et Spécificité des Interactions Multitrophiques (ESIM), Sophia Antipolis, 06903, France. Jean-luc.Gatti@sophia.inra.fr.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Gatti
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000235:genetics / Q000378:metabolism / Q000469:parasitology; D020134:Catalytic Domain / Q000235:genetics; D020451:Contig Mapping; D020224:Expressed Sequence Tags; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D040901:Proteomics; D016415:Sequence Alignment; D057057:Serine Proteases / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome; D014862:Wasp Venoms / Q000737:chemistry* / Q000201:enzymology*; D014863:Wasps / Q000737:chemistry / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D005723:gamma-Glutamyltransferase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D008562:Membrane Glycoproteins; D014862:Wasp Venoms; C053387:endoplasmin; D005723:gamma-Glutamyltransferase; D057057:Serine Proteases