title: Metabolic and proteomic profiling of diapause in the aphid parasitoid Praon volucre.
abstract: BACKGROUND
  Diapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and biochemical modifications underlying diapause in non-model organisms.
  
  
  RESULTS
  In this study we focused on the parasitic wasp, Praon volucre that exhibits a pupal diapause in response to environmental signals. System-wide metabolic changes occurring during diapause were investigated using GC-MS metabolic fingerprinting. Moreover, proteomic changes were studied in diapausing versus non-diapausing phenotypes using a combination of two-dimensional differential gel electrophoresis (2D-DIGE) and mass spectrometry. We found a reduction of Krebs cycle intermediates which most likely resulted from the metabolic depression. Glycolysis was galvanized, probably to favor polyols biosynthesis. Diapausing parasitoids accumulated high levels of cryoprotective polyols, especially sorbitol. A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes.
  
  
  CONCLUSIONS
  The results presented here provide some first clues about the molecular and biochemical events that characterize the diapause syndrome in aphid parasitoids. These data are useful for probing potential commonality of parasitoids diapause with other taxa and they will help creating a general understanding of diapause underpinnings and a background for future interpretations.
authors.affiliation: Earth and Life Institute ELI, Biodiversity Research Centre BDIV, Catholic University of Louvain, Louvain-la-Neuve, Belgium. herve.colinet@uclouvain.be
authors.forename: Hervé
authors.initials: H
authors.lastname: Colinet
authors.forename: David
authors.initials: D
authors.lastname: Renault
authors.forename: Blandine
authors.initials: B
authors.lastname: Charoy-Guével
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Com
mesh_terms: D000818:Animals; D001042:Aphids / Q000254:growth & development* / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D008401:Gas Chromatography-Mass Spectrometry; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D019476:Insect Proteins / Q000378:metabolism; D040901:Proteomics / Q000379:methods*
chemical_list: D019476:Insect Proteins