title: Proteomic and metabolomic profiles of larval hemolymph associated with diapause in the cotton bollworm, Helicoverpa armigera.
abstract: BACKGROUND
  Diapause is programmed developmental arrest coupled with the depression of metabolic activity and the enhancement of stress resistance. Pupal diapause is induced by environmental signals and is prepared during the prediapause phase. In the cotton bollworm, Helicoverpa armigera, the prediapause phase, which contains two sub-phases, diapause induction and preparation, occurs in the larval stage. Here, we performed parallel proteomic and metabolomic analyses on H. armigera larval hemolymph during the prediapause phase.
  
  
  RESULTS
  By two-dimensional electrophoresis, 37 proteins were shown to be differentially expressed in diapause-destined larvae. Of these proteins, 28 were successfully identified by MALDI-TOF/TOF mass spectrometry. Moreover, a total of 22 altered metabolites were found in diapause-destined larval hemolymph by GC-MS analysis, and the levels of 17 metabolites were elevated and 5 were decreased.
  
  
  CONCLUSIONS
  The proteins and metabolites with significantly altered levels play different roles in diapause-destined larvae, including diapause induction, metabolic storage, immune response, stress tolerance, and others. Because hemolymph circulates through the whole body of an insect, these differences found in diapause-destined larvae most likely correspond to upstream endocrine signals and would further influence other organ/tissue activities to determine the insect's fact: diapause or development.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yu-Xuan
authors.initials: YX
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China. xuweihua@mail.sysu.edu.cn.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Xu
mesh_terms: D000818:Animals; D064666:Diapause, Insect; D015180:Electrophoresis, Gel, Two-Dimensional; D008401:Gas Chromatography-Mass Spectrometry; D007814:Larva / Q000378:metabolism; D055442:Metabolome; D009036:Moths / Q000254:growth & development / Q000378:metabolism*; D025341:Principal Component Analysis; D020543:Proteome / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020543:Proteome