title: Transcriptome and peptidome characterisation of the main neuropeptides and peptidic hormones of a euphausiid: the Ice Krill, Euphausia crystallorophias.
abstract: BACKGROUND
  The Ice krill, Euphausia crystallorophias is one of the species at the base of the Southern Ocean food chain. Given their significant contribution to the biomass of the Southern Ocean, it is vitally important to gain a better understanding of their physiology and, in particular, anticipate their responses to climate change effects in the warming seas around Antarctica.
  
  
  RESULTS
  Illumina sequencing was used to produce a transcriptome of the ice krill. Analysis of the assembled contigs via two different methods, produced 36 new pre-pro-peptides, coding for 61 neuropeptides or peptide hormones belonging to the following families: Allatostatins (A, B et C), Bursicon (α and β), Crustacean Hyperglycemic Hormones (CHH and MIH/VIHs), Crustacean Cardioactive Peptide (CCAP), Corazonin, Diuretic Hormones (DH), the Eclosion Hormone (EH), Neuroparsin, Neuropeptide F (NPF), small Neuropeptide F (sNPF), Pigment Dispersing Hormone (PDH), Red Pigment Concentrating Hormone (RPCH) and finally Tachykinin. LC/MS/MS proteomics was also carried out on eyestalk extracts, which are the major site of neuropeptide synthesis in decapod crustaceans. Results confirmed the presence of six neuropeptides and six precursor-related peptides previously identified in the transcriptome analyses.
  
  
  CONCLUSIONS
  This study represents the first comprehensive analysis of neuropeptide hormones in a Eucarida non-decapod Malacostraca, several of which are described for the first time in a non-decapod crustacean. Additionally, there is a potential expansion of PDH and Neuropeptide F family members, which may reflect certain life history traits such as circadian rhythms associated with diurnal migrations and also the confirmation via mass spectrometry of several novel pre-pro-peptides, of unknown function. Knowledge of these essential hormones provides a vital framework for understanding the physiological response of this key Southern Ocean species to climate change and provides a valuable resource for studies into the molecular phylogeny of these organisms and the evolution of neuropeptide hormones.
authors.affiliation: UPMC University of Paris 06, UMR 7144 CNRS, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France ; Centre National de la Recherche Scientifique, UMR 7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Toullec
authors.forename: Erwan
authors.initials: E
authors.lastname: Corre
authors.forename: Benoît
authors.initials: B
authors.lastname: Bernay
authors.forename: Michael A S
authors.initials: MA
authors.lastname: Thorne
authors.forename: Kévin
authors.initials: K
authors.lastname: Cascella
authors.forename: Céline
authors.initials: C
authors.lastname: Ollivaux
authors.forename: Joël
authors.initials: J
authors.lastname: Henry
authors.forename: Melody S
authors.initials: MS
authors.lastname: Clark
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000864:Antarctic Regions; D018533:Biomass; D016000:Cluster Analysis; D033201:Euphausiacea / Q000235:genetics* / Q000502:physiology*; D015723:Gene Library; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry*; D009792:Oceans and Seas; D036361:Peptide Hormones / Q000235:genetics*; D010802:Phylogeny; D020543:Proteome; D040901:Proteomics; D017386:Sequence Homology, Amino Acid; D059467:Transcriptome
chemical_list: D009479:Neuropeptides; D036361:Peptide Hormones; D020543:Proteome; C076523:allatostatin; C076101:neuropeptide F