title: Genomics, transcriptomics, and peptidomics of Daphnia pulex neuropeptides and protein hormones.
abstract: We report 43 novel genes in the water flea Daphnia pulex encoding 73 predicted neuropeptide and protein hormones as partly confirmed by RT-PCR. MALDI-TOF mass spectrometry identified 40 neuropeptides by mass matches and 30 neuropeptides by fragmentation sequencing. Single genes encode adipokinetic hormone, allatostatin-A, allatostatin-B, allatotropin, Ala(7)-CCAP, CCHamide, Arg(7)-corazonin, DENamides, CRF-like (DH52) and calcitonin-like (DH31) diuretic hormones, two ecdysis-triggering hormones, two FIRFamides, one insulin, two alternative splice forms of ion transport peptide (ITP), myosuppressin, neuroparsin, two neuropeptide-F splice forms, three periviscerokinins (but no pyrokinins), pigment dispersing hormone, proctolin, Met(4)-proctolin, short neuropeptide-F, three RYamides, SIFamide, two sulfakinins, and three tachykinins. There are two genes for a preprohormone containing orcomyotropin-like peptides and orcokinins, two genes for N-terminally elongated ITPs, two genes (clustered) for eclosion hormones, two genes (clustered) for bursicons alpha, beta, and two genes (clustered) for glycoproteins GPA2, GPB5, three genes for different allatostatins-C (two of them clustered) and three genes for IGF-related peptides. Detailed comparisons of genes or their products with those from insects and decapod crustaceans revealed that the D. pulex peptides are often closer related to their insect than to their decapod crustacean homologues, confirming that branchiopods, to which Daphnia belongs, are the ancestor group of insects.
authors.affiliation: Department of Zoology, Stockholm University, Sweden. dircksen@zoologi.su.se
authors.forename: Heinrich
authors.initials: H
authors.lastname: Dircksen
authors.forename: Susanne
authors.initials: S
authors.lastname: Neupert
authors.forename: Reinhard
authors.initials: R
authors.lastname: Predel
authors.forename: Peter
authors.initials: P
authors.lastname: Verleyen
authors.forename: Jurgen
authors.initials: J
authors.lastname: Huybrechts
authors.forename: Johannes
authors.initials: J
authors.lastname: Strauss
authors.forename: Frank
authors.initials: F
authors.lastname: Hauser
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Stafflinger
authors.forename: Martina
authors.initials: M
authors.lastname: Schneider
authors.forename: Kevin
authors.initials: K
authors.lastname: Pauwels
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
authors.forename: Cornelis J P
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
mesh_terms: D054392:Adipokines / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D019295:Computational Biology / Q000379:methods; D003621:Daphnia; D020224:Expressed Sequence Tags; D005260:Female; D023281:Genomics; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D059467:Transcriptome
chemical_list: D054392:Adipokines; D009479:Neuropeptides; D010455:Peptides; D011506:Proteins