title: Identification, tissue distribution and orexigenic activity of neuropeptide F (NPF) in penaeid shrimp.
abstract: The neuropeptide Fs (NPFs) are an invertebrate subgroup of the FMRFamide-like peptides, and are proposed by some to be the homologs of vertebrate neuropeptide Y. Although there is some information about the identity, tissue distribution and function of NPFs in insects, essentially nothing is known about them in crustaceans. We have identified and characterized NPF-encoding transcripts from the penaeid shrimp Litopenaeus vannamei and Melicertus marginatus. Two transcripts were identified from each species. For each shrimp species, the two transcripts differed from one another by the presence or absence of an insert in the portion of the open reading frame that encodes the NPF peptide. The two NPF isoforms are identical in L. vannamei and M. marginatus, with their predicted structures being KPDPSQLANMAEALKYLQELDKYYSQVSRPRFamide and KPDPSQLANMAEALKYLQELDKYYSQVSRPSPRSAPGPASQIQALENTLKFLQLQELGKLYSLRARPRFamide. RT-PCR tissue profiling showed both transcripts are broadly distributed within the nervous system of each species. The transcript encoding the shorter NPF was detected in some, but not all, midgut samples. The transcript encoding the longer NPF was absent in the midgut of both species, and neither transcript was detected in their skeletal muscle. Juvenile L. vannamei fed on a diet supplemented with the shorter NPF exhibited a marked increase in food intake relative to control individuals that did not receive the supplement; the NPF-fed shrimp also showed a significant increase in growth relative to the control group. Our data suggest that NPF is present in both the nervous system and midgut of penaeid shrimp, functioning, at least in part, as a powerful orexigenic agent.
authors: Neuroscience Program, John W. and Jean C. Boylan Center for Cellular and Molecular Physiology, Mount Desert Island Biological Laboratory, PO Box 35, Old Bar Harbor Road, Salisbury Cove, Maine 04672, USA. achristi@mdibl.org
authors: Andrew E
authors: AE
authors: Christie
authors: M Christine
authors: MC
authors: Chapline
authors: James M
authors: JM
authors: Jackson
authors: Jenilee K
authors: JK
authors: Dowda
authors: Niko
authors: N
authors: Hartline
authors: Spencer R
authors: SR
authors: Malecha
authors: Petra H
authors: PH
authors: Lenz
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001067:Appetite Depressants / Q000008:administration & dosage / Q000494:pharmacology*; D001483:Base Sequence; D004032:Diet; D004435:Eating / Q000187:drug effects*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000008:administration & dosage / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D033561:Penaeidae / Q000033:anatomy & histology* / Q000502:physiology*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D014018:Tissue Distribution
chemical_list: D001067:Appetite Depressants; D009479:Neuropeptides; D020033:Protein Isoforms; D011498:Protein Precursors; C076101:neuropeptide F