title: Regulation of feeding by Neuropeptide F in the desert locust, Schistocerca gregaria.
abstract: Our knowledge on the physiological function of the insect Neuropeptide F (NPF) mostly comes from studies in the fruit fly, Drosophila melanogaster, where NPF was shown to regulate diverse processes, such as feeding, learning and responding to stress. In the desert locust, Schistocerca gregaria, only a truncated form of the "full-length" NPF (the biologically active "trNPF") has been isolated. In this study, we investigated whether this peptide is involved in the regulation of feeding in this orthopteran species. In the S. gregaria EST-database, an NPF-precursor encoding transcript was found. Alignment with other insect NPF-precursors showed relatively highest sequence conservation within the trNPF region (and the flanking dibasic cleavage site), as compared to other regions of the NPF-precursor. Quantitative real-time RT-PCR revealed that the Schgr-NPF-precursor encoding transcript occurs throughout the central nervous system with relatively high transcript levels in the brain, optic lobes and suboesophageal ganglion. It was also detected at relatively high levels in the midgut, which suggests that the encoded peptide also functions in the digestive system. Moreover, Schgr-NPF-transcript levels were notably higher in starved animals than in animals fed ad libitum, while transcript levels were also shown to be regulated after the consumption of a meal. Injection of locust trNPF in adults stimulated food intake, while RNAi knockdown reduced food intake. Furthermore, injection of trNPF in adults stimulated weight increase, while RNAi knockdown reduced weight gain. This effect of trNPF on body weight gain may result from its stimulatory effect on food intake. Taken together, we provide clear evidence for an important role of trNPF in the regulation of feeding in the desert locust, S. gregaria.
authors.affiliation: Molecular Developmental Physiology and Signal Transduction, Department of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Naamsestraat 59, B-3000 Leuven, Belgium. pieter.vanwielendaele@bio.kuleuven.be
authors.forename: Pieter
authors.initials: P
authors.lastname: Van Wielendaele
authors.forename: Senne
authors.initials: S
authors.lastname: Dillen
authors.forename: Sven
authors.initials: S
authors.lastname: Zels
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Badisco
authors.forename: Jozef
authors.initials: J
authors.lastname: Vanden Broeck
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001835:Body Weight; D017124:Conserved Sequence; D004435:Eating; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005508:Food Deprivation; D006110:Grasshoppers / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D017422:Sequence Analysis, DNA
chemical_list: D009479:Neuropeptides; C076101:neuropeptide F