title: Dietary fatty acid composition affects food intake and gut-brain satiety signaling in Senegalese sole (Solea senegalensis, Kaup 1858) larvae and post-larvae.
abstract: Little is known how dietary lipids affect food intake during larval development of fish, especially with regard to fatty acid (FA) composition. In fact, very little work has been done on appetite regulation and food intake in fish larvae in general, due to biological and technical difficulties associated with this type of studies. A new method using fluorescent microspheres as markers was developed in this study to evaluate food intake and prey selectivity of Senegalese sole larvae and post-larvae. Food intake was quantified in fish fed Artemia metanauplii enriched with oils differing in FA profile: cod liver oil (CLO), linseed oil (LSO), soybean oil (SBO) or olive oil (OO). The fish did not preferentially ingest a specific diet when presented with a choice. However, pre-metamorphic larvae from the CLO treatment ingested more metanauplii per g body weight, while differences in post-larvae were not significant. These findings were developed further by analyzing mRNA levels of a range of putative anorexigenic (pyya, pyyb, glp1, cckl, cart1a, cart1b, cart2a, cart4, pomca, pomcb, crf) and orexigenic (gal, npy, agrp2) genes, to identify those which are significantly affected by feeding and/or dietary FA composition. The variety of expression patterns observed highlighted the complexity of appetite regulatory mechanisms. In general, fish fed the CLO diet tended to show gene expression patterns most dissimilar to the remaining treatments. Expression in pre-metamorphic larvae was generally less in accordance with the putative function of the genes than in post-larvae, which could suggest a yet underdeveloped regulatory system.
authors: IRTA, Ctra. Poble Nou Km 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: kruno.bonacic@gmail.com.
authors: Kruno
authors: K
authors: Bonacic
authors: IRTA, Ctra. Poble Nou Km 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: cindy.campoverde@irta.cat.
authors: Cindy
authors: C
authors: Campoverde
authors: Institut de Recerca Biomédica de Lleida, Universitat de Lleida, 25198 Lleida, Spain. Electronic address: xga@medicina.udl.cat.
authors: Javier
authors: J
authors: Gómez-Arbonés
authors: IRTA, Ctra. Poble Nou Km 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: enric.gisbert@irta.cat.
authors: Enric
authors: E
authors: Gisbert
authors: IRTA, Ctra. Poble Nou Km 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: alicia.estevez@irta.cat.
authors: Alicia
authors: A
authors: Estevez
authors: IRTA, Ctra. Poble Nou Km 5.5, 43540 Sant Carles de la Ràpita, Spain. Electronic address: sofia.morais@lucta.com.
authors: Sofia
authors: S
authors: Morais
mesh_terms: D000818:Animals; D001069:Appetite Regulation / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004032:Diet; D004435:Eating; D005227:Fatty Acids / Q000494:pharmacology*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005412:Flatfishes / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D005227:Fatty Acids; D029941:Fish Proteins; D012333:RNA, Messenger
keywords: Appetite; Flow cytometry; Fluorescent microspheres; Gastrointestinal peptide; Live feed; Neuropeptide; Selectivity