title: Genetic ontogeny of pancreatic enzymes in Labrus bergylta larvae and the effect of feed type on enzyme activities and gene expression.
abstract: A newly cultivated wrasse species, Labrus bergylta, have shown great potential for use in Atlantic salmon (Salmo salar) farms in the battle against sea lice (Lepeoptheirus salmonis) infections. Hatchery reared L. bergylta were studied from 2 to 55 DPH to examine the molecular basis of digestive ontogeny related to the pancreas. An isolated feeding trial was performed on 27-34 DPH larvae to compare the effect of diet on enzyme activity and the possible exogenous contribution by live feed. The following genes coding for key pancreatic enzymes were analyzed by qPCR: trypsin, Cyp7 A1, BAL, sPLA(2) 1B, amylase and pancreatic chitinase. Enzyme activity was measured on trypsin, neutral lipase, sPLA(2), amylase and chitinase in fed and unfed larvae. We did not observe any effects of the formulated diet v.s. rotifers on enzyme activities of neutral lipase, chitinase and sPLA(2). However, a probable feed-dependency was observed at a transcriptional level, where rotifers seem to stimulate upregulation. The regulation of BAL was the only exception, where an upregulation was observed after weaning both in the ontogeny series and the experimental part. Our data on pancreatic chitinase and amylase mRNA levels suggest the importance of carbohydrates in the diet of early larval and juvenile L. bergylta.
authors.affiliation: National Institute of Nutrition and Seafood Research, PO Box 2029, Nordnes, 5817 Bergen, Norway.
authors.forename: Truls Wergeland
authors.initials: TW
authors.lastname: Hansen
authors.forename: Arild
authors.initials: A
authors.lastname: Folkvord
authors.forename: Espen
authors.initials: E
authors.lastname: Grøtan
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Sæle
mesh_terms: D000821:Animal Feed; D000818:Animals; D004798:Enzymes / Q000235:genetics* / Q000378:metabolism*; D005247:Feeding Behavior; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D007814:Larva / Q000201:enzymology / Q000235:genetics; D010179:Pancreas / Q000201:enzymology*; D010473:Perciformes / Q000235:genetics* / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D004798:Enzymes; D029941:Fish Proteins; D012333:RNA, Messenger