Molecular mechanism of dietary phospholipid requirement of Atlantic salmon, Salmo salar, fry

The phospholipid (PL) requirement in fish is revealed by enhanced performance when larvae are provided PL-enriched diets. To elucidate the molecular mechanism underlying PL requirement in Atlantic salmon, Salmo salar, were fed a minimal PL diet and tissue samples from major lipid metabolic sites wer...

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Bibliographic Details
Published in:Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids
Main Authors: Carmona-AntoƱanzas, Greta, Taylor, John, Martinez-Rubio, Laura, Tocher, Douglas R
Other Authors: European Commission, Institute of Aquaculture, orcid:0000-0003-4370-7922, orcid:0000-0002-8603-9410
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2015
Subjects:
Online Access:http://hdl.handle.net/1893/22283
https://doi.org/10.1016/j.bbalip.2015.08.006
http://dspace.stir.ac.uk/bitstream/1893/22283/1/Carmona%20et%20al%20Salmon%20PL%20Requirement%20paper%202%20%281%29%20%281%29.pdf
Description
Summary:The phospholipid (PL) requirement in fish is revealed by enhanced performance when larvae are provided PL-enriched diets. To elucidate the molecular mechanism underlying PL requirement in Atlantic salmon, Salmo salar, were fed a minimal PL diet and tissue samples from major lipid metabolic sites were dissected from fry and parr. In silico analysis and cloning techniques demonstrated that salmon possess a full set of enzymes for the endogenous production of PL. The gene expression data indicated that major PL biosynthetic genes of phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns) display lower expression in intestine during the early developmental stage (fry). This is consistent with the hypothesis that the intestine of salmon is immature at the early developmental stage with limited capacity for endogenous PL biosynthesis. The results also indicate that intact PtdCho, PtdEtn and PtdIns are required in the diet at this stage. PtdCho and sphimgomyelin constitute the predominant PL in chylomicrons, involved in the transport of dietary lipids from the intestine to the rest of the body. As sphingomyelin can be produced from PtdCho in intestine of fry, our findings suggest that supplementation of dietary PtdCho alone during early developmental stages of Atlantic salmon would be sufficient to promote chylomicron formation. This would support efficient transport of dietary lipids, including PL precursors, from the intestine to the liver where biosynthesis of PtdEtn, PtdSer, and PtdIns is not compromised as in intestine facilitating efficient utilisation of dietary energy and the endogenous production of membrane PL for the rapidly growing and developing animal.