Rimoldi S, Bossi E, Harpaz S, Cattaneo AG, Bernardini G, Saroglia M, Terova G. Intestinal B(0)AT1 (SLC6A19) and PEPT1 (SLC15A1) mRNA levels in European sea bass (Dicentrarchus labrax) reared in fresh water and fed fish and plant protein sources.
J Nutr Sci 2015;
4:e21. [PMID:
26097704 DOI:
10.1017/jns.2015.9]
[Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 01/08/2015] [Accepted: 02/18/2015] [Indexed: 01/11/2023] Open
Abstract
The objective of the present study was to examine the effect of diets with descending
fish meal (FM) inclusion levels and the addition of salt to the diet containing the lowest
FM level on growth performances, feed conversion ratio, and intestinal solute carrier
family 6 member 19 (SLC6A19) and oligopeptide transporter 1
(PEPT1) transcript levels, in freshwater-adapted European sea bass
(Dicentrarchus labrax). We first isolated by molecular cloning and
sequenced a full-length cDNA representing the neutral amino acid transporter SLC6A19 in
sea bass. The cDNA sequence was deposited in GenBank database (accession no. KC812315).
The twelve transmembrane domains and the ‘de novo’ prediction of the
three-dimensional structure of SLC6A19 protein (634 amino acids) are presented. We then
analysed diet-induced changes in the mRNA copies of SLC6A19 and
PEPT1 genes in different portions of sea bass intestine using real-time
RT-PCR. Sea bass were fed for 6 weeks on different diets, with ascending levels of fat or
descending levels of FM, which was replaced with vegetable meal. The salt-enriched diet
was prepared by adding 3 % NaCl to the diet containing 10 % FM. SLC6A19
mRNA in the anterior and posterior intestine of sea bass were not modulated by dietary
protein sources and salt supplementation. Conversely, including salt in a diet containing
a low FM percentage up-regulated the mRNA copies of PEPT1 in the hindgut.
Fish growth correlated positively with the content of FM in the diets. Interestingly, the
addition of salt to the diet containing 10 % FM improved feed intake, as well as specific
growth rate and feed conversion ratio.
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