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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-6-9
pubmed:databankReference
pubmed:abstractText
Fish are important sources of high quality protein, essential minerals such as iodine and selenium, vitamins including A, D and E, and omega-3 fatty acids in the human diet. With declining fisheries worldwide, farmed fish constitute an ever-increasing proportion of fish in the food basket. Sustainable development of aquaculture dictates that diets will have to contain increasing levels of plant products that are devoid of cholesterol, but contain phytosterols that are known to have physiological effects in mammals. Liver X receptors (LXR) are transcription factors whose activity is modulated by sterols, with activation inducing cholesterol catabolism and de novo fatty acid biosynthesis in liver. Transcriptomic analysis has shown that substitution of fish meal and oil with plant products induces genes of cholesterol and fatty acid metabolism in salmonids. Here we report the cloning of LXR cDNAs from two species of salmonid fish that are important in aquaculture. The full-length cDNA (mRNA) of LXR obtained from salmon was shown to be 3766 bp, which included a 5'-untranslated region (UTR) of 412 bp and a 3'-UTR of 1960 bp and an open reading frame (ORF) of 1394 bp, which specified a protein of 462 amino acids. The trout LXR full-length cDNA was 2056 bp, including 5'- and 3'-UTRs of 219 and 547 bp, respectively, and an ORF of 1290 bp, which specified a protein of 427 amino acids. The protein sequences included characteristic features of mammalian LXRs, including the DNA binding (DBD), containing P-box, ligand binding (LBD) and activation function-2 (AF-2) domains, D-box, D (hinge) region, and eight cysteines that belong to the two zinc fingers. Phylogenetic analysis clustered the salmonid LXRs together, more closely with zebrafish and more distantly from medaka and stickleback. A pair-wise comparison among vertebrate LXR sequences showed the amino acid sequence predicted by the salmon LXR ORF showed greatest identity to that of trout 97%, and 97%, 87% and 81% identity to LXRs of zebrafish, frog and human (LXRalpha). The trout LXR ORF showed 96%, 92% and 82% identity to LXRs of zebrafish, frog and human (LXRalpha). Surprisingly, the expression of LXR was lowest in liver of all tissues examined and in salmon the greatest expression was observed in pyloric caeca with liver showing intermediate expression. It is likely that tissue expression was affected by the physiological status of the sampled animals. Certainly, nutritional, environmental and/or developmental regulation was evident in salmon, where the expression of LXR in liver was higher in fish in seawater than in freshwater, and higher in fish fed fish oil compared to fish fed vegetable oil in adult salmon.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1879-1107
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
153
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
81-8
pubmed:meshHeading
pubmed-meshheading:19416695-Amino Acid Sequence, pubmed-meshheading:19416695-Animal Nutritional Physiological Phenomena, pubmed-meshheading:19416695-Animals, pubmed-meshheading:19416695-Cloning, Molecular, pubmed-meshheading:19416695-DNA, Complementary, pubmed-meshheading:19416695-Fish Oils, pubmed-meshheading:19416695-Fish Proteins, pubmed-meshheading:19416695-Fresh Water, pubmed-meshheading:19416695-Gene Expression Profiling, pubmed-meshheading:19416695-Gene Expression Regulation, pubmed-meshheading:19416695-Gene Expression Regulation, Developmental, pubmed-meshheading:19416695-Liver, pubmed-meshheading:19416695-Molecular Sequence Data, pubmed-meshheading:19416695-Oncorhynchus mykiss, pubmed-meshheading:19416695-Orphan Nuclear Receptors, pubmed-meshheading:19416695-Phylogeny, pubmed-meshheading:19416695-Plant Oils, pubmed-meshheading:19416695-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:19416695-Salmo salar, pubmed-meshheading:19416695-Seawater, pubmed-meshheading:19416695-Sequence Analysis, DNA, pubmed-meshheading:19416695-Sequence Homology, Amino Acid, pubmed-meshheading:19416695-Species Specificity, pubmed-meshheading:19416695-Transcription Factors
pubmed:year
2009
pubmed:articleTitle
Molecular cloning, tissue expression and regulation of liver X receptor (LXR) transcription factors of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss).
pubmed:affiliation
Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain. lourdescruzg@gmail.com
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't