Effect of dietary supplementation with Spirulina on the expressions of AANAT, ADRB3, BTG2 and FASN genes in the subcutaneous adipose and Longissimus dorsi muscle tissues of purebred and crossbred Australian sheep

다국어 초록 (Multilingual Abstract)

Background: The demand for healthy, lean and consistent meat products containing low saturated fatty acidcontent and high quality polyunsaturated fatty acids (PUFA), especially long-chain (≥C20) omega-3 PUFA, hasincreased in recent times. Fat deposition is altered by both the genetic background and dietary supplements, andthis study aimed to assess the effect of dietary Spirulina supplementation levels on the mRNA expression patternsof genes controlling lipid metabolism in the subcutaneous adipose tissue (SAT) and Longissimus dorsi (ld) muscle ofAustralian crossbred sheep.
Methods: Twenty-four weaned lambs belonging to four breeds under the same management conditions weremaintained on ryegrass pasture and fed three levels of Spirulina supplement (control, low and high). In terms ofnutrient composition, Spirulina is a nutrient-rich supplement that contains all essential amino acids, vitamins andminerals. It also is a rich source of carotenoids and fatty acids, especially gamma-linolenic acid (GLA) that inferhealth benefits. After slaughter, subcutaneous adipose tissue (SAT) and ld samples were subjected to mRNAextraction and reverse transcription using quantitative polymerase chain reaction (RT-qPCR) to assess the mRNAexpression levels of the Aralkylamine N-acetyltransferase (AANAT), Adrenergic beta-3 receptor (ADRB3), B-celltranslocation gene 2 (BTG2) and Fatty acid synthase (FASN) genes, which are associated with lipid metabolism.
Results: Both low and high Spirulina supplementation levels strongly up-regulated the transcription of all theselected genes in both SAT and ld tissues (mostly in the subcutaneous adipose), but sheep breed and sex did notinfluence the gene expression patterns in these tissues.
Conclusions: The evidence indicates that high Spirulina supplementation level resulted in a decrease inintramuscular fat content in Australian purebred and crossbred sheep due to the enhanced production ofmelatonin in sheep muscle tissues and strong up-regulation of mRNA expression of BTG2 in SAT which negativelyaffected fat deposition. In contrast, low Spirulina supplementation level strongly up-regulated the ADRB3 and FASNgenes responsible for fat production. These findings are consistent with the observed phenotypic data suggestingthat low Spirulina supplementation level can increase lamb production, with higher long-chain PUFA content.

참고문헌 (Reference)

1 Strosberg AD, "Structure and function of the β3-adrenergic receptor" 37 : 421-450, 1997

2 Holman BWB, "Spirulina as a livestock supplement and animal feed" 97 : 615-623, 2013

3 Wu J, "SNP variation in ADRB3 gene reflects the breed difference of sheep populations" 39 : 8395-8403, 2012

4 Hu J, "Polymorphism of the bovine ADRB3 gene" 37 : 3389-3392, 2010

5 Forrest RH, "Polymorphism at the ovine β3-adrenergic receptor locus(ADRB3)and its association with lamb mortality" 85 : 2801-2806, 2007

6 Forrest RH, "Polymorphism at the ovine β3-adrenergic receptor locus : associations with birth weight, growth rate, carcass composition and cold survival" 34 : 19-25, 2003

7 Boizard M, "Obesity-related overexpression of fatty-acid synthase gene in adipose tissue involves sterol regulatory element-binding protein transcription factors" 273 : 29164-29171, 1998

8 Deckelbaum RJ, "N − 3 fatty acids and gene expression" 83 : S1520-1525, 2006

9 Mo XY, "Molecular characterization, expression pattern and association analysis of the porcine BTG2 gene" 38 : 4389-4396, 2011

10 Reiter RJ, "Melatonin reduces lipid peroxidation and membrane viscosity : a review" 56 : 225-237, 2014

11 Jiménez-Aranda A, "Melatonin induces browning of inguinal white adipose tissue in Zucker diabetic fatty rats" 55 : 416-423, 2013

12 Higuchi R, "Kinetic PCR analysis : Real-time monitoring of DNA amplification reactions" 11 : 1026-1030, 1993

13 Holman B, "Growth and body conformation responses of genetically divergent Australian sheep to Spirulina(Arthrospira platensis)supplementation" 2 : 160-173, 2012

14 Roy R, "Genomic structure and alternative transcript of bovine fatty acid synthase gene FASN : comparative analysis of the FASN gene between monogastric and ruminant species" 111 : 65-73, 2005

15 Clément K, "Genetic variation in the β3-adrenergic receptor and an increased capacity to gain weight in patients with morbid obesity" 333 : 352-354, 1995

16 Coon SL, "Genetic variability in plasma melatonin in sheep is due to pineal weight, not to variations in enzyme activities" 227 : 792-797, 1999

17 Perez R, "Genes associated with long-chain omega-3 fatty acids in bovine skeletal muscle" 51 : 479-487, 2010

18 Berndt J, "Fatty acid synthase gene expression in human adipose tissue : association with obesity and type 2 diabetes" 50 : 1472-1480, 2007

19 Da Costa A, "Expression of genes controlling fat deposition in two genetically diverse beef cattle breeds fed high or low silage diets" 9 : 118-, 2013

20 Holman BWB, "Effects of Spirulina(Arthrospira platensis)supplementation level and basal diet on liveweight, body conformation and growth traits in genetically divergent Australian dual-purpose lambs during simulated drought and typical pasture grazing" 120 : 6-1, 2014

21 Wu J, "Distribution and quantification of β-3adrenergic receptor in tissues of sheep" 5 : 88-93, 2011

22 Bichi E, "Dietary marine algae and its influence on tissue gene network expression during milk fat depression in dairy ewes" 186 : 36-44, 2013

23 Kamaid A, "BTG1 and BTG2 gene expression during early chick development" 237 : 2158-2169, 2008

24 Pfaffl MW, "A new mathematical model for relative quantification in real-time RT–PCR" 29 : e45-, 2001

25 Guo B, "A gene expression estimator of intramuscular fat percentage for use in both cattle and sheep" 5 : 35-, 2014

26 Coon SL, "87)gene(AANAT) : structure, chromosomal localization, and tissue expression" 34 : 76-84, 1996