Comparative analysis of differentially expressed genes related to triglyceride metabolism between intramuscular fat and abdominal fat in broilers

Abstract

1. Lipid metabolism is an indispensable process in an organism, though little is known about the regulatory mechanisms of fat deposition in different types of adipose tissues. 2. The differentially expressed genes related to triglyceride (TG) metabolism between abdominal and intramuscular fat (IMF) of Beijing-You chickens were investigated in this study. 3. TG content in abdominal fat (AF) (349.7 mg/g) was significantly higher (P < 0.01) than in the breast and thigh (12.3 mg/g and 24.8 mg/g, respectively). 4. Using Agilent chicken gene-expression profiling in adipose tissues between AF and muscle (breast and thigh), certain representative genes related to fatty acid metabolism, lipoprotein catabolism and esterification reactions were significantly upregulated (P < 0.05 or P < 0.01). 5. Genes involved in fatty acid oxidation or carbohydrate utilisation were significantly up- or downregulated (P < 0.05 or P < 0.01), including those involved with highly enriched pathways of lipid metabolism (PPAR, Wnt pathway and inositol phosphate metabolism), cell junctions (focal adhesion and regulation of actin cytoskeleton) and muscle contraction. 6. Overall, higher TG levels were observed in AF tissue than in adipose tissues of breast and thigh, which could be regulated through gene expression of pathways related to lipid metabolism (PPAR, Wnt pathway and inositol phosphate metabolism), cell junctions (focal adhesion and regulation of actin cytoskeleton) and muscle contraction. These results provide clues to understanding the molecular mechanisms of TG metabolism between abdominal and IMF.

Keywords: Abdominal fat; broiler; genes; intramuscular fat; triglycerides.