COMPARISON OF GENE EXPRESSION IN ABDOMINAL AND CARDIAC ADIPOSE TISSUE OF THE MODERN BROILER CHICKEN

Abstract

Adipose tissue is a major storage depot for lipids. The chicken has two main fat pads, the cardiac and abdominal fat pads. It is hypothesized that there is a difference in gene expression between the two types of adipose tissue, particularly in genes involved in lipid regulation, reflecting a difference in function. Illumina transcriptome libraries were prepared from Ross 708 market age modern broiler chicken abdominal and cardiac adipose samples. Bioinformatic analysis identified pathways common to both types adipose, unique to abdominal fat, and unique to cardiac fat. Energy homeostasis and lipid regulation appears to be the same in the abdominal and cardiac adipose. The maintenance of the extracellular matrix (ECM) and the microenvironment is also similar between both types of adipose with the cardiac adipose ECM appearing slightly more static. This could be because the cardiac adipose is not the primary lipid storage depot and thus less transport needs to take place within the tissue. The immune responses appear to be different between abdominal and cardiac adipose. The abdominal adipose appears to be slightly more pro-inflammatory while the cardiac adipose appears to be dampening inflammation. Both types of adipose regulate inflammation in unique ways. The abdominal adipose also appears to be upregulating endocytosis, supporting its role as the primary lipid storage depot of the body.