Project name: Gallus gallus

Description: Obesity is a growing health concern in the United States and has been linked to a global epidemic--the metabolic syndrome. The purpose of this project was to use microarray analysis to unravel the genetic circuits controlling deposition and metabolism of fat in a hormonally-induced obesity model. Glucose, triglyceride, and free fatty acid levels of four-week-old chickens were dramatically altered after acute infusion (six days) of exogenous corticosterone (CS), effectively producing a fat phenotype. A lean phenotype was induced by thyroid hormone (T3), and the interaction of both hormones (CS+T3) was also examined. The Del-Mar 14K Chicken Integrated Systems Microarray (Geo Platform GPL1731) was used to identify differentially expressed hepatic genes (false discovery rate, P < 0.05). In the contrast of fat (CS) and lean (T3) phenotypes, 231 genes were up-regulated by CS, whereas 532 genes were up-regulated by T3. This study revealed several transport proteins, transcription factors, and metabolic enzymes that control lipogenic (CS induced) and lipolytic (T3 induced) pathways. Also, the divergent expression of three genes belonging to the ß-defensin family (DEFB9, DEFB10, and DEFB11) suggests a novel role for these antimicrobial peptides in adiposity. This project provides new insight into genetic control of metabolic disorders, such as diabetes and obesity.Keywords: Hormonal treatment on hepatic gene expression levelsOverall design: Six biological replicates each of the four treatment groups (except for five biological replicates for CS+T3) from four-week-old chickens given six days of hormonal treatment were analyzed for hepatic gene expression. Each of the 23 experimental samples was labeled with Alexa Fluor 555 and hybridized with an aliquot of the Alexa Fluor 647 reference RNA pool in a reference hybridization design.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: Agricultural

Release date: 2006-08-09

Last updated: 2006-06-30