Project description:Excessive accumulation of lipids in the adipose tissue is a major problem in the present-day broiler industry. However, few studies have analyzed the expression of adipose tissue genes that are involved in pathways and mechanisms leading to adiposity in chickens. Gene expression profiling of chicken adipose tissue could provide key information about the ontogenesis of fatness and clarify the molecular mechanisms underlying obesity. Chicken Genome Arrays were used to construct an adipose tissue gene expression profile of 7-week-old broilers, and to screen adipose tissue genes that are differentially expressed in lean and fat lines divergently selected over eight generations for high and low abdominal fat weight. Keywords: two lines comparison
Project description:Domestic broiler chickens rapidly accumulate adipose tissue due to intensive genetic selection for rapid growth and are naturally hyperglycemic and insulin resistant, making them an attractive addition to the suite of rodent models used for studies of obesity and type 2 diabetes in humans. Furthermore, chicken adipose tissue is considered as poorly sensitive to insulin and lipolysis is under glucagon control. Excessive fat accumulation is also an economic and environmental concern for the broiler industry due to the loss of feed efficiency and excessive nitrogen wasting, as well as a negative trait for consumers who are increasingly conscious of dietary fat intake. Understanding the control of avian adipose tissue metabolism would both enhance the utility of chicken as a model organism for human obesity and insulin resistance and highlight new approaches to reduce fat deposition in commercial chickens. In the present study we simultaneously characterized the effects of a short term (5 hours) fast or neutralization of insulin action (5 hours) on adipose tissue of young (16-17 day-old), fed commercial broiler chickens.
Project description:Domestic broiler chickens rapidly accumulate adipose tissue due to intensive genetic selection for rapid growth and are naturally hyperglycemic and insulin resistant, making them an attractive addition to the suite of rodent models used for studies of obesity and type 2 diabetes in humans. Furthermore, chicken adipose tissue is considered as poorly sensitive to insulin and lipolysis is under glucagon control. Excessive fat accumulation is also an economic and environmental concern for the broiler industry due to the loss of feed efficiency and excessive nitrogen wasting, as well as a negative trait for consumers who are increasingly conscious of dietary fat intake. Understanding the control of avian adipose tissue metabolism would both enhance the utility of chicken as a model organism for human obesity and insulin resistance and highlight new approaches to reduce fat deposition in commercial chickens.
Project description:Excessive accumulation of lipids in the adipose tissue is a major problem in the present-day broiler industry. However, few studies have analyzed the expression of adipose tissue genes that are involved in pathways and mechanisms leading to adiposity in chickens. Gene expression profiling of chicken adipose tissue could provide key information about the ontogenesis of fatness and clarify the molecular mechanisms underlying obesity. Chicken Genome Arrays were used to construct an adipose tissue gene expression profile of 7-week-old broilers, and to screen adipose tissue genes that are differentially expressed in lean and fat lines divergently selected over eight generations for high and low abdominal fat weight. Experiment Overall Design: Birds were slaughtered at 7 weeks and abdominal fat was isolated, immediately frozen in liquid nitrogen and stored at -80oC. The ten birds used in the present study were chosen by the percentage of abdominal fat (AFP): five had the highest AFP and the other five had the lowest for RNA extraction and hybridization on Affymetrix microarrays..
Project description:Domestic chicken has been intensively studied because of its role as an efficient source of lean meat. However, commercial broilers resulting from genetic selection for rapid growth demonstrate detrimental traits, such as excess deposition of abdominal adipose tissue, metabolic disorders, and reduced reproduction. Therefore fast-growing broilers represent “obese” chickens compared to slow-growing egg layers (e.g, Leghorn) or wild strain of meat-type chickens (e.g., Fayoumi). Fayoumi chickens, originating from Egypt, represent a harder stain of chickens, which are more resistant to diseases. Leghorn chickens are the original breed of commercial U.S layers. Both lines were maintained highly inbred by Iowa State University poultry geneticists with an inbreeding coefficient higher than 0.95. Both Fayoumi and Leghorn demonstrated lean phenotype compared to broilers, and these three lines of chickens are genetically distant from each other.
Project description:Domestic chicken has been intensively studied because of its role as an efficient source of lean meat. However, commercial broilers resulting from genetic selection for rapid growth demonstrate detrimental traits, such as excess deposition of abdominal adipose tissue, metabolic disorders, and reduced reproduction. Therefore fast-growing broilers represent “obese” chickens compared to slow-growing egg layers (e.g, Leghorn) or wild strain of meat-type chickens (e.g., Fayoumi). Fayoumi chickens, originating from Egypt, represent a harder stain of chickens, which are more resistant to diseases. Leghorn chickens are the original breed of commercial U.S layers. Both lines were maintained highly inbred by Iowa State University poultry geneticists with an inbreeding coefficient higher than 0.95. Both Fayoumi and Leghorn demonstrated lean phenotype compared to broilers, and these three lines of chickens are genetically distant from each other. In this study, we used affymetrix microarray to profile global gene expression of three distinct genetic lines of chickens to identify functional pathways associated with leanness of domestic chickens.
Project description:Transcriptional profiling of the jejunum mucosa with 1.5 fold-change reporter genes in comparing control black-boned chickens under normal temperature (NT) conditon with heat-stress treated black-boned chickens under high temperature (HT) condition. Goal was to determine the differentially expressed genes (DEGs) in co-family black-boned chickens exposure to heat stress based on global chicken gene expression.
Project description:Adipose tissue is essential for lipid storage and thus, energy regulation and maintenance. Many organs in the body utilize lipids as their primary energy source, such as the heart. In addition, when glucose supplies are insufficient adipose tissue is broken down and fats are utilized systemically as a primary energy source. This is regulated by the endocrine system primarily through the regulation of glucagon and insulin. Adipose tissue is also involved with the immune system particularly in eliciting an inflammatory response through cytokine signaling and the release of interleukins. Chickens have two major fat pads: an abdominal fat pad and a cardiac fat pad. The abdominal fat pad is located on the ventral side, above the GI tract. The cardiac fat pad is situated on the atria of the heart and surrounds the aorta. These fat pads are different in coloration and size which leads to the hypothesis that these fat pads have different functions. The objectives of the project are to (a) identify genes that are unique to each type of adipose tissue when compared to the rest of the body, through the collection of other tissues and (b) to identify genes that are differentially expressed in each type of adipose tissue in comparison to each other to better understand the functioning of these fat pads in the chicken and the pathways that they are involved in at the transcriptomic level.
Project description:A better understanding of the regulation of gene expression and lipid metabolism in the chicken will benefit producers, as well as scientists who use the chicken as a model organism for studies of developmental biology and human therapeutics. We constructed the gene expression profiles of major chicken tissues to screened genes prominently high expressed in chicken adipose tissue and liver using the Chicken Genome arrays by comparing their expression profiles with twenty other tissue types. Our objectives have been to construct gene expression profiles of the major chicken tissues, identify genes prominently high expressed in chicken adipose tissue and liver than other tissues.