Genomic and proteomic search for factors associated with fat accretion in broiler chickens
Increased fat deposition in poultry has been a major concern to poultry producers, processors and consumers alike. Recent studies have provided key information such as gene sequences and expression data and the effects of different nutrients on fat generation at transcription. However, these studies do not provide insight on factors associated with fat accretion at or post mRNA translation. It is the proteins that are the executants of most of the biological functions. In this study, it is hypothesized that chicken adiposity is highly influenced by factors beyond the genome. Therefore, the aim of this study was to employ a proteomics approach to identify proteins that may be associated with fat accretion in broiler chickens. One hundred and twenty 1-day-old broiler chickens (experiment 1, objective 1) and two hundred and twenty-six broiler chickens (experiment 2, objective 2) were randomly assigned to floor pens and fed standard broiler diet until 8 weeks. The control diet in experiment 2 was the same diet used in experiment 1. The diets used in experiment 1 consistent of 23% CP and 3,071 Kcal ME/kg diet and those of experiment 2consisted of 23% CP and 3,071 and 3,340 kcal ME/kg diet. The diet containing 3,340 kcal ME/kg was formulated to induce obesity in growing broilers, as reported on previous studies. In the 1st objective, experimental birds were sacrificed at 8 WOA and adipose tissue from the abdominal and visceral areas was collected, weighed and frozen in liquid nitrogen prior to storage at -80 oC until used. In the 2nd objective, animals were sacrificed (24 each) at 2, 4, 6, and 8 WOA. Adipose proteome from 16 birds (objective 1) and the birds from objective 2 with the highest and lowest abdominal fat percentage was assayed using two-dimensional differential gel electrophoresis (2D-DIGE) followed by in-gel digestion and Matrix Assisted Laser Desorption/ionization Time-of-Flight (MALDI-TOF) mass spectrometry. A total of 132 spots were found to be differentially expressed between the extreme birds (P<0.05). Among them was vimentin which was highly expressed in obese individuals. The mRNA abundance of vimentin was assayed using Real Time-Polymerase Chain Reaction. A student T-test revealed no significant differences (P>0.05) in the threshold cycles (Ct values) of vimentin in lean and obese birds. These results reveal that there may be factors beyond the genome that influence vimentin expression and possibly fat accretion in broilers.^
Biology, Molecular|Agriculture, General|Agriculture, Animal Culture and Nutrition
"Genomic and proteomic search for factors associated with fat accretion in broiler chickens"
ETD Collection for Tennessee State University.