1a. Objectives (from AD-416):
Identify and characterize differentially expressed serum proteins and peptides associated with poultry metabolic skeletal problems such as femoral head separation (FHS) and tibial dyschondroplasia (TD).
1b. Approach (from AD-416):
Sera collected from FHS and TD-affected chickens, along with normal sera, will be analyzed to identify differentially occurring proteins and peptides. Low abundance proteins will be enriched while high abundance will be depleted using a library of hexapeptide-based affinity matrix called ProteoMiner. The proteins will be analyzed by 2D gel electrophoresis and characterized by peptide mass fingerprints and tandem mass spectrometry. The peptides will be enriched by solid phase extraction on C18 magnetic beads and analyzed by matrix-assisted laser desorption-time of flight (MALDI-TOF) mass spectrometry. The characterization of the peptides will be done using tandem mass spectrometry. The identification of both proteins and peptides will be done using MASCOT and/or other similar data base search.
3. Progress Report:
Poultry develop leg problems, one of which is femoral head necrosis (FHN) leading to the separation of femur from pelvic joint. It is a metabolic disease. Biomarker-based identification or prognostication of subclinical disease may result in better genetic selection. Comparing breeder chickens with or without femoral head separation problems, we examined serum peptides using proteomic techniques and identified elevated levels of 2 high density lipoprotein (HDL) degradation peptides in the blood of birds with disease. We also developed methods to analyze and distinguish proteomic changes using cartilage cells treated with a chemical pesticide, thiram, that causes another poultry leg problems called tibial dyschondroplasia. These techniques will help identify differentially expressed proteins and peptides for future studies with biomarkers.