The whole animal, and the pectoralis muscle in particular, grows at a greatly enhanced rate in
chickens selected for meat production (broilers) when compared to those selected for egg
production (layers). As part of an ongoing study to analyse muscle protein dynamics under
conditions of rapid growth, we have embarked upon a preliminary characterisation of the proteome
of layer chicken pectoralis muscle, at specified time-points from 1 to 27 days after
hatching. Soluble extracts of muscle homogenates were separated by two-dimensional (2-D)
gel electrophoresis and selected spots were analysed by in-gel tryptic digestion and matrix
assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry. Of 90
spots, 51 gave mass spectra that matched to existing chicken proteins present in on-line
databases, 12 matched equivalent proteins from non-avian species and 11 yielded good quality
spectra but were unable to be matched against existing databases. For many of these
proteins, growth over 27 days elicited dramatic changes in relative expression levels. Chicken
skeletal muscle offers an excellent system for developmental proteomics.