Comparative proteome analysis of skeletal muscle between Merino and Tsigai lambs

Proteomic methods allow detecting breed-specific differences at protein level. The objective of the present study was to compare muscle proteome profiles of Hungarian Merino and Tsigai sheep breeds by two dimensional gel electrophoresis and mass spectrometry based protein identification. Approximately 327 protein spots were detected in musculus longissimus dorsi and 14 protein spots, identified as 12 proteins, showed significant differences in their intensity (P < 0.05) between breeds. Seven and five proteins had higher expression in Merino and Tsigai skeletal muscle, respectively. Identified proteins were classified as structural, carbohydrate metabolism-related and miscellaneous ones. Six genes, which represent the three protein groups by function, were analysed by quantitative real-time PCR. All of the identified structural proteins have shown higher intensity in Merino, while the expression of identified glycolytic enzymes and myoglobin were higher in Tsigai lambs. One of the structural and one of the carbohydrate metabolism-related protein showed differences in expression at mRNA level by quantitative real-time PCR, as well. To the best of our knowledge, it was the first differential proteome analysis of sheep muscle and these results contribute to a better understanding of molecular differences between breeds.