Proteomic Comparison between Japanese Black and Holstein Cattle by Two-dimensional Gel Electrophoresis and Identification of Proteins

Differences of meat qualities between Japanese Black and Holstein have been known in Japan, however, the causative proteins and/or the genetic background have been unclear. The aim of this study was to identify candidate proteins causing differences of the meat qualities between the two breeds. Using technique of two-dimensional gel electrophoresis, protein profiling was compared from samples of the longissimus dorsi muscle and subcutaneous adipose tissue. Five protein spots were observed with different expression levels between breeds. By using LC-MS/MS analysis and Mascot program, three of them were identified as ankyrin repeat protein 2, phosphoylated myosin light chain 2 and mimecan protein. Subsequently, we compared the DNA coding sequences of three proteins between breeds to find any nucleotide substitution. However, there was no notable mutation which could affect pI or molecular mass of the proteins. The identified proteins may be responsible for different characteristics of the meat qualities between Japanese Black and Holstein cattle.