Proteomic profile os skeletal muscle and liver tissue of high and low residual feed intake identified Nellore cattle

Abstract

Residual feed intake (RFI) has been extensively used to evaluate feed efficiency, however the molecular underlying differences in this trait remains unclear. In order to characterize mechanisms driving differences on energy metabolism of beef cattle skeletal muscle and liver tissue proteome was analyzed. From a group of 120 Nellore young bulls identified for RFI, cattle with the highest (n=9) and lowest (n=9) values were selected for protein abundance studies. Samples were collected immediately after slaughter and subjected to two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry to identify differentially abundant proteins associated with RFI values. Two differentially abundant spots were identified in skeletal muscle of high RFI group (Alpha actin 1 e 14-3-3 protein epsilon), one was identified in muscle of low RFI group (Heat shock protein beta-1) and one was identified in liver tissue of low RFI group (10-formyltetrahydrofolate dehydrogenase) (P<0.05). These data indicates that genetic selection for RFI tends to cause changes in skeletal muscle and liver protein profile, suggesting that differences in low and high RFI cattle may be due skeletal muscle protein turnover and liver energy metabolism.