The effect of dietary protein levels on the expression of genes coding for four selected protein translation initiation factors in muscle tissue of W ujin pig

Summary The objective of this study was to investigate the regulatory mechanism underlying the increased muscle protein accumulation in pigs while were fed a high protein diet. The eukaryotic initiation factors (e IF s) have been reported to involve in muscle protein synthesis. We investigated the m RNA and protein expression levels of e IF 2 B 1, 4 A 1, 4 B and 4 E in W ujin pigs fed either a high protein ( HP : 18%) or a low protein ( LP : 14%) diet at 30, 60 or 100 kg body weight, based on real‐time PCR and western blotting analyses. Our results indicated that the expression levels of e IF 2 B 1 m RNA and protein were increased by HP diet at all body weight. The HP diet showed higher m RNA and protein levels of e IF 4 B gene at 60 and 100 kg. The protein expression of e IF 4 E phosphorylation was increased by HP diet only at 30 kg. These data suggested that the HP diet promoted porcine muscle protein accumulation mainly by up‐regulating e IF 2 B 1, 4 B and 4 E rather than 4 A 1 expression along the growth stages.