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 (eIFs) have been
reported to involve in muscle protein synthesis. We investigated the mRNA and protein expression levels of
eIF2B1, 4A1, 4B and 4E in Wujin 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 eIF2B1 mRNA and protein were increased by HP diet at all body weight. The HP diet showed
higher mRNA and protein levels of eIF4B gene at 60 and 100 kg. The protein expression of eIF4E 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 eIF2B1, 4B and 4E rather than 4A1 expression along the growth
stages.
Keywords dietary protein level, gene expression, translation initiation factor, swine
Correspondence S. Z. Gao and S. M. Zhao, Yunnan Key Laboratory of Animal Nutrition and Feed Science, Yunnan Agricultural University, Kunming,