Proteomic analysis indicates that mitochondrial energy metabolism in skeletal muscle tissue is negatively correlated with feed efficiency in pigs

Liangliang Fu,Xiaolong Qi,Shuhong Zhao,Huazhen Liu,Yu Luan,Lu Jing,Xinyun Li,Ye Hou,Yuanxin Miao,Huiying Liu,Yueyuan Xu,Lian Zhou

doi:10.1038/srep45291

Abstract

Feed efficiency (FE) is a highly important economic trait in pig production. Investigating the molecular mechanisms of FE is essential for trait improvement. In this study, the skeletal muscle proteome of high-FE and low-FE pigs were investigated by the iTRAQ approach. A total of 1780 proteins were identified, among which 124 proteins were differentially expressed between the high- and low-FE pigs, with 74 up-regulated and 50 down-regulated in the high-FE pigs. Ten randomly selected differentially expressed proteins (DEPs) were validated by Western blotting and quantitative PCR (qPCR). Gene ontology (GO) analysis showed that all the 25 DEPs located in mitochondria were down-regulated in the high-FE pigs. Furthermore, the glucose-pyruvate-tricarboxylic acid (TCA)-oxidative phosphorylation energy metabolism signaling pathway was found to differ between high- and low-FE pigs. The key enzymes involved in the conversion of glucose to pyruvate were up-regulated in the high-FE pigs. Thus, our results suggested mitochondrial energy metabolism in the skeletal muscle tissue was negatively correlated with FE in pigs, and glucose utilization to generate ATP was more efficient in the skeletal muscle tissue of high-FE pigs. This study offered new targets and pathways for improvement of FE in pigs.

Highlights

The molecular mechanisms of the feed efficiency (FE) trait have been partially revealed by transcriptome analysis
The differentially expressed proteins (DEPs) and important signaling pathways related to the FE trait have been identified
We observe that all the DEPs located at the mitochondria are significantly down-regulated in the high-FE pigs

Summary

Introduction

The molecular mechanisms of the FE trait have been partially revealed by transcriptome analysis. Transcriptome analysis has shown that the signaling pathway of ESR1 could affect the FE trait by regulating acute caloric restriction of pigs[17]. Our recent study showed that the signaling pathway of vitamin A metabolism in liver tissue is related to FE in pigs[18]. In skeletal muscle tissues, the signaling pathways of muscle growth and mitochondrial energy metabolism were found to be related to FE in pigs. The expression levels of five key energy metabolism genes, namely, FABP3, RCAN, PGC-1A, HK2, and PRKAG2, in skeletal muscle tissues were negatively related to FE in pigs[19]. We systematically analyzed the differentially expressed proteins (DEPs) in the skeletal muscle tissues of high- and low-FE pigs using the iTRAQ approach. Functional analysis revealed that mitochondrial energy metabolism and cytoplasm glucose metabolism are closely related to FE in pigs

Methods

Results

Conclusion