A comparison of prenatal muscle transcriptome and proteome profiles between pigs with divergent growth phenotypes.

The growth of pigs is an important economic trait that involves multiple genes and coordinated regulatory mechanisms. The growth rate and potential of skeletal muscles are largely decided by embryonic myofiber development. Tibetan pig (TP) that is a mini-type breed has a divergent phenotype in growth rate and adult body weight with Wujin pig (WJ) and large White pig (LW). In the current study, the transcriptome (using RNA-seq) and proteome (using the isobaric tag for relative and absolute quantification [iTRAQ]) data from the prenatal muscle tissues were analyzed to identify the genes related to postnatal growth rate and growth potential in pigs. In the RNA-seq experiment, 19 626 genes were detected in the embryonic muscle tissues, and 3626 unique differentially expressed genes (DEGs) were identified in TP in comparison to that in LW and WJ. In the iTRAQ experiment, 2474 proteins were detected, and 735 unique differentially expressed proteins (DEPs) were identified in TP in comparison to that in LW and WJ. Combining the DEGs and DEPs, 209 genes were found to be differentially expressed, consistently at both the messenger RNA and protein levels, between TP and the other two breeds; these are mainly involved in 2-oxocarboxylic acid metabolism, citrate cycle, and biosynthesis of amino acids. Of these, 20 genes that were related to myoblast differentiation and muscle fiber formation might have important roles in determining the postnatal growth rate and potential body weight in pigs. Our results provide new candidate genes and insights into the molecular mechanisms involved muscle growth traits in pigs.