Profiling of skeletal muscle tissue for long non-coding RNAs related to muscle metabolism in the QingYu pig at the growth inflection point

OBJECTIVE: Investigation of muscle growth at different developmental stages is an appropriate strategy for studying the mechanisms underlying muscle development and differences in phenotypes. In particular, the muscle development mechanisms and the difference between the fastest and slowest growth rates. METHODS: In this study, we used a growth curve model to fit the growth inflection point (IP) of QingYu pigs and compared differences in the long non-coding RNA (lncRNA) transcriptome of muscle both at the growth IP and plateau phase (PP). RESULTS: The growth curve of the QingYu pig had a good fit (R(2) = 0.974) relative to a typical S-curve and reached the IP at day 177.96. At the PP, marbling, intramuscular fat, and monounsaturated fatty acids had increased significantly and the percentage of lean muscle and polyunsaturated fatty acids had decreased. A total of 1,199 mRNAs and 62 lncRNAs were differentially expressed at the IP compared with the PP. Additional to gene ontology and Kyoto encyclopedia of genes and genomes pathway analyses, these differentially expressed protein coding genes were principally related to muscle growth and lipid metabolism. CONCLUSION: Our results suggest that the identified differentially expressed lncRNAs, could play roles in muscle growth, fat deposition and regulation of fatty acid composition at the IP and PP.