Deciphering the miRNA transcriptome of Rongchang pig longissimus dorsi at weaning and slaughter time points.

MicroRNA (miRNA) is essential for the process of gene posttranscriptional regulation in skeletal muscle of many species, such as mice, cattle and so on. However, a little number of miRNAs have been reported in the muscle development of Chinese native pig breeds. In this study, the longissimus dorsi transcripts of Chinese native Rongchang pig at weaning and slaughter time points were analysed for miRNA-seq. The results showed that 19 novel and 186 known miRNAs involved in the Rongchang pig skeletal muscle development were identified. Based on these findings, we further confirmed that porcine miR-127, miR-299 and miR-432-5p were obviously down-expressed in adult pig (287 days of age), while miR-7134-3p and 664-5p were significantly up-expressed in weaning pig (35 days of age). In other words, these miRNAs could be the potential molecular markers and play vital roles in the muscle development process. Moreover, we found miR-127 could inhibit the proliferation and myogenesis of porcine satellite cells in longissimus dorsi muscle. Our findings will provide deep insight into miRNA function for pork quality research with Chinese indigenous pig breeds.