An integrated analysis revealed different microRNA-mRNA profiles during skeletal muscle development between Landrace and Lantang pigs.

Pigs supply vital dietary proteins for human consumption, and their economic value depends largely on muscle production. MicroRNAs are known to play important roles in skeletal muscle development. However, their relationship to distinct muscle production between pig breeds remains unknown. Here, we performed an integrated analysis of microRNA-mRNA expression profiles for Landrace (LR, lean) pigs and the Chinese indigenous Lantang pig (LT, lard-type) during 8 stages of skeletal muscle developmental, including at 35, 49, 63, 77 dpc (days post coitum) and 2, 28, 90, 180 dpn (days postnatal). As differentially expressed-miRNA expression profiles can be well classified into two clusters by PCA analysis, we grouped the embryonic stages as G1 and the postnatal stages as G2. A total of 203 genes were predicted miRNA targets, and a STEM analysis showed distinct expression patterns between G1 and G2 in both breeds based on their transcriptomic data. Furthermore, a STRING analysis predicted interactions between 22 genes and 35 miRNAs, including some crucial myogenic factors and myofibrillar genes. Thus, it can be reasonably speculated that myogenic miRNAs may regulate myofibrillar genes in myofiber formation during embryonic stages and muscle hypertrophy during postnatal stages, leading to distinct differences in muscle production between breeds.