Differential miRNA expression profiles in the longissimus dorsi muscle between intact and castrated male pigs

• We examined the role of miRNAs in skeletal muscle growth in castrated male pigs.
• MiRNA expression profiles in skeletal muscle were significantly altered by castration.
• Differentially expressed miRNAs are involved in skeletal muscle contractile function.
• Differentially expressed miRNAs are involved in skeletal muscle fat metabolism.

MicroRNAs (miRNAs) are important modulators of skeletal muscle development in multiple mammalian species, but their role in skeletal muscle growth in castrated male pigs has not been well studied. The aim of the present study was to determine the role of miRNAs in longissimus dorsi muscle under castration. Our results showed that castration caused a significant decrease in serum testosterone levels as well as carcass lean mass, but led to an increase in carcass fat mass. Moreover, miRNA expression profiles in skeletal muscle were significantly altered by castration, and seven differentially expressed miRNAs were discovered. More importantly, functional analysis suggested that these differentially expressed miRNAs and their targets are involved in the regulation of skeletal muscle contractile function and fat metabolism. Taken together, these results demonstrate altered miRNA expression in skeletal muscle of castrated male pigs, and suggest a potential mechanism underlying the effects of castration on porcine skeletal muscle growth.