Abstract
Porcine skeletal muscle fibres are classified based on their different physiological and biochemical properties. Muscle fibre phenotype is regulated by several independent signalling pathways, including the mitogen-activated protein kinase (MAPK), nuclear factor of activated T cells (NFAT), myocyte enhancer factor 2 (MEF2) and peroxisome proliferator-activated receptor (PPAR) signalling pathways. MicroRNAs are non-coding small RNAs that regulate many biological processes. However, their function in muscle fibre type regulation remains unclear. The aim of our study was to identify miRNAs that regulate muscle fibre type during porcine growth to help understand the miRNA regulation mechanism of fibre differentiation. We performed Solexa/Illumina deep sequencing for the microRNAome during 3 muscle growth stages (63, 98 and 161 d). In this study, 271 mature miRNAs and 243 pre-miRNAs were identified. We detected 472 novel miRNAs in the muscle samples. Among the mature miRNAs, there are 23 highest expression miRNAs (over 10000 RPM), account for 85.3% of the total counts of mature miRNAs., including 10 (43.5%) muscle-related miRNAs (ssc-miR-133a-3p, ssc-miR-486, ssc-miR-1, ssc-miR-143-3p, ssc-miR-30a-5p, ssc-miR-181a, ssc-miR-148a-3p, ssc-miR-92a, ssc-miR-21, ssc-miR-126-5p). Particularly, both ssc-miR-1 and ssc-miR-133 belong to the MyomiRs, which control muscle myosin content, myofibre identity and muscle performance. The involvement of these miRNAs in muscle fibre phenotype provides new insight into the mechanism of muscle fibre regulation underlying muscle development. Furthermore, we performed cell transfection experiment. Overexpression/inhibition of ssc-miR-143-3p in porcine skeletal muscle satellite cell induced an/a increase/reduction of the slow muscle fibre gene and protein (MYH7), indicating that miR-143 activity regulated muscle fibre differentiate in skeletal muscle. And it regulate MYH7 through the HDAC4-MEF2 pathway.
Highlights
Muscle fibre type is determined by the myosin structure or physiological capabilities of the muscle[1]
Fibres were classified into 3 types (1, 2a, and 2x+2b) using enzyme histochemical staining based on the acid stability of myosin ATPase and the glycolytic rate (Table 1)
To determine whether the apparent variation in these traits is caused by the differential expression of genes in the myosin heavy chain (MYH) genes family, which encoded proteins characteristic of different types of muscle fibre, we used RT-qPCR to assess the expression of MYH family at 63d, 98d and 161d
Summary
Muscle fibre type is determined by the myosin structure or physiological capabilities of the muscle[1]. The muscle fibre composition is an important factor influencing many of the peri- and postslaughter biochemical processes, influencing meat quality[2]. Our previous studies have indicated that meat colour, water holding capacity and meat pH are related to fibre composition. The regulation of fibre composition is a viable pathway for improving meat quality[3]. In postnatal porcine skeletal muscle, the number of muscle fibres is constant during growth. The type of muscle fibre can be regulated by various conditions, such as neuromuscular activity, mechanical loading, mechanical unloading, hormones, aging, and endurance exercise[5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
