The regulation of skeletal muscle growth and development in chicken is complex.
MicroRNAs (
miRNAs) have been found to play an important role in the process, and more research is needed to further understand the regulatory mechanism of
miRNAs. In this study, leg muscles of Jinghai yellow chickens at 300 d with low
body weight (slow-growing group) and high
body weight (fast-growing group) were collected for
miRNA sequencing (
miRNA-seq) and Bioinformatics analysis revealed 12 differentially expressed
miRNAs (DEMs) between the two groups. We predicted 150 target genes for the DEMs, and GO and KEGG pathway analysis showed the target genes of miR-24-3p and novel_miR_133 were most enriched in the terms related to growth and development. Moreover, networks of DEMs and target genes showed that miR-24-3p and novel_miR_133 were the 2 core
miRNAs. Hence, miR-24-3p was selected for further functional exploration in chicken primary myoblasts (
CPMs) with molecular biology technologies including qPCR, cell counting kit-8 (CCK-8),
5-ethynyl-2'-deoxyuridine (EdU) and immunofluorescence. When proliferating
CPMs were transfected with miR-24-3p mimic, the expression of
cyclin dependent kinase inhibitor 1A (P21) was up-regulated and both
CCK-8 and EdU assays showed that the proliferation of
CPMs was inhibited. However, when the inhibitor was transfected into the proliferating
CPMs, the opposite results were found. In differentiated
CPMs, transfection with miR-24-3p mimic resulted in up regulation of MYOD, MYOG and MYHC after 48 h. Myotube areas also increased significantly compared to the mimic negative control (NC) group. When treated with inhibitor, differentiation
CPMs produced the opposite effects. Overall, we revealed 2
miRNAs (novel_miR_133 and miR-24-3p) significantly related with growth and development and further proved that miR-24-3p could suppress the proliferation and promote differentiation of
CPMs. The results would facilitate understanding the effects of
miRNAs on the growth and development of chickens at the post-transcriptional level and could also have an important guiding role in yellow-feathered chicken breeding.