The myostatin (MSTN) gene is of interest in the livestock industry because mutations in this gene are closely related to growth performance and muscle differentiation. Thus, in this study, we established MSTN knockout (KO) quail myoblasts (QM7) and investigated the regulatory pathway of the myogenic differentiation process. We used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 to generate MSTN KO QM7 cells and subsequently isolated a single cell-derived MSTN KO QM7 subline with 10- and 16-nucleotide deletions that induced translational frameshift mutations. The differentiation capacity and proliferation rate of MSTN KO QM7 cells were enhanced. We conducted next-generation-sequencing (NGS) analysis to compare the global gene expression profiles of wild-type (WT) QM7 and MSTN KO QM7 cells. Intriguingly, NGS expression profiles showed different expression patterns of p21 and p53 in MSTN KO QM7 cells. Moreover, we identified downregulated expression patterns of leukemia inhibitory factor and DNA Damage Inducible Transcript 4, which are genes in the p53 signaling pathway. Using quantitative RT-PCR (qRT-PCR) analysis and western blotting, we concluded that p53-related genes promote the cell cycle by upregulating p21 and enhancing muscle differentiation in MSTN KO QM7 cells. These results could be applied to improve economic traits in commercial poultry by regulating MSTN-related networks.
Keywords: MSTN knockout; Muscle differentiation; Quail; p53 signaling pathway.