Knockdown of the myostatin gene by RNA interference in caprine fibroblast cells

Myostatin (MSTN), a member of transforming growth factor-beta superfamily is a negative regulator of the skeletal muscle growth. It suppresses the proliferation and differentiation of myoblast cells. Dysfunction of MSTN gene either by natural mutation or induced through genetic manipulation (knockout or knockdown) has been reported to increase the muscle mass in mammalian species. RNA interference (RNAi) is the most promising method for inhibition of gene expression that can be utilized for MSTN gene knockdown by developing short hairpin RNA (shRNA) construct against it. In the present investigation silencing of MSTN gene in caprine fibroblast cell line was evaluated using four different shRNA expressing constructs. Variation in the efficiency of silencing (22-92%) was obtained among different constructs. It was observed that sh1 and sh4 constructs downregulated the MSTN gene expression by reducing 92.4 and 80.5% (P<0.05) level of downregulation MSTN mRNA, respectively. On the contrary, the sh3 construct significantly upregulated the MSTN mRNA level (P<0.05). These two promising constructs (sh1 and sh4) need to be further tested for interferon (IFN) response before their use in long term stable expression of anti-MSTN shRNA in muscle cells to improve chevon production.