G0S2 inhibits adipogenesis and unsaturated fatty acid biosynthesis by repressing the expression of SCD in chicken

Fatty acids metabolic products and intramuscular fat (IMF) content determine meat quality in chickens. In this study, the mechanisms of G0/G1 switch gene 2 (G0S2) underlying modulation of chicken IMF content as well as fatty acid synthesis was investigated. Several advanced techniques including Gas Chromatography-Mass Spectrometer (GC-MS), RNA-sequencing and lentiviral transfection were utilised. RNA-sequencing showed that 2242 differentially expressed genes were significantly different, and many of these were related to lipid catabolism, such as stearoyl-CoA desaturase 1 (SCD), acyl-CoA synthetase bubblegum family member 2 (ACSBG2), and fatty acid desaturase 2 (FADS2), etc. Knocking down of G0S2 also affected the biological activities of signal transduction, catalytic activity, lipid metabolism, cell cycle and death, cell differentiation and immune response. GC-MS revealed that decreased lipid accumulation and lower unsaturated fatty acid percentage were observed in G0S2 knockdown adipocytes. Our results showed that lower expression of G0S2 decreased lipid accumulation mainly via down-regulated SCD, then regulated mRNA levels of patatin-like phospholipase domain containing 2 (PNPLA2), which was shown as a major triglyceride lipase in the liver and adipose tissue. Importantly, we further verified the regulation network of G0S2 in the thigh tissues of 12 Huangshan Black chickens, which was consistent with previous IMF results. Thus, our study highlights that G0S2 modulated chicken meat quality traits by the G0S2-SCD-PNPLA2 axis in lipid metabolism in vitro and in vivo. These findings are expected to provide a strategy from a genetic perspective for improving the meat quality.