Effects of FABP1 gene interference on intramuscular fat deposition in pigs

【Objective】To clarify the effect of FABP1 gene on fatty acid and lipid synthesis in porcine intramuscular adipocytes and to provide a basis for further analysis of the regulatory role of FABP1gene on intramuscular fat deposition and lipid metabolism in pigs.【Method】Target sequences of FABP1 gene interference vector of Xiangsu crossed pigs were designed and synthesized, and then shRNA-FABP1 interference vector was constructed by vector ligation and validated by sequencing. The correct interfering target sequence was transfected into porcine intramuscular adipocytes, and the target sequence with the highest interference efficiency was screened by transfection effect and real-time fluorescence quantitative PCR(RT-qPCR) for next experiments. Total RNA from porcine intramuscular adipocytes transfected with shRNAFABP1 interference vector was extracted by the TRIzol^® Reagent total RNA extraction kit. RT-qPCR was used to detect the expression of genes related to fat deposition with cDNA being a template.Then the content of medium and long chain fatty acids(LCFA) in porcine intramuscular adipocytes was detected by targeted detection of gas chromatography-mass spectrometry(GC-MS), and the contents of triglycerides(TG) and cholesterol in porcine intramuscular adipocytes were detected by the GPO-PAP enzymatic method.【Result】The shRNA-FABP1 interference vector was successfully constructed and the fragment with the best interference efficiency was screened. FABP1 gene interference significantly(P<0.05, the same below) or extremely significantly(P<0.01, the same below) reduced the relative expression of fat deposition-related genes, including LPL, FABP3, IGFBP4 and OLR1. A total of 38 fatty acids were also detected in porcine intramuscular adipocytes with FABP1 gene interference, among which 29 had difference. FABP1 gene interference up-regulated the proportion of 17 fatty acids including methyl palmitate(C16: 0), stearic acid(C18: 0) and methyl oleate(C18: 1N9), and down-regulated the proportion of 12 fatty acids including eicosapentaenoic(C20:5N3), heptadecenoic acid(C17:1N7) and tridecanoic acid(C13:0). In addition, FABP1 gene interference significantly or extremely significantly reduced the contents of TG and cholesterol in intramuscular adipocytes of Xiangsu crossed pigs.【Conclusion】Interfering with the FABP1 gene alters the rate of fatty acid composition and reduces the contents of TG and cholesterol by inhibiting the expression of genes related to fatty acid transport and TG synthesis.