Comprehensive Gene Expression Analysis of Metabolic Pathways

For cDNA synthesis, 1000 ng of intact RNA was reversed to cDNA with a reverse transcription kit (YEASEN, Shanghai, China) with the concentration detected. The synthesized cDNA was diluted to 200 ng/μL as a template for RT-qPCR. To detect carbohydrate metabolism, the expression of genes related to glycogen synthesis (ugp2b, gys2), glycogen degradation (pygl), gluconeogenesis (pck1, pcxb), glycolysis (gck), TCA cycle pathway (idh), and pentose phosphate pathway (g6pd) were evaluated. The expression of genes related to lipid synthesis (fasn, acaca, aclyb) and decomposition (acadl, acaa1, lpl) were determined to illustrate the influence on lipid metabolism, and the expression of genes related to the urea cycle (gs, cps3, otc, ass, asl, and arg1) was also detected. The qPCR was performed in Jena qTOWER3G system using the real-time quantitative PCR detection kit EvaGreen 2 × qPCR Master mix (YEASEN, Shanghai, China): pre-denaturation at 95 °C for 5 min; denaturation at 95 °C for 10 s; annealing and extension at 60 °C for 30 s; and PCR reaction step running 40 cycles. After RT-qPCR, melting curves were analyzed to ensure the specificity of the reaction. Using 18s as the internal reference gene, the relative quantitative data analysis was performed by the 2^−ΔΔCt method. RT-qPCR data were analyzed using GraphPad Prism 6. The primers used in the present study are shown in Table 1.