Differentially Expressed Genes Analysis Of White Adipose Tissue During Fattening And Hibernation In Daurian Ground Squirrel(Spermophilus Dauricus)

In order to study the adaption and regulation mechanism of fat-storing hibernators in fattening progress and hibernation, we used the next transcriptome sequencing technology(RNA-Seq) to detect the transcriptome and anaylized the differentially expressed genes in the white adipose tissue of the Daurian ground squirrel(Spermophilus dauricus) at four physiological stages: Initial-Fattening,Rapid-Fattening, Finished-Fattening and Hibernation. The main results are as follows:1. Genes up-regulated including hexokinase, aldolase and enolase at Rapid-Fattening,which were favorable for animals to gain energy from carbohydrate; Genes encoding phosphoenolpyruvate carboxykinase, aldolase, citrate synthase and genes which played role in lipogenesis include acety-Co A carboxylase, fatty acid synthase, acyl-Co A desaturase 2 down-regulated at Finished-Fattening. At the same time, PDK4 highlighted significantly which supported the switch from carbohydrate to lipid catabolism. Expression levels of genes encoding enzymes involved in carbohydrate catabolism showed reduced at Hibernation and genes encoding acety-Co A carboxylase, fatty acid synthase and acyl-Co A desaturase 2also expressed at low levels. Genes expressed in high leve at Hibernation involved in carnitine palmitoyltransferase and PDK4, suggesting an increase in combustion of fat.2. Gene expression of leptin precursor had a few in Initial-Fattening and up-regulated in Rapid-Fattening and Finished-Fattening. It was suggested that high concentrations of leptin effected on regulating body weight in Finished-Fattening throughout inhibiting food intake. Leptin precursor continued expressing highly in Hibernation. It may be due to the tissue collected in Hibernation was shortly after they entered torpor. Gene of adiponectin expressed higher in Initial-Fattening and Rapid-Fattening than Finished-Fattening and Hibernation, it may contribute to carbohydrate intake.3. The genes of MHC Ⅱ, Ig H, Fc receptor and MHC Ⅰ expressed at low levels at three fattening stages and highlighted in Hibernation. It is suggested that immunity enhancement in WAT in Daurian ground squirrel during hibernation and high expression of genes may cause vasodilation and apoptosis. It would be conducive to energy molecule flow out of adipose tissue to provide energy for the hibernators.