Full-Length CDNA Cloning And Expression Of Stearoyl-CoA Desaturase 1 (SCD1) Gene In The Liver Of Sichuan White Goose And Landes Goose Responding To Overfeeding

When overfeeding-induced lipogenesis exceeds the hepatic capacity for lipoprotein synthesis, a large proportion of the TG will be stored in the hepatocytes and may cause dramatic hepatic steatosis. Overfeeding carbohydrates to geese can result in the accumulation of TG in their liver cells, potentially leading to goose fatty liver formation. Monounsaturated fatty acids (oleic acid) are the most abundant fatty acids in the fatty liver. Stearoyl-CoA desaturase (SCD) is an endoplasmic reticulum enzyme that catalyzes the biosynthesis of monounsaturated fatty acids from saturated fatty acids and is the critical gene responsible for the synthesis of triglycerides, phospholipids and cholesterol esters. SCD1 plays an important role in triacylglycerol (TG) accumulation, as mice with a knockout of SCD1 showed impairment in TG accumulation, hepatic steatosis and plasma insulin levels. SCD1 plays an important role in feeding-induced adiposity and hepatic steatosis, Meanwhile, SCD1 may also play a role in VLDL-TG sretion. SCD1 deficiency dramatically reduced VLDL sretion in leptin-deficient ob/ob mice when VLDL hydrolysis was inhibited, suggesting that SCD1 deficiency may result in the impairment of VLDL-TG sretion.The EST sequence of goose (Anser cygnoides) Stearoyl-CoA desaturase 1 (SCD1) was obtained from a subtractive cDNA library. To further investigate the role of SCD1 in lipid metabolism in geese,5'-RACE and 3'-RACE were carried out in this study to obtain the complete cDNA sequence of goose SCD1. The results are as follows:(1) The complete cDNA sequence of goose SCD1, which contained a 29 bp 5'UTR, a 1074 bp open reading frame (ORF) encoding 357 amino acids, and a 125 bp 3'UTR.(2) BLAST analysis revealed that goose SCD1 shared high similarity with other known SCD1, especially, chicken (Gullas gullas) and bird (Taeniopygia guttata), their homology Up to 94%. (3) The deduced amino acid sequence of SCD1 consisted of four TMhelixs region and two Delta9-FADS-likes structure, In addition there are three histidine-box motifs and eight cysteines location.(4) The expression of SCD1 was measured in several tissues, The results of real time RT-PCR demonstrated that, compared to the brain, goose SCD1 mRNA was more abundant in the liver. the Second was sebum and abdominal fat, while almost no expression in other tissues.(5) Overfeeding markedly increased the mRNA expression of SCD1 gene in the liver of Sichuan White goose and Landes goose. In control group, the mRNA level of SCD1 in liver of Landes and Sichuan White goose is significant difference; compared with control group, In overfeeding group, the mRNA level of SCD1 in liver was marked higher of Sichuan White goose and Landes goose, however, there was not significant difference at the mRNA level of liver between the two breeds. The mRNA abundance of SCD1 in liver had significant positive correlations with the TG content in liver lipid, plasma insulin level and plasma very low density lipoproteins (VLDL) level in Landes geese and Sichuan White geese. and the correlation in Landes goose was stronger than that in Sichuan White goose.