Abstract：Serum albumin(alb) is the majority transport protein in serum, which mainly is synthesized by the liver. The objective of this study was to identify porcine serum albumin gene(alb) promoter region and its main regulation elements, to quest the alb gene’s expression and regulation mechanisms. Firstly, endogenous expression level of alb from different tissues of pig(Sus scorfa) and different cell lines of hepatic(hepa1-6) and porcine embryo fibroblkast (PEF) were analyzed by quantitative RT-PCR(qRT-PCR); Luciferase reporter vectors containing five different lengths of pig alb promoter region were constructed by cloning, DNA sequencing and other methods. Hepa1-6 and non hepatic PEF cell lines were transfected with these 5 vectors above-mentioned, then functions of different alb promoter region were validated through the observation of relative activities of luciferase reporter genes. Our results demonstrated that the pig alb gene showed a unique liver-specific expression pattern; the dual luciferase reporter assays revealed core region of alb promoter was located between -184 to -31 bp, deletion of this area would lead to loss of function. Between -184 ~ -2034 bp there existed some potential positive and/or negative regulatory elements involved in the regulation of pig alb gene expression. In this study five dual luciferase reporter vectors containing different fragments of Wuzhishan pig alb gene promoter were successfully constructed, core region of the promoter of the Wuzhishan pig alb gene were identified and the main regulatory elements within 2 kb upstream of the start codon were predicted. These studies may contribute to our understanding of the effective mechanisms of pig alb gene promoter, as well as construction of liver-specific expression vectors for further exogenous gene studies.
