Abstract：Promoter is a key cis-acting element to regulate gene expression, which is also an important element of the expression vector in genetic engineering. Understanding the structure and function of promoters contributes to constructing vector and controlling the gene expression, further we can achieve the goal that induces protein expression selectively. Therefore introducing a proper method to clone the promoter presents significance and wide application prospects. Since the invention of polymerase chain reaction (PCR) technique, several PCR-based chromosome walking methods have been developed to amplify unknown promoter sequences flanked by a known segment. In this review, we introduce the PCR-based methodologies for the rapid acquisition of unknown promoter, including Inverse PCR, Ligation-mediated PCR, Semi-random primer PCR. These principles and research progresses of each approach are discussed.
