Eukaryotic expression vector containing attenuated SV40 promoter/dihydrofolate reductase expression element, and construction method thereof

The invention provides a eukaryotic expression vector capable of selecting high expression clones conveniently and high efficiently. The eukaryotic expression vector is obtained via structure modification by taking pBudCE4.1 carrier as a basic carrier; peptide chain elongation factor gene promoter (P ) on the basic carrier, and multiple cloning sites on the downstream of the peptide chain elongation factor gene promoter (P ) are replaced by an expression element composed of attenuated SV40 promoter and dihydrofolate reductase gene on the downstream of the attenuated SV40 promoter; multiple cloning sites on the downstream of cytomegalovirus early promoter (P ) of the basic carrier are replaced by new multiple cloning sites.