[Construction of an EB virus based shuttle vector plasmid pZH32].

The shuttle vector can replicate in both bacteria and eukaryotic cells. We have constructed a shuttle vector pZH32 based on the EB virus. Three component parts of the plasmid come from pSV2gpt, pS189 and pMCi5. An E. coli tyrosine suppressor tRNA gene, supF, was used as a mutagenic target in this plasmid, and a gpt gene was used as a selectable marker gene for transformed cells. This pZH32 based on EBV replicates autonomously in the nuclei of human cells. It has a low background mutation frequency. The plasmid can be used to examine the mutagenic mechanism of potential mutagens and carcinogens in mammalian cells.