Novel eukaryotic expression vectors which permit single-stranded replication in Escherichia coli and in vitro translational analysis of cloned genes.

The ability to express cloned genes transiently is an important technique in the study of eukaryotic gene expression. Numerous useful expression vectors have been constructed for this purpose although many of them share several common drawbacks. In this paper I describe the construction and characterization of novel expression vectors pSVKII and pSVKIII which have 13 and 8 unique restriction sites, respectively, suitable for cloning genes. These vectors have phage M13 ori, which permits them to produce and package ss DNA molecules in Escherichia coli host, thus facilitating the sequencing and site directed mutagenesis of a cloned gene. Expression vector pSVKIII has a T7 phage promoter located between the SV40 promoter and the multiple cloning sites, which permits efficient transcription and in vitro translation of the cloned gene prior to in vivo studies.