Comparison of the transient late region expression of SV40 DNA and SV40-based shuttle vectors: development of a new shuttle vector that is efficiently expressed.

Transient expression of an SV40-based shuttle vector similar in design to commonly used vectors is shown to be inefficient when compared to expression of SV40 viral DNA. To eliminate this problem, we have designed and constructed a new vector, pSVPiC, which contains a minimal noninterfering plasmid component, the 885-bp plasmid PiAN7, and two SV40 promoter/origin regions. Transient expression of the SV40 late region from pSVPiC is much more efficient than that from previously used vectors and even more efficient than that from SV40 viral DNA. When the gene for rabbit beta-globin is placed in the late region of pSVPiC, it is also expressed at high levels, indicating that this shuttle vector is generally useful for expressing eukaryotic genes.