Use of BK vius DNA as a vector for eukaryotic genes in human cells stablytransformed to TK+ phenotype [Uso del DNA del virus BK come vettore di geni eucariotici in cellule umane trasformate stabilmente al fenotipo TK+]

We describe a novel expression vector, pML-BK-TK, that persists episomally in human cells. This vector includes sequences from plasmid pML, BK virus and the thymidine kinase gene of herpes simplex virus type 1. pML-BK-TK transforms human TK- cells to the TK+ phenotype, producing stable clones. The transformed cells contain 30 to 100 vector copies per cell. With recombinant cells contain 30 to 100 vector copies per cell. With recombinant DNA recovered by the Hirt technique from transformed clones, we transformed E. coli strains and found molecules not rearranged indistinguishable from the input vector.