The admid system: Generation of recombinant adenoviruses by Tn7-mediated transposition in E-coli

A new system has been developed for generating recombinant adenoviruses by Tn7-mediated transposition in E. coli. Low copy number E. coli plasmids con taining a full-length adenoviral genome with lacZatt-Tn7 replacing EI have been constructed The adenovirus plasmid or admid, as well as high copy numb er progenitors, were stably maintained in E. coli strain DH10B. Several tra nsfer vectors containing a mammalian expression cassette flanked by Tn7R an d Tn7L were used as donors to transpose the mini-Tn7 into the EI region of the adenoviral genome. Transposed recombinant admids are readily identified by their beta-galactosidase phenotype. Transfection of admid DNA into prod ucer cells resulted in the efficient production of infectious adenovirus. T his easy-to-use, efficient system generates pure, clonal stocks of recombin ant adenovirus without successive rounds of plaque purification.