abstract
- By making use of the fact that human adenovirus DNA circularizes in infected cells, and that circular forms of the viral genome are infectious, we have developed an improved adenovirus-based cloning system. A deletion mutant of adenovirus type 5 (Ad5) with deletions in early regions 1 (E1) and 3 (E3) was converted to a bacterial plasmid which can regenerate infectious virus following transfection into human 293 cells. A single XbaI recognition site in the deleted E3 region serves as a site for the insertion of foreign DNA. We have used this system to clone a number of genes into the Ad5 genome and describe the insertion of the neomycin/G418 resistance marker into Ad5 as an example.