Abstract :
For the past two decades virologists have strived to make full-length clones of viral genomes that, on transfection into permissive eukaryotic cells, initiate a productive infection. The large variety of viral RNA and DNA genome structures, as well as different replication strategies, has required investigators to develop new approaches to produce infectious DNA in Escherichia coli. A member of the poxviridae, one of the most complex virus families, has now been made into an infectious clone in E. coli for the first time. Although the isolation was complicated, the infectious clone will greatly simplify future genetic studies of the virus.