RESUMO
The genetic analysis of herpesviruses has been a constant challenge, due to the large, complex genomes of herpesviruses and mutagenesis of viral genes by conventional recombination methods in cell culture. Recently, a completely new approach for full-length infectious clones of herpesviruses based on bacterial artificial chromosomes (BACs) has been developed. This technique allows the maintenance, propagation and genetic modification of the viral genome as a BAC plasmid in E.coli, thus making the procedures fast, safe and effective in prokaryotic cells. This technique also makes it possible for the reconstitution of viral progeny or mutants by transfection of the BAC plasmid into eukaryotic cells, thereby facilitating the analysis of viral gene functions in the context of genome. In this presentation, Epstein-Barr virus was used as an example to describe the principle, establishment of the technique and mutation introduction into the BAC plasmid, and to discuss the perspective in the use of BAC-cloned herpesviruses.