Recombinant herpesviruses as tools for the study of herpesvirus biology

This article is a brief summary of efforts to generate mutant herpesviruses for investigating and assigning gene functions of herpesviruses in replication and pathogenesis. While a full review of all herpesviruses is beyond the scope of this review, we focused our attention on the prototype of the herpesvirus subfamily - herpes simplex virus and murine gammaherpesvirus that serves as an excellent animal model to study human gammaherpesvirus pathogenesis. Furthermore, our present knowledge of essential, non-essential, and common genes of herpesviruses as well as of accessory genes that are currently being studied with the help of the bacterial artificial chromosome (BAC) system will also be discussed. This system facilitates the analysis of herpesviral genes with potential for use in gene therapy or as anti-cancer therapeutics.