Molecular Evolution of Viruses - Past and Present

The studies in this special issue of VIRUS GENES provide information on the mechanisms by which viruses have evolved together with their natural hosts by acquiring RNA and DNA molecules from the infected cells into their genomes. Part A is devoted to studies on virus genes that were acquired to evade the vertebrate host immune system. Part B deals with the acquisition of cellular and foreign virus genes by Herpes and Irido viruses. The studies presented in Part C describe the poxvirus genes that are homologues of cellular genes. Together, these studies provide an insight into the evolutionary processes that viruses have developed to control the metabolic machinery of the infected tissue cells, and to prevent the defense machinery of the infected host, e.g., the immune system, from recognizing the infecting virus. Such mechanisms may explain the pathogenicity and reflect the virulence of viruses. §Molecular Evolution of Viruses - Past and Present: Evolution of Viruses by Acquisition of Cellular RNA and DNA was preceded by two VIRUS GENES special issues on the evolution of viruses ( VIRUS GENES 11:2/3, 1996, and VIRUS GENES 16:1, 1998). The first special issue dealt with the evolution of retrons, retroelements, retroviruses and endogenous retroviruses and current evolution of viruses. The second special issue provided information on the evolution of human, marine algae and fungal viruses. These issues, together with the third special issue on virus evolution, provide an interesting insight into the evolution of DNA and RNA viruses.