Poxvirus homologues of cellular genes

Over the course of time poxviruses have acquired or "captured" numerous hom ologues of cellular genes and incorporated them into their large DNA genome s. With more poxvirus genome sequencing data becoming available, the number of newly discovered poxviral cellular homologues is constantly increasing. A common feature of these genes is that they are nonessential for virus re plication in vitro and they confer selective advantages in dealing with hos t cell differentiation and immune defense mechanisms in vivo. Poxviral cell ular homologues are reviewed in this synopsis considering the specific vira l habitats of different poxviruses and the immune defence capabilities of t heir respective hosts. Possible mechanisms of cellular gene acquisition by poxviruses as suggested by the analysis of mobile genetic elements in large DNA viruses are discussed. The investigation of poxvirus homologues of cel lular genes is essential for our understanding of the mechanisms that regul ate virus/host interactions on the cellular level and the host response aga inst infection.