The evolution of large DNA viruses: combining genomic information of viruses and their hosts

Research describing the patterns and processes of evolution in large DNA viruses has been hampered by low levels of sequence similarity between virus families and the absence of a viral fossil record. By analysing patterns of genome organization, the similarities among host and viral genes, and virus and host phylogenies it is now possible to show that DNA viruses have undergone intergenomic lateral gene transfer and intragenomic gene duplication during their evolution. Many viral proteins are also homologous to cellular proteins, suggesting extensive host gene capture. This new, combined approach to studying viral evolution enhances our ability to infer the origins of virus and host genes as well as the complex evolutionary history of large DNA viruses.