Sequence identity between the genomes of humans and viruses.

Lin, Gui-Gao; Li, Jin-Ming

OBJECTIVE People exposed to viruses usually do not develop diseases. Viruses cause diseases; however, most of the pathologic effects of these diseases are not caused directly by the viruses but by the side effects of the immune response. It is possible that sequence identity may exist between viruses and humans and may be biologically relevant to the infection of virus. The aim of this study was to find out whether sequence identity exists between viruses and humans. METHODS BLAST searches of virus genome sequences against human genome were performed using the resources of the National Center for Biotechnology Information (NCBI). RESULTS All the viruses that were compared to humans contain different numbers of short identical regions to the human genome. Each identical region was 20-30 nt and some were found at multiple sites within the human genome. CONCLUSION A new role of the virus in the relationship between viruses and humans was taken into account. We assume that viruses have brought their sequence into the human genome in the long past history of human-virus interaction. In the process, viruses play roles as carriers to transfer external sequence information into the human genome.