Over the course of evolution, several groups of ancient viruses colonized our ancestors’ genomes, leaving thousands of fragments of viral code in modern-day human DNA. The bulk of HERVs integrated during primate evolution. Subsequent mutations in these sequences have rendered older insertions nonfunctional, but some of the younger and more intact sequences from HERVs have been linked to disease.
Around 8 percent of our genetic code stems from HERVs, the bulk of which integrated during primate evolution.
Current research suggests that viral hitchhikers in human DNA may play roles in cancer, inflammation, and neurodegenerative disorders. The mechanisms that underpin these connections between human endogenous retroviruses (HERVs) and disease are just beginning to emerge. Transcription of viral RNA can signal the presence of foreign DNA in cells, triggering defensive immune reactions. Scientists have also proposed that synthesis of the HERV envelope protein—which once enclosed the viral capsid of its retroviral ancestors—exerts ...
