This little Nature precis is food for thought, though I confess to not understanding two thirds of it (and to beginning to wonder just which part of me is doing the thinking). Essentially, it’s a discussion of the fact that we have genetic material which looks very much like the borna disease virus (BDV) embedded in our genome, probably a result of historical integration into the chromosome of germline cells. And here’s the little kicker at the end:
The fact that Horie and colleagues1 could readily detect BDV DNA and chromosomal insertions in human cells suggests that BDV retroposition might occur at an appreciable frequency during BDV infection, creating a source of mutation in infected individuals (Fig. 1b). This yields a tantalizing and testable hypothesis for the alleged, but still controversial, causative association of BDV infection with certain psychiatric disorders, such as schizophrenia and mood disorders2, 11. This possibility becomes even more intriguing when considering the recent demonstration of L1 hyperactivity in the human brain12, the primary site of BDV infection.