The impact of viruses on our daily lives, from the common cold to COVID-19, is enormous, but infections that took place millions of years ago have had a profound impact on the course of human evolution. This is due to the incorporation of the viral genes into the host’s DNA, which has been passed down from generation to generation and has changed frequently as it has evolved.
Now, in a study published in Development, Dr. Fumitoshi Ishino, Professor of Molecular Biology at Tokyo Medical and Dental University, Japan, and Dr. Tomoko Kaneko-Ishino, Professor of Molecular Biology at Tokai University, Kanagawa , Japan, have discovered that two mouse genes, left behind by a viral infection millions of years ago, have evolved to help defend the brain against new infections.