Most of our viral DNA comes from one group in particular: retroviruses, a group that includes HIV. These viral genes co-opt the cell’s machinery, using it to make new viruses that escape to infect more cells. But over the generations, the viral DNA mutates, and endogenous retroviruses eventually lose the ability to infect new cells. After a single infection, an endogenous retrovirus may build up hundreds of copies of itself in its host’s DNA. But John M. Coffin, a virologist at Tufts University, suspects there’s less to these viral proteins than meets the eyes.

Source: New York Times October 04, 2017 16:46 UTC