Our DNA has evolved over hundreds of thousands of years. This evolution was usually the result of natural selection. Scientists have discovered another way our genetics have been altered: virus DNA. Our DNA consists of 100,000 pieces of viral DNA and altogether those pieces make up about 8 percent of our DNA. Most of these genes are from endogenous retrovirus. Many viral genes produce proteins that affect our health in unexpected ways. Some of our ancient virus DNA may be protecting us from diseases and others may be raising our risks for cancer.
Viral DNA is neither good nor bad. It’s not that simple and the research being done on this part of our genome is just being started. In a recent study scientists engineered healthy cells to make a viral protein that is found in tumors. They concluded that the protein caused the cells to behave in a “cancer like way”. There are other viral proteins that play a crucial role in reproduction, known as syncytins.
This caused scientists to investigate other viral proteins. Five years ago Dr. Heidmann, a French cancer researcher, found a stretch of viral DNA that has gone overlooked and named it Hemo. She also found that versions of this protein was in other species and that the gene behind is have barley changed over thousands of years. The consistency of the gene throughout species shows that the protein must play an important beneficial role. Some preliminary research has shown it to be involved with helping the embryo develop a variety of tissue from stem cells.
Many things are still not known about this part of our DNA and how it affects us but researchers are working hard to find out everything they can. They are actively trying to figure out which viral proteins are beneficial and which are harmful. This research will help us understand a lot about our genome, evolution, and maybe even cancer prevention.