In a new study, published in the eLife scientific review, researchers describe the application of large data analyzes to reveal the full extent of influencing viruses in human and other mammalian development. The findings of the study show that 30 percent of all protein adjustments since the time of humans deviating from the chimpanzees have been driven by the viruses.
When an environmental change occurs, species are able to adapt to change due to mutations in their DNA. Although these mutations occur accidentally, some of them make the body better adapted to its new environment. These are known as adaptive mutations.
Over the last decade, scientists have discovered a large number of adaptive mutations in a wide variety of locations in the genome of humans and other mammals. The fact that adaptive mutations are so diffused is a mystery. What kind of environmental pressure could potentially lead to so much adaptation to so many points of the genome?
Viruses are ideal candidates as they are always present, constantly changing and interacting with hundreds of thousands of proteins.
“When we have a pandemic or epidemic at some point in the evolution, the population targeted by the virus either adapts or disappears,” the researchers said in their study. “We knew this, but what really surprised us is the power and clarity of the pattern we found.”
Previous studies on interactions between viruses and proteins have focused on individual proteins that are directly involved in the immune response.
This is the first study that takes a global look at all kinds of proteins. “The great progress here is that they are not just very specialized immune proteins that are anti-viral, but pretty much any kind of protein that comes in contact with viruses can be involved in antiviral adaptation. It turns out that there is at least as much adaptation outside and within the immune response, “the researchers also state in their study.
The first step in the group was to identify all proteins that are known to interact naturally with viruses. After analyzing tens of thousands of scientific publications, they came up with a list of 1,256 proteins. The next step was to construct large data algorithms to define genomic databases and compare the evolution of proteins that interact with viruses with that of other proteins.
The results of their analysis revealed that adaptations have occurred three times more frequently in proteins that interact with viruses than other proteins. This discovery that this battle with viruses has shaped us in all respects is profound.
All organisms have been living with viruses for billions of years. The new study shows that these interactions have affected every part of the cells. Viruses eclipse almost every function of the cells of an organism host in order to reproduce and spread them, so it makes sense to drive the evolution of the cellular mechanism to a greater extent than other evolutionary pressures such as predation or environmental conditions.
The study also sheds light on some long-term biological mysteries, as closely related species have evolved different mechanisms that perform identical cellular functions, such as DNA replication or membrane production.