JUL 21, 2016 05:18 PM PDT

Viruses are a Powerful Force Driving Evolution in Mammals

WRITTEN BY: Carmen Leitch

OOPS! THAT EXPERIMENT FAILED...

It's not your fault! Something went wrong with our formula.
Please begin your experiment again by clicking here.

If this error continues to occur please contact us at support@labroots.com.

Publishing in eLife, researchers at Stanford University have begun to reveal the extent of the influence viruses have had on mammalian evolution. In the study, computational genomic technology was used to find that viruses were the driving force behind 30 percent of all changes to proteins since humans diverged from chimpanzees, and they remarked that this is a conservative estimate.
Aminopeptidase N is a protein that acts as a receptor for coronaviruses, the family of viruses behind recent epidemics of SARS and MERS, among others. / Credit: Image Courtesy of David Enard
Mammals evolve in response to changes in their environments, and do so through random mutations in their DNA. Through serendipity, some of those are beneficial, making an animal a better match to those environmental changes; they are called adaptive mutations.

In the last decade, biologists studying evolution have found lots of adaptive mutations in many locations in mammalian genomes. It led investigators to wonder what could be causing those ubiquitous changes. Because of their pervasive and adaptable nature, and their ability to interact with the genome, viruses have been ideal candidates.

"When you have a pandemic or an epidemic at some point in evolution, the population that is targeted by the virus either adapts, or goes extinct. We knew that, but what really surprised us is the strength and clarity of the pattern we found," explained David Enard, first author of the study and a postdoctoral fellow at Stanford University. "This is the first time that viruses have been shown to have such a strong impact on adaptation."

The work had to begin with finding out what proteins physically interact with viruses. Previous work in the area has focused primarily on proteins of that are part of the body’s immune response, which is to be expected. The team had to carefully examine tens of thousands of research abstracts to develop a list of 1300 potential proteins as participants in a viral interaction. 

"The big advancement here is that it's not only very specialized immune proteins that adapt against viruses," commented Enard. "Pretty much any type of protein that comes into contact with viruses can participate in the adaptation against viruses. It turns out that there is at least as much adaptation outside of the immune response as within it."
Patterns of adaptation to coronaviruses in Aminopeptidase N. This protein has repeatedly adapted during mammalian evolution to evade binding by coronaviruses. (A) BS-REL test results for ANPEP in a tree of 84 mammalian species. (B) Contact surface with PRCV and TGEV on ANPEP structure (PDB 4FYQ). The figure includes visualizations of all the six different faces of ANPEP. / Credit: Image Courtesy of David Enard
Next, algorithms were created to search genomic databases to compare how virus-interacting proteins evolved versus other proteins. The team found that changes occurred three times as much in proteins that interacted with viruses compared with proteins that did not.

"We're all interested in how it is that we and other organisms have evolved, and in the pressures that made us what we are," said lead author Dmitri Petrov, a Professor of Biology and Associate Chair of the Biology Department at Stanford. "The discovery that this constant battle with viruses has shaped us in every aspect -- not just the few proteins that fight infections, but everything -- is profound. All organisms have been living with viruses for billions of years; this work shows that those interactions have affected every part of the cell."

Viruses multiply and disseminate by taking over a host’s cells, so it’s not surprising that they have an even greater influence on cellular changes than environmental conditions or competition from other species. The researchers suggest that these findings could be an explanation for why similar species have different mechanisms for the same biological functions. "This paper is the first with data that is large enough and clean enough to explain a lot of these puzzles in one fell swoop," said Petrov.

The scientists now plan to research viral epidemics of the past, in the hopes they’ll find clues for fighting current diseases. 

Sources: eLife, Science Daily via Genetics Society of America
About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAY 30, 2018
Microbiology
MAY 30, 2018
'Innoculating' Newborns with Vaginal Fluids Found to be Unsafe
A lack of exposure to the vaginal canal does not account for the increased risk of later health problems for those born by C-section, researchers say....
JUN 06, 2018
Microbiology
JUN 06, 2018
Beating Stress with Bacteria
Microbes might be useful in the treatment of mental disorders like anxiety, depression and PTSD....
JUN 23, 2018
Microbiology
JUN 23, 2018
In a First, Keystone Virus Sickens a Person
A teenage boy in North Central Florida presented with symptoms that defied diagnosis....
JUN 29, 2018
Microbiology
JUN 29, 2018
Finding a Way to End a Persistent Cholera Epidemic
Tracing back to Indonesia, 1961, the current outbreak has been going on for over fifty years....
JUL 12, 2018
Microbiology
JUL 12, 2018
The World's Oldest Colors
In this work, the importance of algae to complex food chains was highlighted....
AUG 02, 2018
Genetics & Genomics
AUG 02, 2018
The Genetic Hotspots That Can Lead to Cancer
In some of our body's tissues, cells have to replicate many times. That introduces a chance for new genetic errors every time....
Loading Comments...