OCT 08, 2018 10:48 AM PDT

Neanderthal DNA Helps us Fight Viruses

WRITTEN BY: Carmen Leitch

The last Neanderthals died around 40,000 years ago, but not before breeding with another species of human that was starting to move around the globe. As much as two percent of the genomes of some modern Asians and Europeans is Neanderthal DNA. Because some populations carry more of it than others, it’s been suggested that some of those Neanderthal genes may confer some advantage, but it may also have happened by chance. New research reported in Cell aims to settle that debate. Researchers at Stanford found the former - there is a benefit to carrying that DNA.

This is a skeleton of a Neanderthal (left) and a modern human (right). / Credit: Ian Tattersall

"Our research shows that a substantial number of frequently occurring Neanderthal DNA snippets were adaptive for a very cool reason," said Dmitri Petrov, an evolutionary biologist at Stanford's School of Humanities and Sciences. "Neanderthal genes likely gave us some protection against viruses that our ancestors encountered when they left Africa."

Neanderthals had not lived in Africa for hundreds of thousands of years by the time they met up with the other human species. They had adapted to the infectious diseases in Europe and Asia. Anyone just migrating into those areas would be at a disadvantage.

"It made much more sense for modern humans to just borrow the already adapted genetic defenses from Neanderthals rather than waiting for their own adaptive mutations to develop, which would have taken much more time," said David Enard, a former postdoctoral fellow in Petrov's lab.

Related: The Impact of Neanderthal DNA on Human Gene Expression

This work supports a model of gene-swapping between the species that has been called poison-antidote, noted Petrov and Enard. Neanderthals exposed the other species to diseases, but also provided genetic abilities to take the illnesses on successfully.

"Modern humans and Neanderthals are so closely related that it really wasn't much of a genetic barrier for these viruses to jump," said Enard, who now works as an assistant professor at the University of Arizona. "But that closeness also meant that Neanderthals could pass on protections against those viruses to us."

The researchers made a list of over 4,500 genes in modern humans, which interact with viruses. Enard compared the genes to Neanderthal DNA sequences, and 152 gene fragments from modern humans were found in the Neanderthal DNA. The defenses we humans inherited from Neanderthals are similar to RNA viruses, said the scientists. The 152 genes that contain Neanderthal fragments interact with influenza A, hepatitis C, and HIV, which are all RNA viruses. 

Only modern Europeans carry the Neanderthal genes the team identified, suggesting that other viruses or factors influenced gene swapping between Asians and Neanderthals. Because the interbreeding happened at different times, Enard suggested that this conclusion makes sense.

This work may help us learn more about ancient diseases as well, noted Enard. "It's similar to paleontology," he said. "You can find hints of dinosaurs in different ways. Sometimes you'll discover actual bones, but sometimes you find only footprints in fossilized mud. Our method is similarly indirect: Because we know which genes interact with which viruses, we can infer the types of viruses responsible for ancient disease outbreaks."

The video above from Vanderbilt University discusses how Neanderthal DNA has influenced our genome.

Sources: Phys.org via Stanford University - School of Humanities and Sciences, Cell

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
DEC 22, 2019
Genetics & Genomics
DEC 22, 2019
Functional Mini-Livers Made With New Bioprinting Technique
This technique, could be useful in the production of complete organs that can be transplanted into patients....
JAN 28, 2020
Cell & Molecular Biology
JAN 28, 2020
A Rare Genetic Disorder is Effectively Treated With Modified Stem Cells
A clinical trial used stem cell gene therapy to treat a rare genetic disorder called X-CGD. Image credit: UCLA Broad Stem Cell Research Center/Nature Medicine...
FEB 08, 2020
Microbiology
FEB 08, 2020
Novel Coronavirus Has Now Infected At Least 34,500 People
In China, authorities are still struggling to contain the new coronavirus that emerged in the city of Wuhan and has since spread around the globe....
FEB 10, 2020
Genetics & Genomics
FEB 10, 2020
The Broken Genes of the Last Woolly Mammoths
Wooly mammoths are thought to have died out around 4,000 years ago in a remote area off the Siberian coast, called Wrangel Island....
FEB 11, 2020
Neuroscience
FEB 11, 2020
Soybean oil Causes Genetic Changes in Mouse Brain
Source: Hypothalmus and limic system   Soybean oil is used for cooking fast food, in packaged products, and to feed livestock, making it the most wide...
FEB 27, 2020
Cell & Molecular Biology
FEB 27, 2020
Caloric Restriction Changes Gene Expression, Reduces Inflammation
New research has added to the evidence that suggests that dietary restriction has health benefits....
Loading Comments...