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
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
Remarkable Results From First Gene Therapy for Glycogen Storage Disease
A one-year clinical trial of a new gene therapy has produced surprisingly good results for several patients....
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
We Already Have the Ingredients for the Next Food Revolution
The third agricultural revolution changed the way millions of people lived in the 1950s and 60s. It's now time for another one....
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
Mutants Are Everywhere - You're One Too
As fathers age, they tend ot pass down more genetic mutations to their children....
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
Dolphins Lost 85 Genes to Become Aquatic
Dolphins, whales and porpoises are marine mammals; otherwise known as cetaceans. Although they live exclusively underwater nowadays, tens of millions of ye...
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
Antibiotic-Resistance Genes Can Move From Humans to Animals
Researchers at Clemson University have been investigating how antibiotic resistance can move from humans into animals....
NOV 15, 2019
Genetics & Genomics
NOV 15, 2019
A 'Molecular Clock' for Determining a Child's Age
This tool can aid in the diagnosis of developmental disorders, including autism spectrum disorder....
Loading Comments...