Hints of an Ancient Coronavirus Outbreak Appear in Modern East Asian DNA.

 Kelly Baclija

Mr. Ippolito

AP Bio

April 16, 2021

Bower, Bruce. “Hints of an Ancient Coronavirus Outbreak Appear in Modern East Asian DNA.” Science News, 14 Apr. 2021, www.sciencenews.org/article/ancient-coronavirus-epidemic-east-asia-dna-covid.

An ancient coronavirus, or a closely related pathogen, triggered an epidemic among ancestors of present-day East Asians roughly 25,000 years ago, a new study indicates. Analysis of DNA from more than 2,000 people shows that genetic changes in response to that persistent epidemic accumulated over the next 20,000 years or so, David Enard, an evolutionary geneticist at the University of Arizona in Tucson, reported April 8 at the virtual annual meeting of the American Association of Physical Anthropologists. Enard’s group consulted a publicly available DNA database of 2,504 individuals from 26 ethnic populations on five continents, including Chinese Dai, Vietnamese Kinh and African Yoruba people. The team first focused on 420 proteins known to interact with coronaviruses, including 332 that interact with SARS-CoV-2, the virus that causes COVID-19. These interactions could range from boosting immune responses to making it easier for a virus to hijack a cell. Substantially increased production of all 420 proteins, a sign of past exposures to coronavirus-like epidemics, appeared only in East Asians. Enard’s group traced the viral responses of 42 of those proteins back to roughly 25,000 years ago. An analysis of the genes known to orchestrate production of those proteins determined that specific variants became more common around 25,000 years ago before leveling off in frequency by around 5,000 years ago. That pattern is consistent with an initially vigorous genetic response to a virus that waned over time, either as East Asians adapted to the virus or as the virus lost its ability to cause disease, Enard said. Twenty-one of the 42 gene variants act either to enhance or deter the effects of a wide array of viruses, not just coronaviruses, suggesting that an unknown virus that happened to exploit similar proteins as coronaviruses could have instigated the ancient epidemic, Enard said.

These findings are important because they raise the possibility that some East Asians today have inherited biological adaptations to coronaviruses or closely related viruses and ultimately helps us learn more about the current pandemic. This discovery opens the way to exploring how genes linked to ancient viral epidemics may contribute to modern disease outbreaks, such as the COVID-19 pandemic. Genes with ancient viral histories might also provide clues to researchers searching for better antiviral drugs, although that remains to be demonstrated.

This article was generally well-written because it included a plethora of information conducted within the study, which allows the audience to completely understand the topic at hand. The author also included a variety of sources, whether it be experts in the field or links to other articles, ultimately establishing their credibility to the reader. Despite these areas, there are a few areas for improvement. For instance, the author repeatedly states that there were “genetic changes” in response to the epidemic from 20,000 years ago, but failed to ever explain what those changes were. Despite this, the article was an interesting read and provided intriguing information concerning the idea of modern DNA already having been exposed to coronaviruses.