Inside modern human DNA lie traces of ancient coronavirus infections from many, many years ago (Curr. Biol. 2021, DOI: 10.1016/j.cub.2021.05.067). Around 25,000 years ago, in fact.
That’s the conclusion of a team of researchers led by David Enard of the University of Arizona. The scientists used a large database of individual human genomes known as 1000 Genomes to compare the genes coding for proteins that interact with coronaviruses, including SARS-CoV-2. They found evidence in the DNA of people whose families came from East Asia that a coronavirus epidemic raged in that region around 25,000 years ago. In addition, the virus had changed the DNA of the survivors and their descendants.
After completing the computational genomic analysis, the researchers synthesized human and coronavirus proteins and confirmed that they interact, as suggested by the team’s earlier results. The researchers also identified previously unknown drug targets that they say could be useful for future therapeutic development.
The adaptations detected by the genomic study aren’t found in everyone in East Asia today, and the findings don’t mean that people with East Asian heritage are better adapted to survive the current COVID-19 pandemic, the researchers say. Instead, these statistical associations demonstrate that coronaviruses have been infecting humans in East Asia for thousands of years. And the impact of these earlier epidemics can be found in genomic databases today. Perhaps searching inside more human genomes might identify other evidence of ancient pandemics and the viruses that caused them.