A genetic footprint has been discovered by the researchers of an ancient coronavirus outbreak by studying the genomes of modern humans from 26 worldwide populations. A new study more than 20,000 years ago, a coronavirus epidemic broke out in the East Asia region. The University of Arizona co-authors the study. They have found traces of the outbreak, which is evident in people’s genetic makeup from that area.
From 26 worldwide populations, the genomes of more than 2,500 modern humans were analyzed by the researchers. The purpose was to understand how people have adapted to historical coronavirus outbreaks. The computational method was used by researchers to find out genetic traces of adaptation to coronaviruses.
There have been three outbreaks of pandemics in the past 20 years –
- SARS-CoV is leading to Severe Acute Respiratory Syndrome. In 2002 this originated in China and killed more than 800 people.
- MERS-CoV led to Middle East Respiratory Syndrome; more than 850 people were killed.
- SARS COV-2 has killed 3.8 million people. This led to the current pandemic.
Another large coronavirus epidemic that broke out thousands of years earlier was revealed by this study of the evolution of the human genome. The ancient virus was not found directly by the researchers, but they found signatures of the natural selection imposed on human genomes during an old epidemic.
Without using living cells, the researchers synthesized both human and SARS-CoV-2 proteins. They found that these interacted directly. Evolutionary information can be found in modern human genomes tracing back hundreds of thousands of years. In this, immunological and physiological adaptions have also helped humans survive new threats, including viruses.
It was revealed in the results that the ancestors of East Asian people experienced an epidemic of coronavirus, which is similar to the current pandemic. East Asia includes Japan, Mongolia, South Korea, Taiwan, China, North Korea. A virus must attach and interact with specific proteins to invade a cell produced by the host cell. This host cell is called viral interacting proteins (VIP). Signs of adaptation were seen in 42 different human genes encoding VIPs. This suggests that over 20,000 years ago, the ancestors of modern East Asians were first exposed to coronaviruses.
42 VIPs are mainly active in the lungs, which are most affected by a coronavirus, researchers said. The virus underlying the current pandemic VIPs interact directly. Once inside, the viruses interact with many other cellular proteins. The research shows throughout the pandemic selection favored specific variants of human genes. These genes are involved in the virus-cell interactions that could have led to less severe disease.
How the genomes of different human populations adapted to viruses can best understand by analyzing the track left by ancient viruses. All these have emerged as important drivers of human evolution. The past interactions with the viruses will help researchers identify genes influencing infection and disease in modern populations. It can also help in drug development and developing new treatments. By finding the genes previously impacted by historical viral outbreaks, researchers said their study promises evolutionary genetic analyses as a new tool in fighting future epidemics.
