As the world continues to grapple with the coronavirus or COVID-19, a ream of researchers comprising of scientists from China, Europe, and the US, has discovered that the lineage, which gave rise to the new virus has been circulating in bats for decades and probably includes other viruses having the ability to infect humans. The findings can be very helpful to prevent future pandemics due to this lineage.
"Coronaviruses have genetic material that is highly recombinant, meaning different regions of the virus's genome can be derived from multiple sources," Maciej Boni, who is the associate professor of biology, Penn State, said. "This has made it difficult to reconstruct SARS-CoV-2's origins. You have to identify all the regions that have been recombining and trace their histories. To do that, we put together a diverse team with expertise in recombination, phylogenetic dating, virus sampling, and molecular and viral evolution," he added.
Novel Coronavirus Evolutionary Origins
The study got published in Nature Microbiology on July 28. The researchers used three different bioinformatic approaches for identifying and removing the recombinant regions with the novel coronavirus genome. Then they reconstructed the phylogenetic histories for the non-recombinant regions and made a comparison to see which particular viruses were involved in recombination events in the past. They successfully reconstructed the evolutionary relationship between SARS-CoV-2 and the closest known bat and pangolin viruses.
The scientists found that the lineage of the new coronavirus belongs separated from the other bat viruses around 40-70 years ago. Although the new virus is genetically similar to the RaTG13 coronavirus, which got sampled from a Rhinolophus affinis horseshoe bat in 2013 in Yunnan province, China.
"The ability to estimate divergence times after disentangling recombination histories, which is something we developed in this collaboration, may lead to insights into the origins of many different viral pathogens," Philippe Lemey, a principal investigator in the Department of Evolutionary and Computational Virology, KE Leuven, stated.
The team also found that one of the older traits of the novel virus shares with its relatives is the receptor-binding domain (RBD), which was located on the Spike protein that enables the virus for recognizing and binding to receptors on the surfaces of human cells.
Coronavirus Outbreaks in Future
"This means that other viruses that are capable of infecting humans are circulating in horseshoe bats in China," David L. Robertson, the professor of computational virology, MRC-University of Glasgow Centre for Virus Research, mentioned.
Robertson further mentioned that other research groups had incorrectly proposed that key evolutionary changes happened in pangolins. The team concluded that for prevention of future pandemics, better sampling of wild bats are needed and also the implementation of human disease surveillance systems, which can identify novel viruses in humans.
"The key to successful surveillance is knowing which viruses to look for and prioritize those that can readily infect humans. We should have been better prepared for a second SARS virus," Robertson said. Boni mentioned that this outbreak is not going to be the last coronavirus pandemic and humans need to have better preparation to tackle pandemics in the future.
The deadly novel virus outbreak has created a major stir around the world in recent times infecting more than 16.4 million people worldwide and claimed the lives of over 464,000 people globally in over 170 nations. Scientists are currently working at war like speed to find a cure for the disease.