Scientists have figured out when the coronavirus separated from bats
Evolutionary analysis of the genome of the novel coronavirus SARS-CoV-2 showed that it was separated from the most closely related viruses of bats of about 40-70 years ago. The study is published in the journal Nature Microbiology.
Biologists from the United States, Belgium, great Britain and China under the leadership of Professor David Robertson (David Robertson) from the Center for virus research University of Glasgow analyzed the evolutionary history of SARS-CoV-2. They used genomic data saribekovich — the representatives of the subgenus of coronaviruses that cause severe acute respiratory syndrome, which include including SARS-CoV and SARS-CoV-2.
It is known that coronaviruses between actively recombine — genetic material exchange, and various genomic sub-regions of the virus may have different ancestors. The task of scientists was to identify those areas of the virus, which is not subjected to recombination and that can be used for the reconstruction of its evolution.
The article reports that the closest to SARS-CoV-2 was virus bat RaTG13. Coincidences make up 96 percent of the genome, but there are differences. Obtained by the authors data suggest that the line that produced SARS-CoV-2, could circulate in bats for several decades. A similar coronavirus Pangolin-2019 has also identified the pangolins from the Chinese province of Guangdong, so the authors considered this option.
The results suggest that RaTG13 and SARS-CoV-2 have a common hereditary line, genetically different at 95 percent of the related sarcomeres bats, discovered in 1948, 1969 and 1982.
While receptornegative domain (RBD) of the protein spike of the virus, which allows him to use the human ACE2 receptor for penetration into cells, are genetically more similar to the virus pangolin, and the authors found no evidence of recombination between the line leading to SARS-CoV-2 and other known sarcomeres.
Based on this discovery, the researchers suggest that this protein and its RBD are the inherited character of the line leading to SARS-CoV-2, RaTG13 and Pangolin-2019, therefore, all these viruses have a common ancestor.
Despite this, the authors argue that the pangolins were hardly the intermediate host of the virus and is unlikely to play a significant role in the transmission of it to the man. Hereditary position adapted to human contact RBD coronavirus SARS-CoV-2 indicate that this adaptation is likely passed from bats, but for an unambiguous conclusion, according to scientists, more research is needed, based on the broader sample.
The authors note that the existing diversity and the dynamic process of recombination among clones of sarcomeres bats demonstrate how difficult it is to uniquely identify zoonotic viruses that can cause significant outbreaks among men, before their appearance, and emphasize the need to establish surveillance systems for viruses in real time. This will allow time to detect new pathogens that can cause human disease, and to classify them, scientists say.