Current Biol: SARS-CoV-2-like virus found in bats proves it is naturally evolved

May 27, 2020 /
PRNewswire
BIOON /- Policy makers and the public have been debating the source of the SARS-CoV-2 virus that caused COVID-19Although researchers believe the bat is most likely the natural host of SARS-CoV-2, the origin of the virus remains unclearIn the recent journal BiologNowy, researchers described the genome of a recently discovered bat coronavirus that is highly similar to certain genomic regions of SARS-CoV-2, with the junctions of the protoprotein sajil samydnosis S1 and S2 containing amino acid insertions that are highly similar to SARS-CoV-2Although it is not a direct evolutionary precursor to SARS-CoV-2, the new virus, called RmYN02, suggests that these seemingly unusual insertion events can occur naturally during the evolution of the coronavirus, the researchers saidimage source: https://cn.bing.com
"Since SARS-CoV-2 was discovered, there has been a lot of unfounded speculation that the virus originated in a laboratory," said senior author Wei Shifeng, director of the Institute of Pathogen Biology at The First Medical University in Shandong Province, China"In particular, it has been suggested that S1/S2 insertion is very unusual and may be a sign of laboratory operationsOur paper makes it very clear that these events occur naturally in wild animalsThis provides strong evidence that SARS-CoV-2 is not a laboratory source"
researchers identified RmYN02 by analyzing 227 bat samples collected in Yunnan Province, China, from May to October 2019"Since the discovery of bats as hosts of SARS coronaviruses in 2005, there has been great interest in bats as host species of infectious diseases, especially since they carry a very rich range of RNA viruses, including coronaviruses"In early January 2020, shortly after the discovery of SARS-CoV-2, RNA from the sample was sent to macro genome next-generation sequencingthe entire genome, the virus closest to SARS-CoV-2 is another virus, known as RaTG13, previously found in bats in Yunnan provinceBut the newly discovered RmYN02 virus is more closely related to SARS-CoV-2, which is more closely related to SARS-CoV-2 in certain parts of the genome, including 97.2% RNA in the genome's longest encoded segment 1ab The researchers noted that the regions of RmYN02 that encode key receptor binding domains in the genome are not very similar to those of human ACE2 receptors used by SARS-CoV-2 to infect host cells This means it is unlikely to infect human cells The key similarity between SARS-CoV-2 and RmYN02 is that RmYN02 also contains similar amino acid insertions in two sub-bases of its spike protein SARS-CoV-2 is characterized by the insertion of a four-amino acid sequence at the junction of S1 and S2, which is unique to the virus and has so far appeared in all SARS-CoV-2 sequences The insertions in RmYN02 are different from those in SARS-CoV-2, indicating that they occur through separate insertion events However, similar insertions occurred in a virus found in bats, a strong indication that such insertions occur naturally "Our results suggest that these initially very unusual insertion events can actually occur naturally in the beta coronavirus of animals "
" our work further reveals the evolutionary ancestor of SARS-CoV-2, he added "Neither RaTG13 nor RmYN02 is a direct ancestor of SARS-CoV-2 because there is still an evolutionary gap between these viruses But our research strongly suggests that sampling more wild species will reveal viruses that are more closely related to SARS-CoV-2 and even its immediate ancestors, which will tell us a great deal about how the virus appears in humans (biovalleybioon.com) references: A close relative of SARS-CoV-2 find in in-the-bats more than the more information will be the evolved naturally Hong Zhou et al, A novel coronavirus coronavirus closely related to SARS-CoV-2 natural sats at the s1/S2 , current DOI: 10.1016/j.cub.2020.05.023