New evidence denying the 'artificial virus theory' that a coronavirus closest to the new coronavirus so far is found in wild bats?
`` A bat coronavirus with a genomic region closest to the new coronavirus (SARS-CoV-2) reported so far was found in a wild bat, '' said a research team at Shandong Daiichi Medical University in China. Was announced. This finding is likely to increase the likelihood that the new coronavirus was not created artificially, but naturally.
A novel bat coronavirus closely related to SARS-CoV-2 contains natural insertions at the S1 / S2 cleavage site of the spike protein-ScienceDirect
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Although there are various theories regarding the direct origin of human infection with SARS-CoV-2, such as pangolins , snakes , and stray dogs , the original virus is dominated by bats.
On the other hand, the idea that 'the new coronavirus was artificially created by genetic manipulation' is spreading in some areas, but experts skeptically comment on this theory.
Scientists refute the conspiracy theory that `` the new coronavirus was artificially created ''-GIGAZINE
Meanwhile, a research team led by Wen Feng Shi, a microbiologist at Shandong First Medical University, said, 'From 227 bats captured in Yunnan, China in May-October 2019, we identified new coronaviruses from bats. I did. ”
This new bat coronavirus is called 'RmYN02', and 93.3% of the genome was found to be consistent with SARS-CoV-2 as a result of gene analysis. In particular, the concordance rate in the region of the genome called '1ab' reached 97.2%, making it the closest virus to SARS-CoV-2 ever reported.
However, regarding the genome that synthesizes the protein used when SARS-CoV-2 invades human cells, the concordance rate with RmYN02 is as low as 61.3%, so there is almost no risk of infecting humans. .. It is also unlikely to be a direct ancestor of SARS-CoV-2.
On the other hand, it is also known that there are very similar characteristics between RmYN02 and SARS-CoV-2. There is a protein called 'S1 / S2 subunit ' in the spike protein (S protein) of SARS-CoV-2, but four amino acids are inserted at the junction of these two subunits. It is said that there is. Then, it was observed that an amino acid was similarly inserted in RmYN02.
Since the phenomenon that amino acids are inserted into the S1 and S2 subunits is extremely rare, it has been regarded as a strong basis for the theory that 'SARS-CoV-2 is artificially made'. .. However, this finding confirmed that a similar phenomenon occurred in RmYN02 found in nature, further supporting that SARS-CoV-2 occurred in the process of natural evolution. The team points out.
Moreover, the amino acids inserted in the S1 / S2 junction of RmYN02 and SARS-CoV-2 were different, suggesting that the insertion of amino acids in the two viruses occurred separately. It is said that it has been done.
Shi said, 'Since the discovery of SARS-CoV-2, there have been many suspicious opinions that the virus originated in a laboratory. This was based on the extremely unusual insertion of S1 / S2. Despite allegations, our findings make it very clear that these phenomena occur naturally within the body of wildlife. '
According to Shi, in the whole genome, the virus RaTG13 is the closest to SARS-CoV-2, and the concordance rate is 96.1%. However, since neither RaTG13 nor RmYN02 are said to be direct ancestors of SARS-CoV-2, Shi said, 'By collecting samples from more wild animals, the virus closer to SARS-CoV-2. I think we will find a direct ancestor. ”He stressed the importance of further research.