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A new study led by Scripps Research Institute has shown that the novel coronavirus, SARS-CoV-2, which causes Covid-19, is of natural origin and not engineered in a laboratory.

The conclusion was made by analysing public genome sequence data from SARS-CoV-2 and related viruses. Findings from the study have been published in the Nature Medicine journal.

Scripps Research immunology and microbiology associate professor Kristian Andersen said: “By comparing the available genome sequence data for known coronavirus strains, we can firmly determine that SARS-CoV-2 originated through natural processes.”

Researchers studied the genetic template for spike proteins, which aid the virus in infecting the outer walls of human and animal cells. The focus was on the receptor-binding domain (RBD) and the cleavage site of the spike protein.

According to findings, the RBD portion evolved to target ACE2, a receptor linked to blood pressure regulation, present outside of human cells.

The observation of the SARS-CoV-2 spike protein’s effectiveness in attaching to the human cells led to the conclusion that it was through natural selection and not a product of genetic engineering.

In a statement, the researchers said: “This evidence for natural evolution was supported by data on SARS-CoV-2’s backbone – its overall molecular structure. If someone were seeking to engineer a new coronavirus as a pathogen, they would have constructed it from the backbone of a virus known to cause illness.

“But the scientists found that the SARS-CoV-2 backbone differed substantially from those of already known coronaviruses and mostly resembled related viruses found in bats and pangolins.”