SARS-CoV-2 Emergence from Gene Shuffling Across Bats, Pangolin
New Study suggests the emergence of COVID-19 virus from evolutionary selection and gene shuffling across bats, pangolin, to humans.
A new research study claimed that the SARS-CoV-2 virus, before reaching humans could have possibly emerged from shuffling and selection of viral genes across different species like bats and pangolins.
The team led by Duke University in North Carolina said that SARS-CoV-2’s introduction into humans could be by a combination of genetic shuffling and evolutionary selection of near-identical genetic sequences among specific bat and pangolin coronaviruses leading to the evolution of SARS-CoV-2.
The study is published in the Science Advances, a peer-reviewed journal. In the study, it is showed that through recombination with pangolin coronaviruses, a component (virus” entire receptor binding motif (RBM)) that plays a key role in viral entry into host cells was introduced.
For developing a vaccine, discovering new drugs, and for deterring future zoonosis, understanding the origins of SARS-CoV-2 is critical.
The lead researcher from Duke University, Xiaojun Li explained saying, “The study suggests similar evolutionary constraints in different host species as there is evidence of strong purifying selection around the receptor-binding motif (RBM) in the spike and other
genes among bat, pangolin, and human coronaviruses.”He added, “We also show a possibly critical step in the evolution of SARS-CoV-2”s ability to infect humans, demonstrating that SARS-CoV-2”s entire RBM was introduced through recombination with coronaviruses from pangolins.”
The authors wrote, “The potential for cross-species spillover infections may increase in the proximity of different species in a wet market setting, as recombination between more distant coronaviruses and the emergence of mutations is enabled in such setting.”
Li and colleagues focused on a critical component that facilitates viral entry into host cells, the genes related to the virus” spike protein complex, and delineated which strains were most and least similar to the novel coronavirus, by analyzing 43 complete genome sequences from three strains of SARS-CoV-2-like coronaviruses from bats and pangolins.
The study suggests that common evolutionary mechanisms shaped these distinct viral strains as it was seen that the amino acid sequences from these viruses and SARS-CoV-2 were identical or nearly identical in the regions adjacent to the RBM.
Thus, the introduction of SARS-CoV-2 in humans could have been possible as the closely related viruses could readily jump between species by the evolutionary selection and frequent recombination among coronaviruses from bats, pangolins, and humans.
Though the exact origin of SARS-CoV-2 is still unknown, it is clear from this study that to prevent new coronavirus zoonoses in the future, it is critical to eliminate direct human contact with wild animals.
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SARS-CoV-2 Emergence from Gene Shuffling
