According to a study conducted by researchers, it has been found that novel coronavirus first infected both the bats and pangolins and then the pathogens jumped to human beings. The researchers reportedly said that it is too early to blame the pangolins for coronavirus pandemic and they believe that a third species of animal must be involved who may have played host to the virus before it entered to the people. The study is published in journal Science Advances. A team of researchers from Duke University, Los Alamos National Laboratory reportedly said that it is quite clear that coronavirus has swapped genes repeatedly with similar strains infecting bats, pangolins, and a possible third species.
About the study
As per the study, the team analyzed 43 complete genomes from three clades of coronaviruses that infect bats and pangolins and resembles to novel coronavirus. According to the study it has been found that CoV sequences closely related to SARS-CoV-2 were obtained from confiscated Malaya pangolins in two separate studies. It added that these pangolin SARS-like CoVs form two distinct clades corresponding to their locations of origin: the first clade, Pan_SL-CoV_GD, sampled from Guangdong (GD) province in China, is genetically more similar to SARS-CoV-2 (91.2%) than the second clade, Pan_SL-CoV_GX, sampled from Guangxi (GX) province (85.4%).
The study says, “Understanding the origin of SARS-CoV-2 may help develop strategies to deter future cross-species transmissions and to establish appropriate animal models. Recombination plays an important role in the evolution of coronaviruses.” It added, “Viral sequences nearly identical to SARS and MERS viruses were found in civets and domestic camels, respectively, demonstrating that they originated from zoonotic transmissions with intermediate host species between the bat reservoirs and humans—a common pattern leading to CoV zoonosis.
However, non-human viruses nearly identical to SARS-CoV-2 have not yet been found. In this paper we demonstrate, through localized genomic analysis, a complex pattern of evolutionary recombination and strong purifying selection between CoVs from distinct host species and that cross-species infection that likely originated SARS-CoV-2.
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