According to a recent study , the combination of genetic mixing and evolutionary selection of nearly identical genetic sequences between specific bat and pangolin coronaviruses may have led to the evolution of SARS-CoV-2 .
Analysis of 43 genomes from 3 strains of SARS-CoV-2 including bat and pangolin coronaviruses suggests that genetic combination and selection drove the evolution of SARS-CoV-2, adapting binding to the crucial pangolin virus receptor.
Zoonotic diseases are those diseases or infections whose initial vectors are animals and which can be transmitted between different host species and between the individuals of the same. For example, the famous bird flu, or bovine spongiform encephalopathy (mad cows). This is also the case for SARS-CoV-2. Not surprisingly, more than 75% of emerging diseases originate in animals . At least 10 outbreaks in the past century have spread to humans from mammals such as bats, birds, and pigs.
The results of the study, in addition to the above, also showed that the virus receptor binding motif (RBM), a component that plays a key role in the entry of the virus into host cells, was introduced through recombination with coronaviruses pangolin .
According to the study authors, the proximity of different species in a humid environment such as a market, for example, can increase the potential for cross-species infections , by allowing recombination between more distant coronaviruses and the appearance of mutations. For evolutionary selection and frequent recombination between bat, pangolin and human coronaviruses may have allowed closely related viruses to jump easily between species.
Thus, while the precise origin of SARS-CoV-2 remains unknown, this study reflects that direct human contact with wild animals must be reduced or eliminated to prevent new coronavirus zoonoses in the future. Continued surveillance for coronaviruses in their natural hosts and in humans will be key to the rapid control of new coronavirus outbreaks.