Sci Adv . Emergence of SARS-CoV-2 through recombination and strong purifying selection

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Sci Adv


. 2020 Jul 1;6(27):eabb9153.
doi: 10.1126/sciadv.abb9153. Print 2020 Jul.
Emergence of SARS-CoV-2 through recombination and strong purifying selection


Xiaojun Li ¹ , Elena E Giorgi ² , Manukumar Honnayakanahalli Marichannegowda ¹ , Brian Foley ² , Chuan Xiao ³ , Xiang-Peng Kong ⁴ , Yue Chen ¹ , S Gnanakaran ² , Bette Korber ^{2 5} , Feng Gao ^{6 7}



Affiliations

• PMID: 32937441
• DOI: 10.1126/sciadv.abb9153

Free article

Abstract

COVID-19 has become a global pandemic caused by the novel coronavirus SARS-CoV-2. Understanding the origins of SARS-CoV-2 is critical for deterring future zoonosis, discovering new drugs, and developing a vaccine. We show evidence of strong purifying selection around the receptor binding motif (RBM) in the spike and other genes among bat, pangolin, and human coronaviruses, suggesting similar evolutionary constraints in different host species. We also demonstrate that SARS-CoV-2's entire RBM was introduced through recombination with coronaviruses from pangolins, possibly a critical step in the evolution of SARS-CoV-2's ability to infect humans. Similar purifying selection in different host species, together with frequent recombination among coronaviruses, suggests a common evolutionary mechanism that could lead to new emerging human coronaviruses.