Evidence of the Recombinant Origin and Ongoing Mutations in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

Jiao-Mei Huang; Syed Sajid Jan; Xiaobin Wei; Yi Wan; Songying Ouyang

We also investigated some of the important evolutionary and phylogenetic aspects of SARS-CoV-2 during its spread in human population. Mutation in encoding segments of 125 SARS-CoV-2 genomes obtained from public-domain databases were investigated. In comparison with the first reported SARS-CoV-2 (Wuhan-Hu-1_MN908947), amino acid substitutions were observed at 87 positions of SARS-CoV-2 open reding frames (orfs) (Figure 3) . Total number of amino acid substitution in corresponding orfs are listed in Table 2 . Among different orfs of SARS-CoV-2, orf1a was most variable segment with total number of 44 . CC-BY 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.16.993816 doi: bioRxiv preprint dissimilar amino acid substitutions. It was followed by spike segment S orf with 13 amino acid residue substitutions. However, orf6 and orf7b are the most conserved regions without amino acid changes. In addition, orf10, E, M and orf7a have tended to be more conserved, with only one or two amino acid substitutions.