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bioRxiv · 10.1101/2021.09.11.459844

Rapid and parallel adaptive mutations in spike S1 drive clade success in SARS-CoV-2

Kistler, K.·Huddleston, J.·Bedford, T.
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Abstract

Given the importance of variant SARS-CoV-2 viruses with altered receptor-binding or antigenic phenotypes, we sought to quantify the degree to which adaptive evolution is driving accumulation of mutations in the SARS-CoV-2 genome. Here we assessed adaptive evolution across genes in the SARS-CoV-2 genome by correlating clade growth with mutation accumulation as well as by comparing rates of nonsynonymous to synonymous divergence, clustering of mutations across the SARS-CoV-2 phylogeny and degree of convergent evolution of individual mutations. We find that spike S1 is the focus of adaptive evolution, but also identify positively-selected mutations in other genes that are sculpting the evolutionary trajectory of SARS-CoV-2. Adaptive changes in S1 accumulated rapidly, resulting in a remarkably high ratio of nonsynonymous to synonymous divergence that is 2.5X greater than that observed in HA1 at the beginning of the 2009 H1N1 pandemic.

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Kistler, K., Huddleston, J., Bedford, T.. 2021-09-12. Rapid and parallel adaptive mutations in spike S1 drive clade success in SARS-CoV-2. https://doi.org/10.1101/2021.09.11.459844

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