Analysis of SARS-CoV-2 genome evolutionary patterns

作者：Shubhangi Gupta, Deepanshu Gupta, Sonika Bhatnagar · 发表于：Microbiology Spectrum · 年份：2024 · DOI：10.1128/spectrum.02654-23 · 被引用次数：22 · 研究领域：SARS-CoV-2 and COVID-19 Research、Animal Virus Infections Studies、SARS-CoV-2 detection and testing

ABSTRACT The spread of SARS-CoV-2 virus accompanied by public availability of abundant sequence data provides a window for the determination of viral evolutionary patterns. In this study, SARS-CoV-2 genome sequences were collected from seven countries in the period January 2020–December 2022. The sequences were classified into three phases, namely, pre-vaccination, post-vaccination, and recent period. Comparison was performed between these phases based on parameters like mutation rates, selection pressure (d N /d S ratio), and transition to transversion ratios (T i /T v ). Similar comparisons were performed among SARS-CoV-2 variants. Statistical significance was tested using Graphpad unpaired t -test. The analysis showed an increase in the percent genomic mutation rates post-vaccination and in recent periods across all countries from the pre-vaccination sequences. Mutation rates were highest in NSP3, S, N, and NSP12b before and increased further after vaccination. NSP4 showed the largest change in mutation rates after vaccination. The d N /d S ratios showed purifying selection that shifted toward neutral selection after vaccination. N, ORF8, ORF3a, and ORF10 were under highest positive selection before vaccination. Shift toward neutral selection was driven by E, NSP3, and ORF7a in the after vaccination set. In recent sequences, the largest d N /d S change was observed in E, NSP1, and NSP13. The T i /T v ratios decreased with time. C→U and G→U were the most frequent transition...