Coronavirus GenBrowser for monitoring adaptive evolution and transmission of SARS-CoV-2

COVID-19 has widely spread across the world, and much research is being conducted on the causative virus SARS-CoV-2. To help control the infection, we developed the Coronavirus GenBrowser (CGB) to monitor the pandemic. With CGB, 178,765 high quality SARS-CoV-2 genomic sequences were analyzed, and 121,522 mutations were identified. In total, 1,041 mutation cold spots were found, suggesting that these spots are key functional elements of SARS-CoV-2 and can be used for detection and vaccine development. CGB revealed 203 accelerated evolutions of SARS-CoV-2, but variants with accelerated evolution were not found to be highly contagious, suggesting that most of these evolutions are neutral. The B.1.1.7 (CGB75056.84017) lineage previously identified in the UK was not found to be significantly accelerated although its adaptive evolution was detected. Moreover, 2,297 strains with a significantly reduced evolutionary rate were identified, including three closely related variants widely spreading in Europe with no mutations in three months. By lineage tracing, a strain dated early March 2020 was determined to be the most recent common ancestor of nine strains collected from six different regions in three continents. This strain was also found to cause the outbreak in Xinfadi, Beijing, China in June 2020. CGB allows visualization and analysis of hundreds of thousands of SARS-CoV-2 genomic sequences. Distributed genome alignments and its effective analysis pipeline ensure timely update of the latest genomic data of SARS-CoV-2. CGB is an efficient platform for the general public to monitor the transmission and evolution of SARS-CoV-2.