Fig. 1: Evolutionary trajectories of variant B.1.1.7.
From: Potential transmission chains of variant B.1.1.7 and co-mutations of SARS-CoV-2
a Incremental mutations of variant B.1.1.7. The digits in the upper-right-corner rectangle with dotted line indicate the labels of mutations. For simplicity, the 69–70 deletions were labeled as “1”, and the other mutations “2”–“9”, respectively. The bottom nodes (rectangles) represent the variants with one mutation and the top one was the early variant B.1.1.7. Each rectangle with solid line consists of lineage (e.g., B.1.243), number of strains (e.g., N:2382), mutation sites (e.g., M:----56---), the earliest collection date (e.g., 20-03-29), and collection location (e.g., USA). In the labels of the mutation sites, sign “-” indicated the corresponding site did not mutate. All routes along the directions of the arrows are possible evolutionary trajectories of lineage B.1.1.7, where the green one was the most probable mutation trajectory. Large-scale SARS-CoV-2 analysis demonstrates that the early variant B.1.1.7 might not have arisen spontaneously in the United Kingdom or within human hosts. b Co-appearances of variant B.1.1.7 mutations. At least five mutations form a potential co-mutation pattern (coappearance rate >95%). c Possible transmission chains of variant B.1.1.7. Canidae, Mustelidae or Felidae, especially the Canidae family (e.g., dog) could be a possible host of the direct progenitor of variant B.1.1.7.
