FIG 3.

Phylogram and mutations of U.S. SARS-CoV-2 accessions based on the S glycoprotein. (A) Phylogenetic tree of the coding sequence for S protein based on nucleotide accessions from early (January) and middle (July and August) 2020. Color-coded rings indicate the time period and state of origin. (B) Phylogenetic tree of S protein generated using amino acid sequences from early and late time periods. (C) Mutations found in nucleotide accessions from early and late time periods. (D) Mutations found in protein accessions from early and late time periods. Amino acid 614 (G) is indicated.