Figure 4.
Analysis of amino acid mutations in the viruses obtained by re-infection in lung tumor xenograft mouse model. The tumors derived from Calu-3 cells were infected with 1 x 106 pfu of the viral isolates (S-1, S-6, S-9) from Figure 3 . Tumor tissues were excised at 30 dpi and supernatants of the tumor homogenates were collected. Viral RNAs were extracted from the supernatants and the whole-genome sequences were analyzed. (A) Analysis of amino acid mutations in the three viral isolates (S-1, S-6, S-9) and viruses from tissue homogenates obtained at 30 dpi after re-infection (S-1/30 dpi, S-6/30 dpi, S-9/30 dpi). (B) Each panel indicates the accumulation and substitutions of mutations at an amino acid position in the viral isolates and their derivative viruses. Origin (Parent): amino acid sequences of parental SARS-CoV-2 ( Supplementary Table 1 ). dpi, days post-infection.