Extended Data Figure 6. Construction of mouse-adapted SARS-CoV-2s with individual ORF deletions.

a, Mouse-adapted SARS-CoV-2 genome. Mouse-adapted SARS-CoV-2 (MA-SARS-CoV-2) contains three mutations in spike glycoprotein: K417E, N501Y, and Q613R. These mutations confer SARS-CoV-2 to replicate in BALB/c mice. Open reading frames, ORFs; E, envelope glycoprotein gene; L, leader sequence; M, membrane glycoprotein gene; N, nucleocapsid gene; UTR, untranslated region. b, Plaque morphologies of MA-SARS-CoV-2s with individual ORF deletions. All these ORF deletion viruses were constructed in the backbone of MA-SARS-CoV-2. Plaque assays were performed on Vero-E6 cells and stained on day 2.5 post-infection.