Figure 4. N679K results in preference for upper airways.
(A) Schematic of experimental design of transmission competition in golden Syrian hamsters. Donor three- to four-week-old male hamsters were intranasally infected with 105 pfu of WT:N679K SARS-CoV-2 in a 1:1 ratio and housed singly. Donors were paired with recipients 24 hpi and cohoused for 8 hrs before separating and nasal washing donors. Nasal washes, tracheas, and lungs were collected at 2 and 4 days post infection for donors (dpi) and post contact for recipients (dpc).
(B) Next generation sequencing was performed on extracted RNA to measure the percentage of WT (black) and N679K (green) present in nasal wash (left), trachea (middle), and lung (right) of donors (top) and recipients (bottom).
(C) Immunohistochemistry of left lung lobes at 2, 4 and 7 dpi staining for nucleocapsid. Hamsters were singly infected with 105 pfu of either WT or N679K SARS-CoV-2.
(D) Immunohistochemistry staining of left lung lobes form hamsters infected with WT (black) or N679K (green) SARS-CoV-2 were scored by total section (left), airway (middle), or parenchyma (left) staining. Data are mean showing minimum and maximum (n=5). Statistical analysis measured by two-tailed Student’s t-test.