(A) WT mice were infected with the NS1 viral library, and barcode read
profiles for each virus were analyzed at days 2–5 post-infection. Fitness
trends over time were clustered by similarity. *p < 0.05.
(B) Representative viruses exhibiting the highest barcode abundance
followed different dynamics over time and can be mainly divided into two groups.
For instance, allele B NS1 recombinant viruses showed high levels since early
after infection (continuous lines), while others, such as A/Shanghai/02/2013
(H7N9) and its phylogenetically closest related A/Chicken/Rizhao/651/2013
(H9N2), gradually increased over time. Error bars depict SD of at least 6
replicates.