Positional sequencing depth of FLUBV gene segments over time. (a–h)- Positional sequencing depth for segments PB2, PB1, PA, HA, NP, NA, M and NS, respectively. The sequencing depth for each segment is shown as RNA-seq read counts at each position (5′→3′). Two replicates (indicated with superscript ‘a’ and ‘b’) from each time point (0, 6, 12 and 24 h p.i.) are shown separately.