Figure 6.

Reporter influenza A viruses with genome rearrangement: Schematic representation of mutant NS (A) and PB1 (B) viral segments as described in Figure 1. (A) Bicistronic transcription of NS1 and reporter gene: A splice acceptor mutation (SAM; *) inhibits alternative splicing. Reporter protein expression occurs after 2A cleavage; (B) Bicistronic transcription of PB1 and NEP: Expression of PB1 and NEP gene products occurs by insertion of the 2A autocleavage site sequence. PB1 3′ packaging signals were duplicated after the NEP ORF and before the 3′ NCR terminus.