Influenza A virus segments five and six can harbor artificial introns allowing expanded coding capacity.

ABSTRACT: Influenza A viruses encode their genomes across eight, negative sense RNA segments. The six largest segments produce mRNA transcripts that do not generally splice; however, the two smallest segments are actively spliced to produce the essential viral proteins NEP and M2. Thus, viral utilization of RNA splicing effectively expands the viral coding capacity without increasing the number of genomic segments. As a first step towards understanding why splicing is not more broadly utilized across genomic segments, we designed and inserted an artificial intron into the normally nonsplicing NA segment. This insertion was tolerated and, although viral mRNAs were incompletely spliced, we observed only minor effects on viral fitness. To take advantage of the unspliced viral RNAs, we encoded a reporte

SUBMITTER: Froggatt HM 

PROVIDER: S-EPMC8496794 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature