Different mechanisms of synthesis of complete and incomplete influenza virus transcripts in infected cells.

Two types of transcripts, incomplete (polyadenylated virus-specific mRNAs) and complete (presumably templates for progeny virus replication) are synthesized in influenza virus infected cells (3). The synthesis of incomplete transcripts requires as a primer de novo synthesized host cell mRNAs (4). We show here that the synthesis of complete transcripts does not require such a primer.