FIG. 7.

Model of RdRp activities during MV infection. During the first 5 to 6 h of infection, only viral mRNAs synthesized by RdRp brought by the virions accumulated linearly (phase I). Between 5 to 6 and 10 to 12 hpi, viral mRNAs accumulated exponentially because of the additional transcriptase activities of newly synthesized RdRps (phase II). Between 10 to 12 and ∼24 hpi, some RdRp switched to replicase activity, leading to exponential accumulation of genomes and antigenomes (phase III). Between ∼24 and ∼30 hpi, viral transcripts accumulation slowed down (phase IV). In the last phase V, less and less RdRps had transcriptase activity, whereas replication somehow slowed down.