The encapsidated negative-sense RNA genome is transcribed resulting in seven monocistronic mRNAs by the viral polymerase. They are co-transcriptionally capped and polyadenylated and subsequently translated by the cellular machinery (Figure 7) . The genomic RNA also serves as the template for the production of positive-sense antigenomes, which are complementary copies of the genomes. The antigenomes are encapsidated by the nucleocapsid proteins and are in turn used as templates for genome synthesis (Figure 7 ) (for review see [68] ). As mentioned above, NP, VP35, L, and probably VP30 are needed for viral transcription and replication. Analogous to EBOV, it is conceivable that VP40 and VP24 inhibit transcription and replication [113, 185, 186] . It is hypothesized that negative regulators of replication convert the active polymerase complex into an inactive state, resulting in mature and transport-competent nucleocapsids.