Comparison of the transcription and replication strategies of Marburg virus and Ebola virus by using artificial replication systems

The members of the family Filoviridae, Marburg virus (MBGV) and Ebola virus (EBOV), are very similar in terms of morphology, genome organization, and protein composition. To compare the replication and transcription strategie s of both viruses, an artificial replication system based on the vaccinia v irus T7 expression system was established for EBOV, Specific transcription and replication of an artificial monocistronic mini-replicon was demonstrat ed by reporter gene expression and detection of the transcribed and replica ted RNA species, As it was shown previously for MBGV, three of the four EBO V nucleocapsid proteins, NP, VP35, and L, were essential and sufficient for replication. In contrast to MBGV, EBOV-specific transcription was dependen t on the presence of the fourth nucleocapsid protein, VP30. When EBOV VP30 was replaced by MBGV VP30, EBOV-specific transcription was observed but wit h lower efficiency. Exchange of NP, VP35, and L between the two replication systems did not lead to detectable reporter gene expression. It was furthe r observed that neither MBGV nor EBOV were able to replicate the heterologo us minigenomes, A chimeric minigenome, however, containing the EBOV leader and the MBGV trailer was encapsidated, replicated, transcribed, and package d by both viruses.