To date most of the studies characterizing the MARV replication cycle have utilized recombinant systems, allowing for these experiments to be performed in a biosafety level 2 (BSL-2) context, unfettered by the restrictions of a BSL-4 setting. Surrogate systems mimicking specific steps in the MARV replication cycle include MARV GP-pseudotyped retroviruses or recombinant vesiculoviruses expressing GP to study entry, VLPs to study budding, and minigenome systems to study replication and transcription. While such experiments allow for the more facile examination of the MARV replication cycle, the findings must be recapitulated with infectious MARV since all surrogate systems lack elements of the infectious virus such as the distinct morphological features and virion protein composition of MARV.