 Both viruses fulfill the criteria for being a member of the species Marburg marburgvirus because their genomes diverge from the prototype Marburg marburgvirus or the Marburg virus variant Musoke (MARV/Mus) by <10% at the nucleotide level.Like all mononegaviruses, marburgvirions contain non-infectious, linear nonsegmented, single-stranded RNA genomes of negative polarity that possess inverse-complementary 3' and 5' termini, do not possess a 5' cap, are not polyadenylated, and are not covalently linked to a protein.Marburgvirus genomes are approximately 19 kbp long and contain seven genes in the order 3'-UTR-"NP"-"VP35"-"VP40"-"GP"-"VP30"-"VP24"-"L"-5'-UTR.