Genome map of a filovirus showing the gene order and regions of homology with proposed filovirus-like elements in mammals. Dashed lines indicate the boundaries of the non-retroviral integrated RNA virus elements (NIRVs) and depict a bias for the N-terminal region of the NP gene. Mammalian genera that show homology with a gene of filovirus are listed above the genome map. Solid colors within the coding region arrows indicate the size of the product. Red shading indicates proteins associated with the viral RNA in the ribonucleoprotein complex.