FIG 5.

Filovirus vsRNAs are derived primarily from structured elements in the 5′ UTRs of viral mRNAs. Shown are schematic representations of EBOV (A) and MARV (B) genome organization, with predicted secondary structures for the 5′ ends of genes from which the highest proportions of sequenced vsRNAs were derived. The nucleotides making up the 22-nt vncRNA derived from each gene are color-coded orange, and the rest of the stem-loop structure is color-coded black. The structures depicted for EBOV and MARV were computed in references 73 to 75 and were drawn here using Forna (76). Transcription start and stop signals for each gene are depicted in green and red, respectively. Black connections between genes reflect intergenic regions; overlaps between start and stop signals are staggered. For both viruses, the eGFP transgene is omitted from the schematic.