The genome of Uukuniemi virus consists of three unique RNA segments.

The three RNA species isolated from virions of Uukuniemi virus, a proposed member of the newly defined Bunyaviridae family, have been characterized by analysis of 32P-labeled ribonuclease T1 oligonucleotides separated on two-dimensional polyacrylamide gels. Each species contains unique oligonucleotides not present in the two others, indicating that the genome of this virus is segmented. Each segment appears to contain a unique primary sequence with little or no overlapping among the segments. The complexities of the RNA segments as calculated from the radioactivity in unique oligonucleotides of defined lengths are about 8000 (L RNA), 3500 (M) and 1900 (S) nucleotides. Since these values are similar to the molecular weights determined by other methods, each size class of RNA corresponds to a single molecular species. The presence of a 5' terminal pppAp ... structure in each RNA segment confirms indications from electron microscopy that the apparently circular RNA segments are not covalently closed. The absence of either a 5' terminal "cap" or 3' terminal poly(A) supports the concept that Uukuniemi virus is a negative strand virus.