Genomic structure of a double-stranded RNA virus in the parasite Leishmania major

Viruses have been isolated in Leishmania major, which is an old world strain of the protozoan parasite Leishmania. The complete nucleotide sequence of these viruses have recently been determined and named as LRV 2-1. These viral particles can contain either a double-stranded RNA or a single-stranded RNA genome. The ssRNA particles and dsRNA particles have different sedimentation properties on centrifugation through a sucrose gradient. Northern hybridization of fractions collected from the gradient to a riboprobe of known polarity shows that the ssRNA is of positive-sense polarity. Analysis of the two different RNA species under denaturing conditions shows that they are both linear and of genome length size. The 5′-ends of the viral genome do not contain any modified structures. Although a considerate amount of sequence divergence exists between LRV 2-1 and previously described LRV 1, a virus isolated in a new world strain of Leishmania, the basic genome structure is largely similar.