Portal de Periódicos da CAPES

Phylogenetic analysis of Leishmania RNA virus and Leishmania suggests ancient virus-parasite association

1995; Oxford University Press; Volume: 23; Issue: 12 Linguagem: Inglês

10.1093/nar/23.12.2300

1362-4962

Giovanni Widmer, Sheryl Dooley,

Vector-Borne Animal Diseases

Some strains of the protozoan parasite Leishmania belonging to the new world species guyanensis and brazlllensis are infected with persistent, single- segmented, non-enveloped dsRNA viruses termed LRV1.A single old world strain classified as L.major was recently found to harbor a similar virus, desig- nated LRV2-1.The genomic nucleotide sequences of two LRV1 types (1-1 and 1-4) isolated from two Lguyanensis strains have ben determined and found to be highly conserved.In contrast, LRV1-specffic cDNA probes derived from the conserved genomic 5' region failed to recognize LRV2 RNA on Northem blots, suggesting a greater degree of divergence between LRV1 and LRV2 than among LRV1 types.This observa- tion suggests a long-term association and co- evolution of LRV within each parasite strain.We tested this concept by comparing nucleotide sequences of seven LRV types and PCR fingerprints of the parasite strains from which these viruses were derived.In support of the idea of virus-parasite co-evolution, we find that genetic distances between LRV types mirror the hterogeneity between parasite fingerprints and are clustered according to the geographical origin of the strains.In agreement with the postulated common origin of persistent dsRNA viruses of protozoa and fungi, we conclude that the infection of Leishmania with LRV pre-dates the divergence of Leishmania into different lineages.