Genetic characterization of the tick-borne orbiviruses

Manjunatha Belaganahalli (1) , Sushila Maan (2) , Narender Maan (2) , Joe Brownlie (3) , Robert Tesh (4) , Houssam Attoui (1) , Peter Mertens (1)

1 Vector - borne Viral Diseases Programme
2 Department of Animal Biotechnology
3 Department of Pathology and Infectious Diseases
4 Department of Pathology

The International Committee for Taxonomy of Viruses (ICTV) recognizes four species of tick-borne orbiviruses (TBOs): Chenuda virus, Chobar Gorge virus, Wad Medani virus and Great Island virus (genus Orbivirus, family Reoviridae). Nucleotide (nt) and amino acid (aa) sequence comparisons provide a basis for orbivirus detection and classification, however full genome sequence data were only available for the Great Island virus species. We report representative genome-sequences for the three other TBO species (virus isolates: Chenuda virus (CNUV); Chobar Gorge virus (CGV) and Wad Medani virus (WMV)). Phylogenetic comparisons show that TBOs cluster separately from insect-borne orbiviruses (IBOs). CNUV, CGV, WMV and GIV share low level aa/nt identities with other orbiviruses, in 'conserved' Pol, T2 and T13 proteins/genes, identifying them as four distinct virus-species. The TBO genome segment encoding cell attachment, outer capsid protein 1 (OC1), is approximately half the size of the equivalent segment from insect-borne orbiviruses, helping to explain why tick-borne orbiviruses have a ~1 kb smaller genome.

Domaines: Sciences du Vivant [q-bio]

Manjunatha Belaganahalli, Sushila Maan, Narender Maan, Joe Brownlie, Robert Tesh, et al.. Genetic characterization of the tick-borne orbiviruses. Viruses, 2015, 7 (5), pp.2185-2209. ⟨10.3390/v7052185⟩. ⟨hal-01604202⟩