103.
|
Type Species |
(LRV1-1) |
Virions are isometric, 33 nm in diameter, with no envelope or surface projections (Fig. 4).
Physicochemical and Physical Properties
Virion buoyant density in CsCl is 1.33 g/cm3.
Virions contain a single molecule of linear uncapped dsRNA, 5.3 kbp in size. The complete 5,284 nts sequence is available.
Virions contain a single major capsid protein of Mr 82 103.
None reported.
None reported.
Genome Organization and Replication
The positive strand contains three ORFs. The predicted amino acid sequence of ORF3 has motifs characteristic of viral RNA-dependent RNA polymerase. ORF2 encodes the major capsid protein and overlaps ORF3 by 71 nts, suggesting a +1 translational frameshift to produce a gag-pol-like fusion protein of predicted size of 176 103. Sequencing data support the idea that the abundant ssRNA found in infected cells is the message sense RNA (Fig. 5).
Leishmania RNA virus 1 - 1 (LRV1-1) is found in infected Leishmania brasiliensis strain CUMC1. Viruses infecting several other strains of L. brasiliensis and L. guyanensis are possibly strains of LRV1-1. A single strain of L. major is known to be infected with LRV1-1-like virus. The latter is designated LRV2-1 in order to distinguish it from the viruses infecting new world strains of Leishmania.
List of Species Demarcation Criteria in the Genus
According to the virus species definition, viruses found only in distinct host species are for that reason different species. Totiviruses generally replicate stably within the cell as the cells grow. Virus strains of the same species are expected to segregate relative to each other as the cells grow, whereas those of different species should be stably co-maintained. Viruses of the same species should be similarly affected by host chromosomal mutations. Viruses that can recombine or exchange segments with each other to give viable progeny should be considered the same species. Although these biological criteria are the prime determinant of species, sequence criteria are also used. Less than 50% sequence identity at the protein level generally reflects a species difference. None of the above criteria is absolute, but totiviruses described so far leave little doubt about species demarcation.
Provisional List of Species in the Genus
Official virus species names are in italics. Tentative virus species names, alternative names ( ), strains or serotypes are not italicized. Virus names, host names { }, genome sequence accession numbers [ ], and assigned abbreviations ( ) are:
|
Leishmania RNA virus 1 - 1 |
{CUMC1} |
[M92355] |
(LRV1-1) |
|
Leishmania RNA virus 1 - 2 |
{CUMC3} (formerly LR2) |
(LRV1-2) | |
|
Leishmania RNA virus 1 - 3 |
{M2904} |
(LRV1-3) | |
|
Leishmania RNA virus 1 - 4 |
{M4147} (formerly LBV) |
[U01899] |
(LRV1-4) |
|
Leishmania RNA virus 1 - 5 |
{M1142} |
(LRV1-5) | |
|
Leishmania RNA virus 1 - 6 |
{M1176} |
(LRV1-6) | |
|
Leishmania RNA virus 1 - 7 |
{BOS12} |
(LRV1-7) | |
|
Leishmania RNA virus 1 - 8 |
{BOS16} |
(LRV1-8) | |
|
Leishmania RNA virus 1 - 9 |
{M6200} |
(LRV1-9) | |
|
Leishmania RNA virus 1 - 10 |
{LC76} |
(LRV1-10) | |
|
Leishmania RNA virus 1 - 11 |
{LH77} |
(LRV1-11) | |
|
Leishmania RNA virus 1 - 12 |
{LC56} |
(LRV1-12) | |
|
Leishmania RNA virus 2 - 1 |
(LRV2-1) |
Tentative Species in the Genus
None reported.
List of Unassigned Viruses in the Family
None reported.
Phylogenetic Relationships within the Family
Not available.
None reported.
Totus: from totus, Latin for “whole” or “undivided”.
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