Download Linear map of the LSDV genome.

Morphology
large complex virion,ovoid in shape,with rounded ends and
characteristic ball of wool appearance.somewhat larger, by
electron microscopy than other poxviruses with dimensions of
294x273 nm.
The basic infectious form is the mature virion (MV).The
extracellular enveloped virion (EV) consists essentially of an MV
enclosed by an additional membrane.
The thickness(5-6 nm) and density of outer layer is consistent
with one lipid membrane bilayer,the outside of which appears
corrugated because of irregular protrusions extending 2 to
5nm.The internal structure of the virion is complex, consisting of
a dumb bell- shaped core and aggregates of heterogenous
material called lateral bodies
Between the concavities and the outer membrane.The core wall seems
to be composed of two layers with an allover thichness of 18 to 19
nm.The inner layer appears continous, except for a small number of
channels, and has a diameter and density consistent with a lipid
membrane.The outer layer has a palisade structure that is possiboly
made of T-shaped spikes (8 nm long and 5 nm wide) that are anchored
in the putative lower membrane.The ultrastructure of the core is not
resolved by cryoelectrontomograghy but appear to consist of two
phases: The denser layer just under the core wall has afiberlike
morphology , suggesting nucleoprotein. Cylindrical elements that may
take an S-shape or more complex flowerlike structures, Presumably
representing nucleoprotein , were visualized by other means within
poxvirus cores. Fields virology
Genome
The genome consists of a single molecule of linear double-stranded
DNA (Myrphy). Has linear double -stranded genome(Fields virology).
By itself, poxvirus DNA not infectious because the viral RNA
polymerase and other enzymes and factors are needed to express the
genome in the cytoplasm.(Fields virology)
The 151-kbp LSDV genome consist of a central coding region bounded
by identical 2.4 kbp-inverted terminal repeats and contains 156
putative genes. Comparsion of LSDV with chordopoxviruses of other
genera reveals 146 conserved genes which encode proteins involved in
transcription and mRNA biogenesis, nucleotide metabolism, DNA
replication, protein processing, virion structure and assembly, and viral
virulence and host range.
In the central genomic region, LSDV genes share a high degree of
colinearity and amino acid identity (average 65%) with genes of other
known mammalian poxviruses, particularly suipoxviruses,
yatapoxviruses, and leporipoxviruses. In the terminal region,
colinearity is disrupted and poxvirus homologues are either absent or
share a lower percentage of amino acid identity (average of 43%).
Most of these differences involve genes and gene families with likely
functions involving viral virulence and host range.
Although LSDV resembles leporipox-viruses in gene content and
organization, it also contains homolouges of interleukin-10 (IL-10),IL-1
binding protein, G protein- coupled CC chemokine receptor, and
epidermal growth factor -like protein which are found in other
poxvirus genera. These data show that although LSDV is closely related
to other members of chordopoxvirinae, it contains a unique
complement of genes responsible for viral host range and virulence.
Linear map of the LSDV genome.
Tulman E R et al. J. Virol. 2001;75:7122-7130
FIG. 1. Linear map of the LSDV genome. ORFs are numbered
from left to right based on the position of the methionine
initiation codon.
ORFs transcribed to the right are located above the horizontal
line; ORFs transcribed to the left are below. Genes with similar
functions and
members of gene families are colored according to the figure
key. ITRs are represented as black bars below the ORF map.
Classification of LSDV according to the International Committee
on Taxonomy of Viruses (ICTV)
Family:Poxviridae
Subfamily:Chordopoxvirinae
Genus:Capripoxvirus