Notes on Genus: Sigmavirus

enveloped bacilliform
enveloped bacilliform

Type member: Drosophila melanogaster sigmavirus


General Description

This is one of the animal virus genera in the family Rhabdoviridae. As in other genera, there are bacilliform, enveloped, particles which contain a monopartite ssRNA genome. Members infect invertebrates and are transmitted vertically through eggs and sperm. The name is taken from the type member.


Virions are bullet- or cone-shaped, about 140-200 nm long and 75 nm in diameter.


Monopartite, linear, single-stranded, negative sense RNA, about 13000 nucleotides long.

Genus Genomic Organization

There are the five structural proteins common to all members of the family and an additional gene (X) encoding a protein of unknown function situated between the P and M genes.

Type Member Genomic Organization

The genes are listed here in their order on the template strand (i.e. from 3' to 5' with respect to the virion strand):
ORF  Gene     ProductFunction
1 N 50.8 kDaCoat protein (nucleocapsid)
2 P 35.3 kDaPolymerase-associated phosphoprotein
3 X 33.8 kda Protein of unknown function
4 M 25.8 kdaMatrix protein
5 G 63.4kda Glycoprotein
6 L 241.3 kDa   Polyprotein with replicase and other functions