Notes on Genus: Influenzavirus B

enveloped spheres or pleomorphic

Type member: Influenza B virus

Contents

Members of this Genus
General Description
Morphology
Electron Micrograph
Genome
Genus Genomic Organization
Genome Map
Type Member Genomic Organization
Curated Sequences

General Description

The genus Influenzavirus B is one of the genera in the family Orthomyxoviridae. It is named from the type (and only) member (derived from the latin influentia = epidemic). Genome organisation is very similar to that for the genus Influenzavirus A but there are large serological differences and a different organisation of RNA segment 6.

Morphology

Virions spherical or pleomorphic, enveloped, 80-120 nm in diameter, with projections 4-6 nm in diameter and 10-14 nm long.

Genome

Single-stranded negative sense RNA in 8 segments totalling about 14.6 kb. The segments do not have a genome-linked protein (VPg) at their 5'-terminus nor a 3'-polyA tail.

Genus Genomic Organization

There are 8 RNA segments. The larger genome segments each encode a single protein while the smaller segments often encode additional proteins from spliced or bicistronic mRNAs.

Type Member Genomic Organization

There are 8 RNA segments: