Group Group I (dsDNA) | Order Herpesvirales Rank Family | |
Similar Herpesvirales, Tetraviridae, Corticovirus | ||
Alloherpesviridae is a family of viruses within the order Herpesvirales. This family includes the species that infect fish and amphibians. Phylogenetic studies have confirmed the validity of this family and suggest that it may be divided into two clades: one consisting of viruses from cyprinid and anguillid hosts and the other of viruses from ictalurid, salmonid, acipenserid and ranid hosts. There are currently 12 species in this family, divided among 4 genera. Diseases associated with this family include: channel catfish disease.
Contents
History
This family was created in 2005.
Genomics
Several genomes have been sequenced. Cyprinid herpesviruses 1, 2 and 3 (CyHV1, CyHV2 and CyHV3) cause disease in common carp, goldfish and koi respectively. Their genomes are respectively 291144, 290304 and 295146 base pairs in size. The overall organisation common to all three and consists of a unique central region flanked by a direct repeat at each end. 137, 150, and 155 unique, functional protein coding genes are present in the unique regions respectively: of these six, four, and eight respectively are duplicated in the terminal repeat. The genomes share 120 orthologous genes in a largely colinear arrangement. Up to 55 of these latter genes are also conserved in the other member of the genus Cyprinivirus, Anguillid herpesvirus 1. CyHV1, CyHV2, and CyHV3 have five, six and five families of paralogous genes, respectively.
Taxonomy
Group: dsDNA
Structure
Viruses in Alloherpesviridae are enveloped, with icosahedral and spherical to pleomorphic geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented, around 134-248kb in length.
Life Cycle
Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of the viral glycoproteins to host receptors, which mediates endocytosis. DNA-templated transcription is the method of transcription. Fish serve as the natural host. Transmission routes are passive diffusion.